T309-jhzh-let-pwd-qua-0453.pdf

30th Mar 2017

Jong HK, RMF

3 Months Programme Look ahead Risk and Mitigation

Construction of Siglap Station Thomson‐East Coast Line

Contract T309

2) To identify the major risk hazards and elaborate the mitigation measures in this  workshop

1) To identify the major works activities for the next three months, Apr 2017 – Jun 2017

Objectives of this workshop:

Hoarding Installation Noise Barrier installation Slab over drain works Utility Corridor Installation Road Works

Entrance C

Guide Wall & D‐Wall construction

4

Recharge Well Installation Kingpost Installation

Guide Wall & D‐Wall construction

Cooling Tower

Road Works ‐Siglap Link Drain works‐ Siglap Link Noise Panel installation Inside the Victoria School Noise Panel installation near to Laguna Park Hoarding Installation Guide Wall & D‐Wall construction

Drain Work at Keesun Avenue Noise Panel installation above Drain Noise Panel installation Siglap Linear Park Guide Wall & D‐Wall construction

Entrance B

Entrance D

Entrance A

Upcoming Works Apr 17 – Jun 17

Entrance A Drain Work at Keesun Avenue Noise Panel installation above Drain Noise Panel installation Siglap Linear Park Guide Wall & D‐Wall construction

Works at Ent. A

Noise Panel installation Siglap Linear Park

Works at Ent. A

Drain work at Keesun Ave. 

Damaged to :

Excavation  works

Insufficient  marking on  site.

Unplanned  Drilling.

Hazard  Cause

Permit to work system

Water pipe. Power grid  cables.

Risk 

Activity

•

Trial Trench

LCDW  Carry out  cable  detection

‐

TBM briefing

Sub‐con Supervisor

Tan WC (JV UE) LCDW Tan WC (JV UE) Sub‐con Engineer Sub‐con Supervisor

‐ ‐ ‐ ‐ ‐

• • • • • Thorough study of utilities drawings Cable detections by qualified LCDW Provide clear utilities marking on site Provide A3 size drawing of utility plan Apply permit to dig and implement “checklist  for working near utility” Barricade work area while trenching

Action Owner

Mitigation Measure

1) Drain Works at Keesun Ave – Risk mitigation

Soil transfer via long arm to soil truck. No stock pile on site.

1) Drain Works at Keesun Ave – Risk mitigation

Portable treatment plant commissioned to ensure silty  water are properly treated prior discharge into public  drain.

1) Drain Works at Keesun Ave – Risk mitigation

Sufficient manpower  deployed to ensure  silt are properly  maintain.

Damaged to :

Excavation  Works

Telecom  cables. High tension  cables.

Hazard 

Activity

Only  manual  excavation  is allowed  for trail  trench  works

Failure to  conduct  detection  test.

Hazard  Cause

‐ ‐ ‐

Sub‐con Supervisor Sub‐con Supervisor Sub‐con Supervisor

Mark out detected cable clearly on site.  Drill only when identified cables are exposed.  Utilities marker are only allowed to shift or remove unless approved by JV UE.

• • •

Tan WC (JV UE)

‐

• Contact relevant utility agency for any  presence of unidentified utility Always treat utility as `live’ if encountered Only manual digging allowed for trial trench Full time supervision during trial trench 

Action Owner

Mitigation Measure

Entrance B

Works at Ent. B

Guide Wall & D‐Wall construction

Entrance B

Guide wall and D‐wall construction work at Ent. B

Works at Ent. B

D‐wall work

Activity

Crane hit surrounding structures, e.g. silo

Crane Toppling

Risk 

•Load hit onto crane

•Instability of working platform

•Failure of loose material equipment/ rebar cages

Hazard Cause

2) D‐walling lifting work – Risk and Mitigation

‐

HSL LS

HSL SC

‐ • Look into min load radius when hoisting bulky items e.g. rebar cage. •Only R/S can give signal. Trade supervisor cannot involved in lifting work.

HSL R/S

HSL LS

HSL CO HSL LS

‐

‐

‐ ‐

•Signaler to communicate with crane operator

•Safety zone established

•Material shall be stacked safely and within stacking limit and load

•Low speed in lifting and lowering

JV Engineer

JV LE

‐

•Approved lifting plan, reviewed by LE and approved by PM

‐

HSL LS

‐

•Lift load by 300mm, stabilized for 3 seconds.

•Lifting points to be identified and approved

Action Owner

Mitigation Measure

D‐wall work

Activity

Crane hit surrounding structures, e.g. silo

•Banksmen to guide crawler crane movement, ensuring no tracking over drain, trench or uneven ground.

HSL R/S

HSL LS

‐ ‐

JV PM

HSL supervisor

‐

‐

HSL supervisor

‐

•Put in place the lifting permit system and display the relevant details on site.

•Instability of working platform •Ensure no overloading of crane •Failure of loose material •Signaler to communicate with crane equipment/ rebar cages operator •Lack of communication •Approved lifting plan, reviewed by LE and approved by PM •Inadequate supervision and control •Lifting operation supervised by lifting supervisor

JV Superintendent

‐

•Provide adequate hardstanding /firm working platform

crane Toppling

Action Owner

Mitigation Measure

Hazard Cause

Risk 

2) D‐walling lifting work – Risk and Mitigation

Preparation of ground access with hard‐core

2) D‐walling lifting work – Risk and Mitigation

Heavy machine on steel plate

PTW –lifting system is established

2) D‐walling lifting work – Risk and Mitigation

Lifting supervisor checking the checklist of operator

Load chart display ensuring no overloading of crane.

2) D‐walling lifting work – Risk and Mitigation

Daily checklist of machinery

Low speed in lifting and lowering

Lifting points to be identified and approved

Approved lifting plan

Lift load by 300mm, hold for 3 seconds

2) D‐walling lifting work – Risk and Mitigation

Safety zone established

Material shall be stacked safely and within stacking limit and load

Approved lifting plan for all heavy lifting on site

2) D‐walling lifting work – Risk and Mitigation

Pre‐start briefing in language understood by workmen prior lifting  work.

2) D‐walling lifting work – Risk and Mitigation

Provide exclusion zone and warning signs

2) D‐walling lifting work – Risk and Mitigation

To include min load radius in lift plan.

LM Machine not up to expectation will tagged “Not Safe for Use”

2) D‐walling lifting work – Risk and Mitigation

Utility Corridor Installation Road Works

Slab over drain Construction

Noise Barrier installation

Entrance C Hoarding Installation

Works at Ent. C

Fall from  height

Noise  barrier  Erection

MEWP topple

Hit by fallen  object

Risk

Activity

Over loading  of MEWP

Poor footage

Failure to  provide  control

Failure to  provide fall  protection  provision

Hazard  Cause

3) Noise Barrier Erection – Laguna Park

Richee engineer  JV Safety Dept. Richee Supervisor Richee Supervisor Richee Supervisor Richee Supervisor

‐ ‐ ‐ ‐ ‐ ‐

• • • • • • Provision of Fall Protection Plan. Establish PTW‐Height system. Provide proper access. Provide adequate work platform. Licensed MEWP operator. Familiarisation briefing prior appointment.

Action Owner

Mitigation Measure

Fall from  height

Noise  barrier  Erection

MEWP topple

Hit by fallen  object

Risk

Activity

Over loading  of MEWP

Poor footage

Failure to  provide  control

Failure to  provide fall  protection  provision

Hazard  Cause

3) Noise Barrier Erection – Laguna Park

• • • • •

‐ ‐ ‐ ‐ ‐

Richee Supervisor MEWP Operator JV Engineer Richee Supervisor Richee Supervisor

Richee engineer  JV Safety Dept. Richee Supervisor Richee Supervisor Richee Supervisor Richee Supervisor Richee Supervisor

‐ ‐ ‐ ‐ ‐ ‐ ‐

• • • • • • • Provision of Fall Protection Plan. Establish PTW‐Height system. Provide proper access. Provide adequate work platform. Licensed MEWP operator. Familiarisation briefing prior appointment. Enveloped MEWP work platform with scaffold  netting to contain material. Limit max. 2 person on MEWP. Max. weight 120kg. Firm and compacted ground for MEWP access. Provide adequate exclusion zone and signage. Provide banksman to ensure no authorised  entry in to work zone.

Action Owner

Mitigation Measure

Laguna  Park

Public interface during Noise  barrier erection – mitigation  measures

3) Noise Barrier Erection – Laguna Park

Entrance C construction  work in progress

Provide exclusion zone and banksman to prevent  unauthorised entry.

3) Noise Barrier Erection – Laguna Park

Include min load radius in load chart

Welding work with fire screen, extinguisher and fire  watchman standby.

3) Noise Barrier Erection – Laguna Park

No welding during wet weather.

Works at Ent. D

Guide Wall & D‐Wall construction

Road Works ‐Siglap Link Drain works‐ Siglap Link Noise Panel installation Inside the Victoria School Noise Panel installation near to Laguna Park Hoarding Installation

Entrance D

Noise Panel installation near to Laguna Park

Works at Ent. D

Noise Panel installation Inside the Victoria School

Guide Wall & D‐Wall construction Recharge Well Installation Kingpost Installation

Cooling Tower

Cooling Tower Works

“A’ frame  topple

Recharge  well work

Fingers / hand  caught in  rotating parts

Injury to public

Risk 

Activity

Incompetent  crew

Poor ground  condition

Poor footage

Poor  mobilization  planning

Hazard  Cause

4) Recharge Well work – Risk mitigation

• •

• •

• •

•

‐ ‐

‐ ‐

‐ ‐

‐

JV Lift Engineer Sub‐con lifting supervisor

Sub‐con supervisor Sub‐con supervisor

Sub‐con supervisor Sub‐con supervisor

Sub‐con Engineer

JV Superintendent JV Supervisor

‐ ‐

• • Ensure work assess is planned. Ensure adequate access for work mobilisation  and public access. Only competent lifting crew is allowed to  involved in mobilisation. PTW‐Lifting approved prior unloading. Provide proper exclusion zone to segregate  work and public. Provide warning signs. Provide blinker lights to alert night motorist  and /or pedestrian. Ensure footage is firm and level at all times. Never drag load. Lift vertically.

Action Owner

Mitigation Measure

4) Recharge Well work – Risk mitigation

Installation  of kingpost

Activity

Machine to be inspected and certified  by AE. Regular monthly maintenance of  machineries

•

Installed sound barrier Used of silent piler Refrain from working at night and  weekend/PH Additional sling tied to sheet pile and machinery as extra protection in case  grabber gives way.

•

Accidental  Carelessness and inexperience  dislodgement of  operator. kingpost during Faulty vibro hammer. driving

•

• • •

Structure failure of machinery..

‐Sub‐con supervisor

‐ JV superintendent

‐ JV Superintendent

‐ Sub‐con supervisor

‐ Sub‐con supervisor

‐ Sub‐con supervisor

‐ JV Engineer

Access to be laid with hardcore and  compacted. I beam to be properly stacked and  excluded.

• •

Action Owner

Mitigation Measure

Old machinery and poor  maintenance causing  disturbance to nearby resident.

Noise pollution

Using of poor  condition  machinery

Toppling of machinery resulting  in damage to property.

Poor ground  condition

Injury to surrounding people.

Hazard Cause

Risk 

5) Installation of Kingpost ‐ Risk mitigation

Collision of  machinery and site  people.

Installation of kingpost

Kingpost installation

Hazard

Activity

5) Installation of Kingpost ‐ Risk mitigation

Mitigation Measures

Risk Owner

Machines /man are not  allowed to be too close.  Provide  adequate  exclusion zone. 

Constraint of work  ‐ Work zone to be barricaded to  ‐ Sub‐con supervisor area  prevent unauthorized entry ‐ Used of tag line to control swaying  ‐ Sub‐con R/S of load. ‐ JV  Superintendent Only allow skilled operator and  experienced lifting team. 

Hazard Cause

Poor ground  condition

Installation of kingpost

Toppling of machinery resulting  in damage to property Injury to surrounding people

Hazard Cause

Access laid with hardcore and compacted

Hazard

Activity

3) Installation of Kingpost ‐ Risk mitigation

‐ Sub con LS

‐ Sub‐con supervisor

Risk Owner

Piling PTW system inplace.

‐ Access to be laid with  hard‐core and compacted. ‐ kingpost to be laid on  top of hard‐core.

Mitigation Measures

Maintenance service report, AE inspection  checklist and certificate

Using of poor condition  Structure failure of  machinery machinery

Installation of kingpost

Hazard Cause

Hazard

Activity

5) Installation of Kingpost ‐ Risk mitigation

‐ Machine to be  inspected and certified  by AE. ‐ Regular monthly  maintenance of  machinery 

‐ Sub‐con supervisor

‐ Sub‐con supervisor

Mitigation Measures Action Owner

Hazard

Hazard Cause

Re‐charge well reservoir 

Installation of sheet  Noise pollution Old machinery and poor  pile maintenance causing  disturbance to nearby resident

Activity

5) Installation of Kingpost ‐ Risk mitigation

‐ JV  Superintendent

Action Owner

Sound barrier set up at cooling tower during  kingpost driving to shield the nearby resident.

Installed sound barrier Used of silent piler Refrain from working at night  and weekend/PH

Mitigation Measures

End

100

100

T309/CNSS

T309/CNSS

ERSS for Temporary Work

008

007

T309/CDSS/100/008

T309/CDSS/100/007

Trenching

Lifting with crane

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

Instability of temporary works (trenches)

● Differential settlement between station ERSS ● Failure of loose material, equipment/ rebar cage ● Instability of working platform

Hazard

4

5 Hazard Cause

ERSS wall construction within F1 soil layer - F1 soil layer collapse - Trench stability

- Not identifying the behaviour and response of the ground and adjacent structures

Flawed design of temporary works - Inappropriate use / misinterpretation of design codes - Lack of understanding of design software and output - Incorrect information on adjacent structures - Temporary works design is incompatible with adjacent structures

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Doc no: T309-JHZH-RAR-PWD-RIS-0001

- Collapse of temporary works - Excessive movement/Collapse of adjacent structures - Injury or fatalities of public and Construction workers

- Collapse of temporary works - Collapse / damage of adjacent structures - damage of permanent works - Injury or fatality of construction workers or public

Impact

6

The Risk Register is a "live document" and it will be the responsibility of all parties involved in the design, construction and commissioning of the T309 Project and to ensure that all reasonable means and measures are put in place for the effective management of all the safety risks.to continue to identify new risks that arises.

e

Package 1

F

V

V

V

7

I

I

I

S

C

C

C

Ri

Initial Risk Category Ri

8

- Contractor to produce robust design - Appropriate design sensitivity - Specify minimum penetration of panels - Additional site investigation - Pre-qualify contractors - Emergency Response planning - Provide temporary strut with PE endorsement

- Review levels to be developed - Regular review of Instrumentation / monitoring e.g. LBs to monitor building movement, LGs for ground movement and IW or XYZ for ERSS. - Approved Permit to lift and lifting plan - Lifting Supervisor to ensure correct method of usage - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Avoid loading and unloading near edge of properties or access walkways - Low speed in lifting and lowering of material '- Signaller to communicate with crane operator during lifting and lowering operation - Lifting points to be identified, marked and approved

- Contractor to produce robust design - Approved Permit to lift and lifting plan - Lifting Supervisor to ensure correct method of usage - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Avoid loading and unloading near edge of properties or access walkways - Low speed in lifting and lowering of material '- Signaller to communicate with crane operator during lifting and lowering operation - Lifting points to be identified, marked and approved

Mitigation Measures

I

I

V

V

I

S

V

F

C

C

C

Ri

Residual Risk Category Rr

11

12

JHZH-PM - Regular review instrumentation reading - Perform probing and SI (SPT) at regular intervals - Perform Ground Improvements when necessary - Joint inspection between JHZHJV and QPS for every Dwall 1) Mild case (to read; less than 10% of total panel excavated volume) – Create an earth bund wall surrounding the affected panel, fill up the bund wall pool with bentonite to increase the bentonite head level. 2) Moderate case (to read; more than 10% of total panel excavated volume, without any visual ground/ platform depression) – Move the grabber and other unnecessary heavy equipment at least 20m away from the affected panel, and backfill the panel with LSS to the ground level by tremie method. 3) On a case by case basis for a severe case (to read; more than 10% of total panel excavated volume, with obvious visual ground/ platform depression) – Move all machinery away except excavator at least 20m away from the affected panel, and backfill the panel with LSS to the ground level by tremie method. After 24 hours of backfilling, conduct light cement grout beneath the depressed platform.

JHZH-PM

JHZH-PM

- Steel plate to ensure uniform loading of crane JHZH-PM weight and outrigger - Use of level indicator and inclinometer - Additional site investigation when necessary - Lifting zone to be barricaded before works commence 1) Mild case (to read; less than 10% of total panel excavated volume) – Create an earth bund wall surrounding the affected panel, fill up the bund wall pool with bentonite to increase the bentonite head level. 2) Moderate case (to read; more than 10% of total panel excavated volume, without any visual ground/ platform depression) – Move the grabber and other unnecessary heavy equipment at least 20m away from the affected panel, and backfill the panel with LSS to the ground level by tremie method. 3) On a case by case basis for a severe case (to read; more than 10% of total panel excavated volume, with obvious visual ground/ platform depression) – Move all machinery away except excavator at least 20m away from the affected panel, and backfill the panel with LSS to the ground level by tremie method. After 24 hours of backfilling, conduct light cement grout beneath the depressed platform.

*Action Owner

JHZH-PM

Risk Owner

- Steel plate to ensure uniform loading of crane JHZH-PM weight and outrigger - Use of level indicator and inclinometer - Additional site investigation when necessary - Emergency Response planning including Contingency planning e.g. stop all excavation, ensure safe escape route for workers, additional temporary struts. - Lifting zone to be barricaded before works commence - Lift load by 300mm, hold for 3 seconds, all personnel 3m away Approved lifting plan, reviewed by LE and approved by PM - Lifting points to be identified and approved - Low speed in lifting and lowering - Material shall be stacked safely and within stacking limit and load - Safety zone established - Signaler to communicate with crane operator

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Summary of Residual Risk Classes A 0 B 0 C 51 D 15 66

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

Summary of Initial Risk Classes A 0 B 11 C 48 D 7 66

Apr-17

Apr-17

Apr-17

Due Date By

Revision G 13 14

7 months

7 months

7 months

Risk Exposure Period

C

C

ipe

Target Risk Rating

Open

Open

Open

Status

Date: 27/04/2017 15 16

17 Remarks

011

012

100

100

T309/CNSS

T309/CNSS

T309/CDSS/100/012

T309/CDSS/100/011

T309/CDSS/100/010

010

100

T309/CNSS

T309/CDSS/100/009

009

100

T309/CNSS

Construction of ERSS for Utility Diversion

Construction of ERSS for Drain Diversion

Construction of ERSS

Construction of ERSS

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

Instability of temporary works (Utility Diversion ERSS)

Instability of temporary works (Drain Diversion ERSS)

Excessive ground movement of adjacent structures and utilities

Instability of temporary works (ERSS failure)

Hazard

4

5 Hazard Cause

6 Impact

F

Structural damage/deflection of existing structures - Damage to utilities - Traffic accidents with associated injuries - injuries to public or construction workers associated with ramp distress - Damage to road surfaces - Wall toe movement

- Damage to utilities - Damage to road surfaces

-Higher than expected lateral deflection of ERSS wall during excavations - Unforeseen ground conditions - Inappropriate removal of struts - Over-excavation - Excavation for the utilities laying/trench

- Unforeseen higher than designed surcharge

- Damage to utilities - Damage to road surfaces

- Unforeseen higher than designed surcharge

IV

IV

III

III

III

III

IV

- Injuries to public or construction workers associated with ramp distress - Traffic accidents with associated injuries - Structure Integrity of sheet piles.

- Inappropriate removal of struts - Over-excavation - Excavation for the drain and damage ERSS - Sheet pile obstructed and not able to pile into required depth. -Poor quality weld and design of sheet pile bracing.

IV

III

III

III

IV

IV

IV

I

I

V

V

I

I

S

V

V

7

C

C

C

C

C

C

C

C

C

C

C

Ri

Initial Risk Category Ri

- Structural damage/deflection of existing structures - Damage to utilities - Injuries to public or construction workers associated with ramp distress - Damage to road surfaces - Wall toe movement

Structural damage/deflection of existing structures - damage to utilities - Traffic accidents with associated injuries - injuries to public or construction workers associated with ramp distress - damage to road surfaces - Wall toe movement

Package 1 8

- PE to ensure surcharge level to within acceptable loading

- Contractor to produce robust design - Method Statements to ensure safe working methods - Monitoring on site - Gather knowledge from people with relevant experience - Visual inspection

- PE to ensure surcharge level to within acceptable loading

- Method Statements to ensure safe working methods -Follow the PTW (e.g excavate) daily during work - Review design of sheet pile and provide COS. - Only certified and appointed welders are allowed to weld. - Method statement to ensure proper bracing is provided.

- Contractor to produce robust design - Method Statements to ensure safe working methods - Gather knowledge from people with relevant experience

- PE to ensure surcharge level to within acceptable loading

- Contractor to produce robust design - Method Statements to ensure safe working methods -Regular review instrumentation reading - Apply PTW (e.g. excavate) daily before commencement of work

- Calculate amount of bentonite level required

- Robust Contractor's ERSS system - Pre-qualify contractors

- Contractor to produce robust design - Appropriate design sensitivity

- Contractor’s Method Statements - Apply PTW (e.g. excavate) daily before commencement of work '- Emergency Response Planning including Contingency planning e.g. grouting of gaps - Additional site investigation

Mitigation Measures

V

V

III

III

III

III

V

V

III

III

III

I

I

V

IV

IV

V

V

I

I

V

V

S

F

D

D

D

D

D

C

C

C

C

C

C

Ri

Residual Risk Category Rr

11

- No stockpiling

JHZH-PM

-Provide ground improvements when necessary JHZH-PM - Requirements to record penetration into competent stratum on installation -High quality site records -Bearing capacity checks for construction equipment - Installation of additional recharge wells & pressure relief wells as contingencies.

- No stockpiling

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM - instrumentation/monitoring to monitor strut loads. - Daily physical inspection of strutting system

JHZH-PM

JHZH-PM

JHZH-PM -Statutory requirement for QP(Sup) to be responsible for supervision of temporary works. -Emergency Response planning including Contingency planning

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

-Normal/ established procedures for staging the JHZH-PM works to protect adjacent utilities -Permit to remove strut system followed to prevent inappropriate removal of struts -Emergency Response planning including Contingency Planning

- No stockpiling

12 *Action Owner

JHZH-PM

JHZH-PM

Risk Owner

- Control of excavation opening to pouring time JHZH-PM

- High quality construction records - Ensure trench stability - Emergency Response planning

- instrumentation/monitoring to monitor strut loads. - Daily physical inspection of strutting system

-Emergency Response planning including Contingency planning -Instrumentation/monitoring to monitor strut loads. - Instrumentation/ real time monitoring - Perform probing and SI (SPT) at regular intervals - Sufficient vibration monitors with appropriate trigger levels to be installed. - Provision of recharge wells. -Provide proper recharging system -Provide proper filter gravel

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

-Higher than expected lateral deflection of ERSS wall during excavations - Unforeseen ground conditions

- Unforeseen higher than designed surcharge

Higher than expected lateral deflection of ERSS wall during excavations - Unforeseen ground conditions - Inappropriate removal of struts - Over-excavation - Excavation of cut and cover tunnel

- Low bentonite level

Inadequate structural detail connection between - Collapse of temporary works strut, waler to ERSS walls / shafts / excavations - Excessive movement/Collapse of adjacent structures - Injury or fatalities of public and Construction workers - Contractor's ERSS design - Workmanship

- Groundwater drawdown

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Apr-17

Oct-17

Apr-17

Apr-17

Apr-17

Apr-17

Apr-17

Apr-17

Apr-17

Apr-17

Mar-17

Due Date By

Revision G 13 14

7 months

13 months

7 months

7 months

7 months

7 months

7 months

7 months

7 months

7 months

7 months

Risk Exposure Period

C

C

C

C

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Open

Open

Open

Open

Status

Date: 27/04/2017 15 16 17 Remarks

100

100

T309/CNSS

T309/CNSS

014

013

N.A

NA

4

Gaps in sheet piles

Hazard

- Instability of temporary works (kingpost for traffic decking - ERSS) -Poor ground condition Construction of ERSS -Using of poor condition machinery (Kingpost) - Noise pollution for traffic decking -Accidental dislodgement of kingpost during driving -Collision of machinery and site people.

Construction of ERSS (Drainage diversion)

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

5 Hazard Cause

- Poor design lead to undersize kingpost. - Poor workmanship. -Overloading of kingpost with other load not considered in the design. -Toppling of machinery resulting in damage to property. -Injury to surrounding people. -Structure failure of machinery.. -Old machinery and poor maintenance causing disturbance to nearby resident. - Carelessness and inexperience operator. Faulty vibro hammer.

- Supporting structure across the excavation due to lack of diversion corridor

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

- Collapse of temporary works - Collapse / damage of adjacent structures - damage of permanent works - Injury or fatality of construction workers or public

- Leakage through gap in the walls - Damage to services - Groundwater drawdown - Localized collapse of soil in the gap during excavation

Impact

Package 1

IV

7

III

S IV

F III

C

C

Ri

Initial Risk Category Ri

8

- Method Statements to ensure kingpost is constructed according to MS -JV engineer / QPS to supervise kinghpost construction work to esnure quality of workmanship. - Design to allow sufficient safety factor for structure interity of kingpost. -Access to be laid with hardcore and compacted. -I beam to be properly stacked and excluded. -Machine to be inspected and certified by AE. -Regular monthly maintenance of machineries - Work zone to be barricaded to prevent unauthorized entry - Used of tag line to control swaying of load. - Only allow skilled operator and experienced lifting team.

- Minimize gaps to minimum size required - Utilities diverted from excavation wherever possible - Instrumentation around gap area when necessary

Mitigation Measures

V

III

S IV

F IV

D

D

Ri

Residual Risk Category Rr

11 Risk Owner

- During construction phase, ensure RA control measure are implemented - e.g. -Segregation of man and machines -Provide designated pedestrian access for wokers. - Provide adequate warning signs. - Provide proper barricades around bore hole. -Installed sound barrier - Used of silent piler - Refrain from working at night and weekend /PH - Additional sling tied to sheet pile and machinery as extra protection in case grabber gives way. - Access to be laid with hard-core and compacted. - kingpost to be laid on top of hard-core.

JHZH-PM

JHZH-PM - Reinstall sheet piles if there are gaps during installation - Emergency Response Planning including Contingency Planning (e.g. immediate removal works upon sighting of unfavaourable ground/wall movements) 1) Mild case (to read; less than 10% of total panel excavated volume) – Create an earth bund wall surrounding the affected panel, fill up the bund wall pool with bentonite to increase the bentonite head level. 2) Moderate case (to read; more than 10% of total panel excavated volume, without any visual ground/ platform depression) – Move the grabber and other unnecessary heavy equipment at least 20m away from the affected panel, and backfill the panel with LSS to the ground level by tremie method. 3) On a case by case basis for a severe case (to read; more than 10% of total panel excavated volume, with obvious visual ground/ platform depression) – Move all machinery away except excavator at least 20m away from the affected panel, and backfill the panel with LSS to the ground level by tremie method. After 24 hours of backfilling, conduct light cement grout beneath the depressed platform.

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

12

JHZH-PM

JHZH-PM

*Action Owner

Apr-17

Apr-17

Due Date By

Revision G 13 14

7 months

7 months

Risk Exposure Period

C

C

Target Risk Rating

Open

Open

Status

Date: 27/04/2017 15 16 17 Remarks

102

102

102

102

102

102

102

Diaphragm walling T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

007

006

005

004

003

002

001

NA

NA

N.A

T309/CDSS/102/004

T309/CDSS/102/003

T309/CDSS/102/002

T309/CDSS/102/001

Barrette pile test

Welding Works with Welding inverter

Welding Works with Oxygen acetylene and Welding inverter

Diaphragm walling

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

5

-Instability of ERSS wall trenches - Low shear strength in Marine Clay - Loose fills - Possible removal of buried obstructions - Presence of thick peaty layers - High pore water pressure in Marine Clay - Close proximity of adjacent activities such as jet grout piles or casting of nearby trench -Leakage of Bentonite from D wall -Poor Bentonite mixe.

Hazard Cause

6

- Structural damage/deflection of existing structures - Damage to utilities - Traffic accidents with associated injuries - Damage to road surfaces - Collaspe of D wall

Impact

7

Kentledge collapse

- Failure of jack, jack force is not locked in - Unbalance pressure force in jack

- Testing of D-wall

- Improper maintenance of welding set - Improper connection and damaged cables - welding set not fully protected from wet surfaces - Welding in open space during wet weather condition

- Injury to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Injury to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Injury to public or construction personnel - Delays - Claims -Reputation

IV

IV

IV

I

I

I

II

IV

- Injury to public or construction personnel - Delays - Claims - Damage to permanent and temporary works

Fire sparks, fire explosion - Inappropriate welding of struts - Inappropriate welding of Traffic Deck due to Gas leaks, hose damaged, fitting damaged - Inappropriate welding of Noise Barriers - Incompetent welder deployed

Electrocution due to electrical leak

III

V

III

III

V

V

II

S

IV

F

B

B

B

C

D

D

D

C

Ri

Initial Risk Category Ri

- Water ingress - Lost toe stability - Loss of fines - Settlement of structures

- Delay of works -Inappropriate diaphragm wall design - Inappropriate use / misinterpretation of design codes

Package 1 8

- Contractor shall provide -uniform hydraulic pressure supply to all jacks to main balance force in test - Mechanical safe lock (safety valve) to lock pressure in jack during jack operation in case of pressure loss

- Test set up must get endorsement of PE

- PPE: Welding face shield, apron and gauntlet - Apply PTW (e.g. hot works) daily before commencement of work - Electrical wires to be secured above ground - Daily welding set checklist/ inspection - Certified welders - Reminder in Tool box meeting

- PPE: Welding face shield, apron and gauntlet - Proper housekeeping - Method Statements (e.g. - Close main value & flush hose line after usage) - Apply PTW (e.g. hot works) daily before commencements of works - Daily welding set checklist/ inspection - Fire extinguishers and fire blankets - Reminder in Tool box meeting '- Certified welders - Welding screen to contain sparks

- Specifying waterproofing details @ interface

- Use of adequate plant / equipment for diaphragm wall construction -Apply PTW (e.g. lifting) daily before commencements of works - Cage to be within lifting equipment capacity - Lifting points to be identified, marked and approved

- Emergency Response Planning including Contingency planning e.g. grouting of gaps - Method Statements to ensure safe working methods - Apply PTW (e.g. excavate) daily before commencement of work

- Method Statements to ensure safe working methods - Regular monitoring of critical structures - Stability calculations - Contingency planning e.g. (backfilling) in case of collapse, additional temporary struts - Trial panel - Raised guide walls - Control of bentonite properties (e.g. viscosity, sand content, PH value, density) - Visual inspection - Pre-qualify contractors -Apply PTW (e.g. excavate) daily before commencement of work - Deploy worker to monitor Bentonite level especially over week end.

Mitigation Measures

V

V

V

V

V

I

I

I

I

III

III

III

V

V

II

S

IV

F

C

C

C

C

D

D

D

C

Ri

Residual Risk Category Rr

11 Risk Owner

12

JHZH-PM

- Provide physical barrier (interlocked properly) JHZH-PM and safety signs around test sites - Emergency Response planning including Contingency planning - Proper design of kentledge system - Pre-qualify the subcontractor - Approved Method Statement

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

*Action Owner

JHZH-PM

JHZH-PM

-Monitoring of overall settlement and differential JHZH-PM settlement of the kentledge - Provide physical barrier (interlocked properly) and safety signs around test sites - Emergency Response planning including Contingency planning - Proper design of kentledge system - Pre-qualify the subcontractor - Approved Method Statement

-No welding work under rain weather/ wet surfaces - Monthly inspection of welding equipment - Apply Safe Work procedure - Electrical neoprene cable double insulated

- Remove flammable items (timber, canvas etc.. )from welding premises - Monthly inspection of welding equipment - Apply Safe Work Procedure - Implement PTW -Hot work

- High quality construction inspection and records - Method Statements to ensure safe working methods - Use of adequate plant/equipment for ERSS wall construction

- Adopt approved lifting plan - Ensure lifting equipment are inspected monthly - Lifting zone to be barricaded before works commence

- Proper post-cast for structure - Specifying waterproofing details @ interface

-Normal/ established procedures for staging the JHZH-PM works to protect adjacent utilities -Regular review instrumentation reading -Permit to remove strut system followed to prevent inappropriate removal of struts -No stockpiling against D-wall -Emergency Response planning including Contingency planning - Never start D-walling without having the cages ready.

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

Inadequate water tightness - Poor concrete compaction - Inadequate concrete cover and reduced durability due to honeycomb - Poor workmanship

Diaphragm wall cage too heavy to be lifted

Gaps in retaining systems Provision for services to pass through retaining -Cracking / leakage systems - Structural Damage - Waterproofing problems and associated repair

Excessive ground movement of adjacent structures and utilities

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Mar-17

Mar-17

Oct-17

Oct-17

Oct-17

Oct-17

Oct-17

Oct-17

Due Date By

Revision G 13 14

7 months

7 months

13 months

13 months

13 months

13 months

13 months

13 months

Risk Exposure Period

C

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Open

Status

Date: 27/04/2017 15 16 17 Remarks

102

102

102

102

102

T309/CNSS

T309/CNSS

Pilling T309/CNSS

T309/CNSS

T309/CNSS

011

010

009

009

008

NA

T309/CDSS/102/004

T309/CDSS/102/001

NA

NA

Bored pile test

Piling

Lifting with crane

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

5

-Instability of ERSS wall trenches - Low shear strength in Marine Clay - Loose fills - Possible removal of buried obstructions - Presence of thick peaty layers - High pore water pressure in Marine Clay - Close proximity of adjacent activities such as jet grout piles or casting of nearby trench

Kentledge collapse

- Failure of jack, jack force is not locked in - Unbalance pressure force in jack

- Bored Pile testing

Inadequate water tightness - Poor concrete compaction - Inadequate concrete cover and reduced durability due to honeycomb - Poor workmanship

Excessive ground movement of adjacent structures and utilities

- Poor design - Poor workmanship - Poor rigging method

- Improper securing of material/ equipment/ cages - Overloading of material/ equipment/ cages - Slight tilt in crane '- Sudden movement of crane boom

Failing of loose material/ equipment/ rebar cages

In Stability of rebar cage (including cages for Lshape d-wall panel)

- Breakage of lifting chain - Breakage of lifting sling - Failure of brake motor/gear - Failure of sling/chain buckles and hooks - Overloading of carried loads over limited of design capacity - Unauthorized modification of lifting points -Inadequate rigging method.

Hazard Cause

Failure of lifting mechanism

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

7

- Injury to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Injury to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Water ingress - Lost toe Stability - Loss of fines - Settlement of structures

- Structural damage/deflection of existing structures - Damage to utilities - Traffic accidents with associated injuries - Damage to road surfaces

IV

IV

V

IV

IV

I

I

III

II

I

I

IV

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Injury to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities - Rebar cage fall off during lifting process. - Crane damanged by swing load e.g. windscreen damaged by lifted rebar cage.

I

S

IV

F

B

B

D

C

B

B

B

Ri

Initial Risk Category Ri

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities -Crane topple -Tanish reputation

Impact

Package 1 8

- Contractor shall provide -uniform hydraulic pressure supply to all jacks to main balance force in test - Mechanical safe lock (safety valve) to lock pressure in jack during jack operation in case of pressure loss

- Test set up must get endorsement of PE

- Use of adequate plant / equipment for ERSS wall construction

- Method Statements to ensure safe working methods - Regular monitoring of critical structures - Stability calculations - Contingency planning e.g. (backfilling) in case of collapse, additional temporary struts - Trial panel - Raised guide walls - Control of bentonite properties (e.g. viscosity, sand content, PH value, density) - Visual inspection - Pre-qualify contractors - Apply PTW (e.g. piling) daily before commencement of work

- Cage design must get endorsement of PE - Regular inspection of interface with good records - Lifting points to be marked, identified and approved - Engineer to be present to confirm lifting points prior liftng rebar cage. - Ensure moin load radius is taken into consideration when preparing lift plan.

- Approved PTW (e.g lifting) daily before commencement of work - Lifting Supervisor to ensure correct method of usage - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Avoid loading and unloading near edge of properties or access walkways - Low speed in lifting and lowering of material '- Signaller to communicate with crane operator during lifting and lowering operation - Lifting points to be marked, identified and approved - Approved Lifting plan - Material shall be stacked safely and within stacking limit and load

- Apply PTW (e.g. lifting) daily before commencement of work - Monthly inspection of lifting mechanisms - Lifting Supervisor to ensure correct method of usage - Colour coding all lifting mechanisms for validity and serviceability levels - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Lifting points to be marked, identified and approved - Approved Lifting Plan -Weekly boom down inspection with mechanics

Mitigation Measures

V

V

V

IV

I

I

III

II

I

I

V

V

I

S

V

F

C

C

D

C

C

C

C

Ri

Residual Risk Category Rr

11

12

JHZH-PM

JHZH-PM

- Provide physical barrier (interlocked properly) JHZH-PM and safety signs around test sites - Emergency Response planning including Contingency planning - Proper design of kentledge system - Pre-qualify the subcontractor - Approved Method Statement

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

*Action Owner

JHZH-PM

Risk Owner

-Monitoring of overall settlement and differential JHZH-PM settlement of the kentledge - Provide physical barrier (interlocked properly) and safety signs around test sites Contingency planning - Emergency Response planning - Proper design of kentledge system - Pre-qualify the subcontractor - Approved Method Statement

- High quality construction inspection and records - Method Statements to ensure safe working methods

- Regular review Instrumentation reading -Permit to remove strut system followed to prevent inappropriate removal of struts - Emergency Response planning - Review SI report and cross check at site - Provide water relief wells when necessary

- Emergency Response planning including Contingency planning - Adopt 3X3 lifting principles. - Only R/S is allowed to give signal to crane operator.

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

Mar-17

Mar-17

Mar-17

Mar-17

Mar-17

Oct-17

Oct-17

Due Date By

Revision G 13 14

7 months

7 months

7 months

7 months

7 months

13 months

13 months

Risk Exposure Period

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Status

Date: 27/04/2017 15 16 17 Remarks

105

105

T309/CNSS

T309/CNSS

003

002

T309/CDSS/105/003

T309/CDSS/105/002

T309/CDSS/105/001

Adjacent Structures or Buildings T309/CNSS 105 001

NA

T309/CDSS/103/001

103

Permanent Works T309/CNSS

012

001

102

T309/CNSS

Construction work nearby to adjacent structures or buildings

Construction work nearby stake holders

Construction work nearby to school

Construction of Permanent Works

Lifting with crane

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

5

- Breakage of lifting chain - Breakage of lifting sling - Failure of brake motor/gear - Failure of sling/chain buckles and hooks - Overloading of carried loads over limited of design capacity - Unauthorized modification of lifting points

Hazard Cause

- Improper securing of material/ equipment/ cages - Overloading of material/ equipment/ cages - Slight tilt in crane '- Sudden movement of crane boom

Excessive ground and building settlement

Damage / excessive settlement to buildings/structures: - Victoria School Access Bridge - 2-storey semi-detached houses at Kee Sun Ave - St. Andrew's Autism Centre - Elliot at The East Coast - Laguna Park Electrical Substation (Block 5000F) - 2-storey semi-detached houses at Elliot Walk - Opera Estate Canal & Culverts Interface with the public.

Stop or delay school operation. Interface with the public.

- Activation criteria and minimum head are not given

- Ineffectiveness of recharge well layout given in the A/E design '- Some recharge well points will not provide effective recharging due to their locations being far from the buildings to be protected - Filter may not be compatible with the existing ground conditions - Pile test and D-wall test

-Long term settlements - Scheduling of work planning

-Unforeseen ground conditions -Excavation works causing unforeseen settlements -Groundwater drawdown

-Proximity of schools has special implications, -Victoria school is boarding school) - Scheduling of work planning

Excessive settlement - Insufficient ground information available for (Victoria School bridge and design canal structures)

Failing of loose material/ equipment/ rebar cages

Crane topple / Hoisted load - Poor crane footage hit crane - Incompetent lifting team - Poor lift plan - Congested work environment

Failure of lifting mechanism

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

7

- Damage to utilities - Damage to property

- Disruption to the site activities during installation of recharge well - Blockage of the filter gravel - Excessive water flow rate provided by the pumping system but little recharging effect

- Claims - Damage to buildings/structures - Complains from the public - Injuring the public

- Damage to buildings/structures - Delays - Claims - Closure of roads - Injuries / fatalities of construction workers and public

-Noise disruption to schools -Pick up and drop off times Damaged - Complains from the public - Injuring the public

- Serviceability issue with the bridge

IV

IV

V

V

III

IV

IV

III

III

I

I

IV

III

I

I

IV

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

I

S

IV

F

C

C

C

C

C

C

B

B

B

Ri

Initial Risk Category Ri

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

Impact

Package 1 8

-Activation criteria and minimum have been designed and indicated (Zone 1 to 3)

- Contractor's consultant has designed the recharging system, modified the configuration - Design of filter gravel has been provided

- Instrumentation / Monitoring - Reduce work inteface with public during peak hours

- Contractor’s Method Statements - instrumentation / monitoring - Real time monitoring - Specification of instrumentation and monitoring requirements by AE consultant - Strengthening and temporary propping when necessary - Additional site investigation

- Contingency planning, inspection and monitoring - Method Statements - Additional site supervision (e.g. traffic marshal) - Reduce work inteface with public during peak hours

- Provision of additional boreholes for bridge and canal design

- Approved PTW (e.g lifting) daily before commencement of work - Lifting Supervisor to ensure correct method of usage - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Avoid loading and unloading near edge of properties or access walkways - Low speed in lifting and lowering of material '- Signaller to communicate with crane operator during lifting and lowering operation - Lifting points to be marked, identified and approved - Approved Lifting plan - Material shall be stacked safely and within stacking limit and load

- Design and COS crane access - No Overloading at all times - Proper maintenance of crane - Only competent lifting team is allowed - Implemet Permit to lift - Include both Max. and Min load radius - Do not conduct lifting in congested work environment. - Provide exclusion zone and Provide warning signs. - Provide sufficient tag lines

- Apply PTW (e.g. lifting) daily before commencement of work - Monthly inspection of lifting mechanisms - Lifting Supervisor to ensure correct method of usage - Colour coding all lifting mechanisms for validity and serviceability levels - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Lifting points to be marked, identified and approved - Approved Lifting Plan

Mitigation Measures

IV

IV

V

V

III

IV

III

III

I

I

IV

III

I

I

V

V

I

S

V

F

C

C

C

C

C

C

C

C

C

Ri

Residual Risk Category Rr

11

- Provide proper recharging system - Provide proper filter gravel - Instrumentation/ Monitoring of settlement - Additional Site investigation

- Emergency Response planning - Provide proper recharging system - Provide proper filter gravel - Instrumentation/ Monitoring of settlement - Additional Site investigation - Control of bentonite pressures

- Perform ground improvements when necessary

-Emergency Response planning including Contingency planning -Instrumentation/monitoring to monitor strut loads. - Instrumentation/ real time monitoring - Sufficient vibration monitors with appropriate trigger levels to be installed. - Provision of recharge wells. -Provide proper recharging system -Provide proper filter gravel

12

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

*Action Owner

JHZH-PM

Risk Owner

JHZH-PM - Proper planning and traffic control - Provide soundproof wall - Close communication with the school and be cognisant of critical times in the school calendar

- Emergency Response planning - Insturmentation and monitoring of settlement - Additional Site investigation when necessary

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

May-20

Oct-17

Oct-17

Oct-17

Due Date By

Revision G 13 14

79 months

79 months

79 months

79 months

79 months

45 months

13 months

13 months

13 months

Risk Exposure Period

C

C

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Open

Open

Status

Date: 27/04/2017 15 16 17 Remarks

T309/ CNSS

105

004

N.A

Traffic Diversion around Victoria School

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

- Congested road leading to Victoria school - Construction activities in front of Victoria school - Heavy machinery stationed along Siglap Link - Heavy traffic from new egress to Marine Parade Road - Pedestrians jaywalking -Inadequate signage and poor traffic control measures -Unsafe traffic layout -Failure to carryout trial trench for UG services -Failure to barricade work area and provide banksman to guide vehicular movement on site -Failure to equip with proper PPE

Risk associated with Traffic Diversion -Unsafe traffic conditions, accident hot spot and vehicles crashing into site -Damaged to UG services -Noise and dust pollution

5 Hazard Cause

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

- Collision of construction and public vehicles - Delays - Claims - Injury to public or construction personnel

Impact

Package 1 7

S II

F IV

C

Ri

Initial Risk Category Ri

8

- Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan '- Guard rail or rigid barrier to be setup and interlocked properly - designated path for access by pedestrians '- Code of Practise of Traffic Control and Work Zone -Approval of temporary traffic diversion layout by TM -Traffic layout and signage to follow TCP -Submit PSR (road) for clearance -Ensure good visibility of signage --Apply permit to dig prior to start work -Conduct RA/ SWP briefing

Mitigation Measures

S II

F IV

C

Ri

Residual Risk Category Rr

11 Risk Owner

JHZH-PM - To provide traffic marshals to direct traffic when necessary - To study provision of temporary traffic lights to faciltate passing of construction and public vehicles smoothly when necessary - Placement of cone or barrier during diversion without reduction in lane width -Desk top study of all utilities and carryout appropriate trial trench -Barricade work area and provide proper signage and warning to motorist and pedestrian. -Lane closure to avoid peak hours, applicable hours is 9:30-16:30 for daytime and 16:30-09:30 for night time closure -Flow chart indicating the flow of instruction enabling the lorry truck to enter the lane closure work area during soil removal or delivery of materials.

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

12

JHZH-PM

*Action Owner

Mar-23

Due Date By

Revision G 13 14

79 months

Risk Exposure Period

C

Target Risk Rating

Open

Status

Date: 27/04/2017 15 16 17

Further improvemen ts will be discuss in PSR roadworks

Remarks

005

Future developments or Addition & Alteration works 112 001 T309/CNSS T309/CDSS/112/001

110

T309/CDSS/110/005

N.A

T309/CNSS

109

Existing Conditions T309/CNSS

004

T309/CDSS/106/003

T309/CDSS/110/004

106

T309/CNSS

003

T309/CDSS/106/002

Interface with Adjacent Contracts T309/CNSS 110 004

106

T309/CNSS

002

T309/CDSS/106/001

T309/CDSS/109/006

106

T309/CNSS

001

006

106

Existing Utilities T309/CNSS

Future developments or Addition & Alteration works

Excavation

Excavation

Excavation for Utility Diversion Works

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

Clashes between railway structures and future underground infrastructure works and/or future above ground developments

Interfacing with adjacent contracts

Incompatible Interfacing with adjacent contracts

Seawall obstruction

Limited Work Areas

Damage to utilities

Damage to utilities and disruption to services

Damage to submarine cable

Hazard

4

5 Hazard Cause

- Injury or fatalities of public and construction workers Unplanned excavation -Insufficient marking on site -Failure to conduct detection test

- Damage to the equipment used - Deep foundation and diaphragm wall are not constructed properly

- Unforeseen higher than designed surcharge

- Damage to utilities - Damage to road surfaces - Damage to property

-Proposals for future underground infrastructure - Incompatible construction techniques and developments in direct conflict with alignment and stations - Delay of works - Unaware of future infrastructure and developments proposals

Effect of T310 TBM tunnels on D-Walls subway - Excessive ground movement near Entrance C - Movement to adjacent structures

Unappropriate or non-workable connection - Excessive ground movement design at interface of bored tunnels and station - Movement to adjacent structures end walls - Groundwater drawdown - Waterproofing problem and associated repairs

Abandon seawall

- Work areas too restricted or efficient workings - Schedule delays - Work areas require significant temporary - Unsafe environment for construction works for their establishment personnel traffic congestion

-Diversion and support of utilities across excavation: - Water pipe - Power Grid cables - SP Telecom cables - Starhub cables

6 Impact

Disturbance to public

-Non coordinated inter-contract utility diversion, - Delay - Remote disruption -Unforeseen obstructions - Missing information from utilities agencies - Insufficient trial trenches

Insufficient information about cable location

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Package 1

F

V

V

V

V

IV

II

II

I

I

IV

III

I

V

III

III

I

S

III

V

7

C

C

C

C

D

C

C

C

C

Ri

Initial Risk Category Ri

8

- PE to ensure surcharge level to within acceptable loading

- Contractor to review Development Interface Report in detail - Coordination meetings between interfacing designers - Coordination between all parties (Client, Contractor, designers)

- Coordination meetings between interfacing contractors and designers to be managed by Contractors - Construction Interface report by Contractor - Coordination between all parties (Client, Contractor, Designers)

- Coordination meetings between interfacing contractors - Construction Interface report by Contractor - Coordination between all parties (Client, Contractor, Designers) - Specifying waterproofing details @ interface

- Additional trial trench and site investigation

- Buidling temporary decking for efficient road/land use - Detailed SHE procedure to enforce safety

- Ongoing co-ordination with relevant utility companies - Contractor's Method Statement - Approved NCE - Pre-qualify Contractors - Apply PTW daily before commencement of work -Thorough study of utilities drawings -Cable detections by qualified LCDW -Provide clear utilities marking on site -Provide A3 size drawing of utility plan -Apply permit to dig -Barricade work area while trenching -Contact relevant utility agency for any presence of unidentified utility -Always treat utility as `live’ if encountered -Only manual digging allowed for trial trench -Full time supervision during trial trench -No mechanical excavation within 3 meters from live utilities. - Only manual excavation allowed for trial trench digging. - Brief utilities plan in language understood by the workmen.

- Method Statements - Additional site investigation - Approved NCE

- To divert submarine cable away from the station box

Mitigation Measures

V

V

V

V

IV

II

II

I

I

IV

III

I

V

IV

III

I

S

IV

V

F

C

C

C

C

D

C

C

C

C

Ri

Residual Risk Category Rr

11

12

- No stockpiling

- Close coordination with related parties

- Instrumentation and monitoring - Close coordination

- Emergency Response planning e.g. grouting - Methods Statement - Close coordination

- Cross check at site - Laise with related authority about the information of seawall

- Efficient site utilization plan for each different working stage - Hire a professional road safety review learn and checking when necessary

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

-Utility cable detection and trial trench should be JHZH-PM carried out to identify the alignment -Diversion out of the structure footprint -Emergency Response planning including Contingency planning -Close communication with utilities agencies -Cable detection -Properly mark the location of utilities and briefing site staffs, workers and sub-contractors -If unclear with the finding of services after reaching the 2m limit, conduct further detection to determine the presence of any services below. -Dimensions and depth of Trial Trenches recorded by Project Survey Team for As Build information Photo records of trial trench including any utility discovered are recorded

JHZH-PM

JHZH-PM

-Design protective measures and temporary support scheme for utilities across excavation -Close communication with inter-contract and utilities agencies -Identify clear markers for utilities locations lines and brief staffs, workers and subcontractors -Cable detection -Emergency Response planning including Contingency planning

JHZH-PM

*Action Owner

JHZH-PM

Risk Owner

- Divert submarine cable away from the station JHZH-PM box and identify the clearly marker

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

May-20

May-20

May-20

May-20

Jan-17

Oct-17

Oct-17

Oct-17

Oct-17

Due Date By

Revision G 13 14

45 months

45 months

45 months

45 months

5 months

13 months

13 months

13 months

13 months

Risk Exposure Period

C

C

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Open

Open

Status

Date: 27/04/2017 15 16 17 Remarks

001

002

Ground Improvements T309/CNSS 118

118

121

T309/CNSS

Fire and Explosions T309/CNSS

001

009

Construction Methodology T309/CNSS 117

T309/CDSS/121/001

T309/CDSS/118/002

T309/CDSS/118/001

T309/CDSS/117/009

Construction works involving flammable or explosive materials

Construction works for ERSS or permanent walls

Jet grouting

Lifting with crane

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

5

Inappropriate jet grouting methods

-Overloading of lifting equipment -Failure to observe safe work procedures -- Instability of working platform. - Failure of loose material equipment/ rebar cages - Lack of communication - Inadequate supervision and control - Unplanned and poor control of crane movement - Substandard lift plan

Hazard Cause

Fire or explosion during construction

-Encounter flammable materials - Breakage of buried services - Ignition of methane from peat layers - Contaminant gas - War relics/unexploded ordnances - Heavy vehicles carrying flammable materials may be driven into the construction site

Excessive deflection of Insufficient ground improvement / treatment ERSS or permanent walls works

Ground improvement failure

●Crane collapse or failure ●Toppling of crane ●Crane hit surrounding structures, eg silo ●Hoisted material hit crane

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

- Injury or fatality of public or construction workers - Damage to existing structures and services

- Flooding of excavation - Collapse of temporary works and adjacent structures - Injury of public or construction personnel - Disruption of essential services - Delays - Claims

- Collapse of ground - Injury or fatality of construction workers and public - Waterproofing problems and associated repair - Damage to buildings - Delay of works - Movements of adjacent structures

-Injury to site staff -Delay to construction -Damage to property

Impact

Package 1

IV

F

V

V

V

7

I

II

II

II

S

C

C

C

C

Ri

Initial Risk Category Ri

8

- Provision of appropriate plant - additional site investigation and geophysics when necessary - Gather knowledge from people with relevant experience - Apply PTW (e.g hot works) daily before commencement of work - Safety Datasheet and Warning signs and Emergency contacts on display - Reporting to Safety and Security Department

- Contractor to produce robust Design - Method Statements to ensure safe working methods - Robust ERSS Design - instrumentation / monitoring e.g. LBs to monitor building movement, LGs for ground movement and IW or XYZ for ERSS.

- Contractor to produce robust design - Jet grouting trials - Specifying waterproofing details @ interface - Instrumentation / Monitoring e.g. LBs to monitor building movement, LGs for ground movement and IW or XYZ for ERSS. - Additional site investigation and geophysics

- Provide support plates for firm support - Apply PTW (e.g. lifting) daily before commencement of work - Full extension of outrigger prior to lifting - Approved Lifting Permit - No workers shall be allowed to stand below suspended loads - Lifting Supervisor to ensure correct method of usage - Approved lifting plan (e.g. full extension of outrigger, approved and proper use of slings) - Lifting points to be marked, identified and approved -Safety zone established -Tag line with coloured flag to be installed along hoarding to warn operator from crossing the line when turning during lifting -Tag line with coloured flag to be installed at the top of bentonite tank to warn crane operator and signal man to guide operator during crane movement. -Bentonite tanks near to Dwall will only be erected after the completion of Dwall. -To include min load radius in lift plan.

Mitigation Measures

V

V

V

V

F

I

II

II

II

S

C

C

C

C

Ri

Residual Risk Category Rr

11 Risk Owner

- Proper and independent flammable materials storage and management - Emergency Response Planning including Contingency planning e.g. quick evacuation route - Permit to carry hazardous material

- Provide efficient geometric design and the road level to mitigate flooding - Witness the instrumentation reading - Regular review and analyse instrumentation reading - Emergency Response planning include Contingency planning, inspection and monitoring

JHZH-PM

JHZH-PM

- High quality construction records and material JHZH-PM testing - Methods statement - Pre-qualify contractors - Regular review instrumentation reading of inclinometers and ground settlement markers in trial test and feedback main works - Emergency Response Planning including Contingency planning e.g. stop all excavation, ensure safe escape route for workers, additional temporary struts.

JHZH-PM - Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Reminder in tool box meeting - Lifting zone to be barricaded before works commence -Provide adequate hardstanding /firm working platform -Put in place the lifting permit system and display the relevant details on site. -Ensure no overloading of crane -Signaler to communicate with crane operator -Lift load by 300mm, hold for 3 seconds, all personnel 3m away -Approved lifting plan, reviewed by LE and approved by PM -Lifting operation supervised by lifting supervisor -Banksmen to guide crawler crane movement, ensuring no tracking over drain, trench or uneven ground. -Lifting points to be identified and approved -Low speed in lifting and lowering -Material shall be stacked safely and within stacking limit and load -Authorization of all machineries movement from point to point -Establish a permit to move system for heavy machineries -A lockout /tagout system during maintenance and breakdown period of mchineries -Maincon to control all machineries movement on site with daily discussion during coordination meeting -Setting up a security management plan that involved site security to be aware of the delivery of materials and ensuring no material delivery during lunch time and peak hour

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

12

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

*Action Owner

Mar-23

Jan-18

Jul-17

May-20

Due Date By

Revision G 13 14

79 months

16 months

10 months

45 months

Risk Exposure Period

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Status

Date: 27/04/2017 15 16 17 Remarks

122

999

999

999

999

999

999

999

Flooding T309/CNSS

Other Hazards T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

007

006

005

004

003

002

001

002

N.A

T309/CDSS/999/006

T309/CDSS/999/005

T309/CDSS/999/004

T309/CDSS/999/003

T309/CDSS/999/002

T309/CDSS/999/001

T309/CDSS/122/001

4

5 Hazard Cause

Cleaning

Setting up of Noise Barrier

Traffic Diversion

6

Damage to construction works

-Occurrence of a natural disaster during construction - Flooding - Heavy rainfall causing significant ground water table rise

- Construction activities require frequent transport movements - Works at site with long working hours for 7 days a week

Use of high ultra water jet

Noise Barrier and foundation

-Pipe leakage and burst -Loose connection -Lose control of hose

-Construction works in close proximity to the public and existing housing -Excessive noise due to construction

Movement of heavy -Spoil removed to designated location remote vehicles causing disruption from site to traffic movement

F

- Injury to public or construction personnel

- Injury to public or construction personnel - Disruption of essential services - Negative PR - Delays - Claims

- Delay and accidents, - ECM issues, - Mosquito breeding, - Security problems

IV

II

III

III

III

V

IV

IV

I

V

- Flooding of excavation - Collapse of temporary works and adjacent structures - Injury or fatality of public or construction personnel - Disruption of essential services - Delays - Claims

II

III

I

S

II

IV

IV

V

7

C

D

C

D

C

C

C

C

C

Ri

Initial Risk Category Ri

IV

-Environmental pollution

Package 1 8

- Assign two trained hydro jetting operators. - Rotate shift every alternate hours - Provide safety warning signage to keep other works clear from work area - Provide safety access to washing bay

- Method Statements - additional site investigation - Provision of Noise barrier - Monitoring of Noise - Noise control plan - Engage community regularly and gather feedback

- Method Statements -Additional traffic management

- Method Statements - additional site supervision - ECM Plan

- Robust ERSS design including flood barriers when necessary - Temporary groundwater controls and pumps within excavation - Specifying water proofing details @ interface

- Design and approved traffic diversions - Minimise traffic around construction sites - Use of barrier and/or gate guards for exit/ entrances to site

- Design and approved traffic diversions - Clear and good signages - Minimise traffic around construction sites

- Contingency planning, e.g. additional noise barriers, inspection and monitoring - Method Statements to ensure safe working methods - Installation of noise barriers - Noise level monitoring - Engaging community for feedback '- Noise, dust control plan

- Method Statements - Additional site investigation -Confirmation with LTA on any specific flood protection measures required during construction

Mitigation Measures

V

V

IV

II

III

III

IV

I

V

IV

II

II

III

I

S

V

V

V

V

F

C

D

C

D

C

C

C

D

C

Ri

Residual Risk Category Rr

11 Risk Owner

JHZH-PM

12

JHZH-PM

JHZH-PM

- Assign safety supervisor when possible at work place to ensure operation is safe - Barricade work area to prevent unauthorized access and display warning signage.

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM - To provide traffic marshals to direct traffic when necessary - To study provision of temporary traffic lights to faciltate passing of construction and public vehicles smoothly -Designated haul routes -Contingency planning, inspection and monitoring - Placement of cone or barrier during diversion without reduction in lane width - Minimize loud noise activity during evening and weekends - Monitor noise meters at designated intervals - Contingency planning, inspection and monitoring

JHZH-PM

JHZH-PM - Install additional EC measures (e.g. silt fences, nets) when necessary '- Regular inspection of site by ECO at affected zones - Contingency planning, inspection and monitoring

- Close communication with related authority - Emergency Response planning including Contingency planning e.g. quick evacuation route - Provide efficient geometric design and the road level to mitigate flooding

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

*Action Owner

JHZH-PM - To provide traffic marshals to direct traffic when necessary - Clearly defined zones for accessible pathways and restricted areas - Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan - Guard rail or rigid barrier to be setup and interlocked properly - Code of Practise of Traffic Control and Work Zone - Placement of cone or barrier during diversion without reduction in lane width

JHZH-PM - To provide traffic marshals to direct traffic when necessary - Clearly defined zones for accessible pathways and restricted areas - Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan - Guard rail or rigid barrier to be setup and interlocked properly - Code of Practise of Traffic Control and Work Zone - Placement of cone or barrier during diversion without reduction in lane width

- Vibration control plan - Vibration monitoring

JHZH-PM - Provide efficient geometric design and the road level to mitigate flooding -Awareness of climatic conditions -Regular monitor of water level in Opera estate Canal -Emergency Response planning including Contingency planning

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

- Complaint from nearby occupants - Complaint from LTA - Working time may be reduced with delay to programme

-Traffic congestion due to minimum diversions, - Injury to public or construction personnel drivers seeking alternative routes - Damage to temporary or permanent works

Road vehicles entering construction site / excavations

-Traffic congestion - Unauthorized entry of personnel to site

-Construction works in close proximity to the public -Excessive noise due to construction -Excessive noise due to bored and barette pile testing

- Injury to public or construction personnel - Disruption of essential services - Negative PR - Delays - Claims

-Interrupted construction, -Delays, -Environmental pollution

Impact

Noise, dust and vibration

Flooding from the Opera -Damage the canal or foundation during Estate Canal at Siglap Link construction, -Extreme flooding event; -Tidal fluctuation -Structural problem of the canal

Hazard

Discharge into Canal from -Heavy rain construction - Insufficient control on site -Surface run off, construction materials Construction Works (bentonite, concrete, grout, near Drains and Canal maintenance/cleaning facilities)

Construction Works near Drains and Canal

Traffic Diversion

Construction Works near Residental area

Construction works near Opera East Canal

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Mar-23

Mar-20

Mar-23

Mar-20

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

Due Date By

Revision G 13 14

79 months

45 months

79 months

45 months

79 months

79 months

79 months

79 months

79 months

Risk Exposure Period

C

C

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Open

Open

Status

Date: 27/04/2017 15 16 17 Remarks

999

999

999

999

999

999

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

Site set up T309/CNSS

013

012

011

010

009

008

NA

N.A

N.A

N.A

N.A

N.A

Setting up of Noise Barriers

Recahrge well work

Lifting with Excavator (Pick and Carry)

Traffic Diversion

Traffic Diversion

Removal of sludge

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

MEWP topple

Hit by fallen object

Fall from height

Noise Barrier structural failure

Water pipe. Power grid cables. Telecom cables. High tension cables.

6

- Collapse of temporary works - Excessive movement / Collapse of adjacent structures - Injury or fatalities of public and construction workers

-Damage of machinery -Injury of worker -Damage of materials

-Damage of machinery -Injury of worker -Damage of materials

- Traffic jams hindering construction vehicles - Bottlenecks hindering traffic speed - Crossed traffic and pedestrian circulation paths - injury to public and/or construction work

- Traffic jams hindering construction vehicles - Bottlenecks hindering traffic speed - Crossed traffic and pedestrian circulation paths - injury to public and/or construction work

'- Injury to public or construction personnel - Contaminate soil, groundwater and surface water

Impact

-Failure to provide fall protection provision - Failure to provide control - Poor footage - Over loading of MEWP

-Damage to own and public properties (Claims) - Injury or fatalities of public and construction workers

- Collapse of temporary works - Incorrect information on adjacent structures - Not identifying the behaviour and response of - Damage to own and public properties (Claims) - Injury or fatalities of public and construction the ground and adjacent structures workers

-Flawed design of temporary works - Inappropriate use / misinterpretation of design codes - Lack of understanding of design software and output - Temporary works design is incompatible with adjacent structures

-Unplanned Drilling. - Insufficient marking on site. - Failure to conduct detection test.

-Uneven ground - Unauthorised lifting - Improper rigging -Overloading -Inexperience operator

-“A’ frame topple - Injury to public - Fingers / hand caught in rotating parts

- Change to road condition due to delivering material to site

- Change to road condition due to construction work, poor line of sight - Changed traffic condition causes confusion to road users - Improper/ unclear signages - Improper/ unclear separation of pedestrians paths and work site ingress/ egress points - Pedestrians jaywalking

-Pipe leakage and burst -Loose connection

-Uneven ground - Unauthorised lifting - Improper rigging -Overloading -Inexperience operator

-Damaged to :

5 Hazard Cause

-Toppling of excavator - Falling of load/ material

Risk associated with Traffic Diversion

Risk associated with Traffic Diversion

Sludge spill

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Package 1 7

II

II

IV

IV

II

II

II

II

II

IV

IV

IV

IV

IV

II

II

IV

S

F IV

C

C

C

B

B

B

C

C

C

Ri

Initial Risk Category Ri

8

- Provision of Fall Protection Plan. - Establish PTW-Height system. - Provide proper access. - Provide adequate work platform. - Licensed MEWP operator. - Familiarisation briefing prior appointment.

- Perform further structural or geotechnical investigations e.g. coring, trial trenching - Apply PTW (e.g. welding) daily before commencement of work - Certified welder

- Sensitivity of design input parameters - Pre-qualify contractor - Apply PTW (e.g. welding) daily before commencement of work - Certified welder

-Thorough study of utilities drawings. - Cable detections by qualified LCDW - Provide clear utilities marking on site - Provide A3 size drawing of utility plan - Apply permit to dig and implement “checklist for working near utility” - Barricade work area while trenching

- Ensure work assess is planned. - Ensure adequate access for work mobilisation and public access. - Only competent lifting crew is allowed to involved in mobilisation. - PTW-Lifting approved prior unloading. - Provide proper exclusion zone to segregate work and public. - Provide warning signs.

●The excavator designed for pick and carry operations must have load chart stating clearly the limitattions for picks and carry operation ●Tag line shall be used during operation ● Ensure the route of travel is firm and level ●Lifting supervisor to ensure the load is firmly secured and tied ●Benchman to guide excavator during the pick and carry operation

- Design stages of traffic diversion to allow construction to be carried out section by section - Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan - Safety barrier to be setup at designated storage zones - Proper signages display at prominent locations - Code of Practise of Traffic Control and Work Zone - designated path for access by pedestrians - Control unauthorized entry of personnel into loading/unloading zone during material delivery

- Design stages of traffic diversion to allow construction to be carried out section by section - Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan - Guard rail or rigid barrier to be setup and interlocked properly Proper signages display at prominent locations - Code of Practise of Traffic Control and Work Zone

- Competent staff - Provide safety warning signage to keep other works clear from work area - Provide safety access to treatment plant - Permit for handling of sludge - Provide emergency contact no.

Mitigation Measures

II

II

V

V

II

II

II

II

II

V

V

V

V

V

II

II

V

V

S

F

C

C

C

C

C

C

C

C

C

Ri

Residual Risk Category Rr

11

JHZH-PM

Risk Owner

JHZH-PM

12

JHZH-PM

JHZH-PM

- Strengthening of noise barrier when necessary JHZH-PM - Additional site investigations and localized ground improvement when necessary - Emergency Response planning including Contingency planning e.g. stop all excavation, ensure safe escape route for workers, additional temporary struts. - Approved Method Statement

-Enveloped MEWP work platform with scaffold JHZH-PM netting to contain material. Limit max. 2 person on MEWP. Max. weight 120kg. Firm and compacted ground for MEWP access. Provide adequate exclusion zone and signage. Provide banksman to ensure no authorised entry in to work zone.

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

*Action Owner

JHZH-PM - Engage experienced and competent consultant to perform the design - Engage experienced and competent contractor - Emergency Response planning including Contingency planning e.g. stop all excavation, ensure safe escape route for workers, additional temporary struts. - Approved Method Statement

-Contact relevant utility agency for any presence JHZH-PM of unidentified utility Always treat utility as `live’ if encountered Only manual digging allowed for trial trench Full time supervision during trial trench

- Provide blinker lights to alert night motorist and /or pedestrian. - Ensure footage is firm and level at all times. - Never drag load. Lift vertically.

-AE to examine the lifting capacity of excavator JHZH-PM and issued the certification for the lifting. -Pick and carry operation is guided in SS536 : 2008

JHZH-PM - To provide traffic marshals to direct traffic when necessary - To study provision of temporary traffic lights to faciltate passing of construction and public vehicles smoothly - Placement of cone or barrier during diversion without reduction in lane width

JHZH-PM - To provide traffic marshals to direct traffic when necessary - To study provision of temporary traffic lights to faciltate passing of construction and public vehicles smoothly - designated path for access by pedestrians - Placement of cone or barrier during diversion without reduction in lane width

- Contain and handle spillage (e.g. excavate spill site and treat with dry sand, temporary diking) immediately - Contact additional emergency services when necessary

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

Mar-23

Mar-23

Mar-23

May-23

May-23

Mar-23

Mar-23

Mar-23

May-20

Due Date By

Revision G 13 14

79 months

79 months

79 months

79 months

79 months

79 months

79 months

79 months

45 months

Risk Exposure Period

C

C

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Open

Open

Status

Date: 27/04/2017 15 16 17 Remarks

T309/CNSS

999

014

NA

4

Hazard

5

6

Old machinery and poor maintenance causing disturbance to nearby resident

Installation of sheet piles Noise pollution (foundation support for sound barrier)

Installation of sheet piles Accidental dislodgement of -Carelessness and inexperience operator. (foundation support for sheet pile during driving - Faulty vibro hammer sound barrier)

Structure failure of machinery

Installation of sheet Using of poor condition piles (foundation support for machinery sound barrier)

-Serious injury to worker and property. -Stop work causing delay

-Disturbance to neighbouring resident -Hearing injury to workers

-Low productivity Job delay and behind schedule -Cost implication

-Serious injury to worker and property. -Stop work causing delay

-Toppling of machinery resulting in damage to property. -Injury to surrounding people.

Installation of sheet piles Poor ground condition (foundation support for sound barrier)

-Damage to underground services -Disruption to stakeholders -Penalty charges by authority -Stop work order by authority -Delay to work schedule

Impact

-Serious injury to worker and property. -Stop work causing delay -Damage to machineries

Location of utilities not reflected in utility drawing

Hazard Cause

Installation of sheet Collision of machinery and piles Constraint of work area (foundation support for site people. sound barrier)

Installation of sheet piles Damage to utilities (foundation support for sound barrier)

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Package 1

-

IV

IV

IV

IV

IV

IV

7

F

I

II

II

I

I

II

S

B

C

C

B

B

C

Ri

Initial Risk Category Ri

8

I

-Additional sling tied to sheetpile and machinery as extra protection in case grabber gives way V -Ensure sheetpile is clamped tightly between the grabber jaws before hoisting up vertically for installation

II

I

I

II

II

V

V

V

F

S

C

C

C

C

C

C

Ri

Residual Risk Category Rr

-Installed sound barrier. -Used of silent piler. V -Refrain from working at night and weekend/PH

-Machine to be inspected and certified by AE. -Regular monthly maintenance of machineries

-Access to be laid with hardcore and compacted. -Steelplate to be laid on top of hardcore. -Movement of machinery must be guided by benchemen

-Work zone to be barricaded to prevent unauthorized entry -Used of tag line to control swaying of load - Employed skilled operator and experienced lifting team

-Carry out cable detection and trial trench along the path of sheet piles. V -Apply permit to dig prior to work start.

Mitigation Measures

Daily pre operation check on grabber by operator before start of work

Regular maintenance regime in place

LOTO system applied during maintenance period

-Ground preparation completed with the issuance of COS from PE -Ensure no overloading of machinery (Load kept at 75% of SWL

Apply for permit to move for machinery movement from point to point

Cable detection by LEW

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

11

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

Risk Owner

12

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

*Action Owner

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

Due Date By

Revision G 13 14

79 months

79 months

79 months

79 months

79 months

79 months

Risk Exposure Period

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Status

Date: 27/04/2017 15 16 17 Remarks

999

999

999

999

T309/CNSS

Vector Management T309/CNSS

T309/CNSS

Mobilization T309/CNSS

018

017

016

015

NA

NA

NA

NA

Traffic Diversion

Workers working on site

Setting up of Hoarding

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

5 Hazard Cause

Risk associated with Traffic Diversion -Unsafe traffic conditions, accident hot spot and vehicles crashing into site -Damaged to UG services -Noise and dust pollution

Transmission of Dengue and Zika

Mosquito bites on construction/ public personnel

6

- Collapse of temporary works - Excessive movement / Collapse of adjacent structures - Injury or fatalities of public and construction workers

Impact

- Transfer (delivery and lifting) material, plant and manpower -Inadequate signage and poor traffic control measures -Unsafe traffic layout -Failure to carryout trial trench for UG services -Failure to barricade work area and provide banksman to guide vehicular movement on site -Failure to equip with proper PPE

- Mosquito breeding - Mosquito bites

- Mosquito breeding - Mosquito bites

- Traffic jam - Injury to public or construction personnel - Claims - Delays

- Injury or fatality of public or construction personnel - Claims - Delays

- Injury to public or construction personnel - Claims - Delays

- Collapse of temporary works - Incorrect information on adjacent structures - Not identifying the behaviour and response of - Damage to own and public properties (Claims) the ground and adjacent structures

Hoarding structural failure -Flawed design of temporary works - Inappropriate use / misinterpretation of design codes - Lack of understanding of design software and output - Temporary works design is incompatible with adjacent structures

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Package 1 7

IV

IV

IV

IV

IV

F

II

I

I

II

II

S

C

B

B

C

C

Ri

Initial Risk Category Ri

8

- Code of Practise of Traffic Control and Work Zone - Use of barrier and/or gate guards for exit/entrances to site -Approval of temporary traffic diversion layout by TM -Traffic layout and signage to follow TCP -Submit PSR (road) for clearance -Ensure good visibility of signage --Apply permit to dig prior to start work -Conduct RA/ SWP briefing -Desk top study of all utilities and carryout appropriate trial trench -Barricade work area and provide proper signage and warning to motorist and pedestrian. -Lane closure to avoid peak hours, applicable hours is 9:30-16:30 for daytime and 16:30-09:30 for night time closure

- Pest control '- Emergency Response planning - Vector control management - Additional supervision - Oiling in stagnant water and other respective areas - Provision of insect repellents to site staff

- Pest control - Emergency Response planning - Vector control Management - Additional supervision - Oiling in stagnant water and other respective areas - Provision of insect repellents to site staff

- Perform further structural or geotechnical investigations e.g. coring, trial trenching

- Sensitivity of design input parameters - Engage experienced and competent consultant to do the design - Engage experienced and competent contractor - Pre-qualify contractor

Mitigation Measures

IV

V

V

V

V

F

II

I

I

II

II

S

C

C

C

C

C

Ri

Residual Risk Category Rr

11 Risk Owner

JHZH-PM

JHZH-PM

JHZH-PM - Properly traffic control and signages with qualified traffic marshal - Clearly defined zones for accessible pathways and restricted areas - Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan - Emergency Response planning including Contingency planning, inspection and monitoring - Lifting zone to be barricaded before works commence - Placement of cone or barrier during diversion without reduction in lane width -Flow chart indicating the flow of instruction enabling the lorry truck to enter the lane closure work area during soil removal or delivery of materials.

- Regular inspection of site to identify and eliminate breeding sites - Misting

- Regular inspection of site to identify and eliminate breeding sites - Misting

JHZH-PM - Strengthening of hoarding when necessary - Additional site investigations and localized ground improvement when necessary - Emergency Response planning including Contingency planning e.g. stop all excavation, ensure safe escape route for workers, additional temporary struts.

JHZH-PM - Engage experienced and competent consultant to perform the design - Engage experienced and competent contractor - Emergency Response planning including Contingency planning e.g. stop all excavation, ensure safe escape route for workers, additional temporary struts.

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

12

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

*Action Owner

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

Due Date By

Revision G 13 14

79 months

79 months

79 months

79 months

79 months

Risk Exposure Period

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Status

Date: 27/04/2017 15 16 17 Remarks

999

T309/CNSS

020

019

N.A

NA

Lifting with crane

Lifting with crane

4

5

- Breakage of lifting chain - Breakage of lifting sling - Failure of brake motor/gear - Failure of sling/chain buckles and hooks - Overloading of carried loads over limited of design capacity - Unauthorized modification of lifting points

Hazard Cause

- Improper securing of material/ equipment - Overloading of material/ equipment - Slight tilt in crane '- Sudden movement of crane boom

Sharp edge material being - Site personnel cut by sharp material during lifted/ lowered/ handled handling

Failing of loose material/ equipment

Crane topple / Hoisted load - Poor crane footage hit crane - Incompetent lifting team - Poor lift plan - Congested work environment

Failure of lifting mechanism

Hazard

Note * - Action Owner will be reassigned from PM to Engineer-in-Charge when respective Engineer-in Charge is established

999

T309/CNSS

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

7

- Injury and fatality to construction personnel - Delays - Claims

I

II

IV

IV

I

IV

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

I

S

IV

F

C

B

B

B

Ri

Initial Risk Category Ri

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

Impact

Package 1 8

- Store all sharp material into material cages when possible - Pack/ organize sharp material - Use of PPE (e.g appropriate safety gloves, long sleeves, helmet and safety boots and glasses)

- Approved PTW (e.g lifting) daily before commencement of work - Lifting Supervisor to ensure correct method of usage - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Avoid loading and unloading near edge of properties or access walkways - Low speed in lifting and lowering of material '- Signaller to communicate with crane operator during lifting and lowering operation - Lifting points to be marked, identified and approved - Approved Lifting plan - Material shall be stacked safely and within stacking limit and load

- Design and COS crane access - No Overloading at all times - Proper mainyenance of crane - Only competent lifting team is allowed - Implemet Permit to lift - Include both Max. and Min load radius - Do not conduct lifting in congested work environment. - Provide exclusion zone and Provide warning signs. - Provide sufficient tag lines

- Apply PTW (e.g. lifting) daily before commencement of work - Monthly inspection of lifting mechanisms - Lifting Supervisor to ensure correct method of usage - Colour coding all lifting mechanisms for validity and serviceability levels - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Lifting points to be identified and approved - Approved Lifting Plan

Mitigation Measures

I

II

IV

I

V

V

I

S

V

F

C

C

C

C

Ri

Residual Risk Category Rr

11

12

JHZH-PM

- '- Identify sharp material and dipose (e.g. nails, JHZH-PM broken glasses) - Wrap sharp edges when possible

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

*Action Owner

JHZH-PM

Risk Owner

JHZH-PM

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

Oct-17

Mar-23

Oct-17

Mar-23

Due Date By

Revision G 13 14

13 months

79 months

13 months

79 months

Risk Exposure Period

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Status

Date: 27/04/2017 15 16 17 Remarks

Minutes Title: 3 months look ahead Risk Register Workshop No 11 Date: 13 Apr 2017 Time: 10.30am-12.30pm Held at: LTA level 2 meeting room

Chaired by: Jong/ Peter Minuted by: Jong Distribution date: 27 Apr 17

Attendees list See attached

Apologies list

Page 1 of 3

Minutes ITEM

MATTERS DISCUSSED

1.0

Introduction

ACTION

The complete flow of the process will be demonstrated via a short slide presentation

Info

Jong introduced the three months' activities from Apr-Jun 17 at the five working zones.

2.0

2.1

Slide presentation on activities at Entrance A

LTA commented to note on the sealing between Canal and Diverted Drain and any debris resulted from excavation to be cleared from the drain.

2.2

Jong/ Peter

JHZH

JHZH LTA commented to look into tree removal when grabbing D-wall at Entrance A

3.0

Slide presentation on activities at Cooling Tower

Jong/ Peter

3.1

JHZH commented that CCTV will be installed to view trucks loading soil in and out of site and possibly to monitor unsafe acts when Working at Height

INFO

4.0

Slide presentation on activities at Entrance D

Jong/ Peter

4.1

LTA commented to manage the public movement within Entrance D and regularly update the school on changes in construction sequence and the implementation of safety measures

5.0

Any Other Matters:

5.1

LTA commented to inform Nparks on 17th Apr the start of Traffic Diversion Stage 1C.

5.2

5.3

LTA commented that 3 months look ahead shall focus only on major risk. The presentation is too long. LTA commented that concrete pump supplier should inspect and use the correct type/length of pipe when pumping concrete.

Page 2 of 3

JHZH

INFO JHZH

Minutes ITEM

MATTERS DISCUSSED

6.0

Next Meeting

ACTION

The next meeting will be scheduled on 27 Apr 17 @ 10am

Page 3 of 3

All / Info

18th May 2017

Jong/ Peter Nugent/ Tommy

3 Months Programme Look ahead Risk and Mitigation

Construction of Siglap Station Thomson‐East Coast Line

Contract T309

2) To identify the major risk hazards and elaborate the mitigation measures in this  workshop

1) To identify the major works activities for the three months, May 2017 – Jul 2017

Objectives of this workshop:

Hoarding Installation Noise Barrier installation Box culvert drain works Utility Corridor Installation Road Works

Entrance C

Guide Wall & D‐Wall construction (L‐shape‐Dwall lifting)

3

Recharge Well Installation

Guide Wall & D‐Wall construction

Cooling Tower

Road Works ‐Siglap Link Drain works‐ Siglap Link Noise Panel installation Inside the Victoria School Noise Panel installation near to Laguna Park Hoarding Installation Guide Wall & D‐Wall construction

Drain connection to canal work at Keesun Avenue Noise Panel installation above Drain Noise Panel installation Siglap Linear Park Guide Wall & D‐Wall construction

Entrance B

Entrance D

Entrance A

Upcoming Works May 17 – Jul 17

Works at Ent. B

Entrance B

D‐Wall construction (L‐shape panel)

Entrance B

Side View

Ground

“L” shaped D‐wall panel

Plan View

6.5m

1) “L” shaped D‐wall panel installation – Risk mitigation

5

Normal D‐wall panel

Hazard  Cause

• •

•

•

Loose  • material on D‐ • wall panel •

6

Designed and COS crane access. Approved Permit to Lift. Approved lift plan. Valid and adequate lift gears for taking weight  of D‐wall panel. Provide adequate tag lines. Identify proper hooking point for turning D‐ wall. Only one LS to control tandem lift. Standing supervision by LE. Ensure lifting activities not carried out in  congested work area. Ensure no loose material on D wall panel prior  lifting. Provide exclusion zone and warning sign to  prevent unauthorised entry. Tandem lift to be carried out during day shift. No obstruction of LS/CO view at all times.

Mitigation Measure

Unplanned lift • • • Workers hit by  Over loading  • fallen objects  due to poor from D –wall coordination  • between  LS •

Risk 

Tandem lift  Crane collapse work

Activity

1) “L” shaped D‐wall panel installation – Risk mitigation

‐ ‐

‐

‐

JV Superintendent – Peter HSL LS Ahmed Sufi

HSL LS Ahmed Sufi

HSL LS Ahmed Sufi

JV Lift Engineer Killi JV Lift Engineer killi JV Superintendent – Peter

HSL LS Ahmed Sufi JV Engineer Desi

‐ ‐ ‐ ‐ ‐

LV lift Engineer Killi JV Project Manager ‐ Frank JV Project Manager ‐ Frank HSL LS Ahmed Sufi

‐ ‐ ‐ ‐

Action Owner

Hand finger  injuries /  Amputation

Stitching   D‐wall

Workers fall  into d‐wall  trench

Risk 

Activity

‐

‐ ‐

7

Designed stopper for resting D wall cage All personnel to cleared at least 3 meters away  during lowering of stitched D‐wall. Do not start stitching rebar cage until rebar  cage is fully rested on stopper. Always keep hand away from line of fire. Provide proper barricades and warning sign  around D—wall trench.

Mitigation Measure

‐ D‐wall stiches  ‐ tear due to  poor  coordinated  lift

Uncontrolled  movement /  poor  coordinated lift.

Hazard  Cause

1) “L” shaped D‐wall panel installation – Risk mitigation

‐ ‐

‐

‐ ‐

HSL Supervisor – Sohel HSL Supervisor‐ Sohel

HSL Supervisor – Sohel

JV Engineer – Desi HSL Supervisor Sohel

Action Owner

Entrance A Drain Work connection to existing cannel at Keesun Avenue Noise Panel installation above Drain Noise Panel installation Siglap Linear Park Guide Wall & D‐Wall construction

Works at Ent. A

Drain work at Keesun Ave. 

2) “Diverted drain connection to existing cannel – Risk mitigation

2) “Diverted drain connection to existing cannel – Risk mitigation

Risk 

Connection  New diverted  to existing  drain flooded drain

Activity

Back flow from existing  drain due to  high tides

Hazard  Cause

•

•

•

Richee / Technocrete Supervisor‐ Babu/Sayeed Richee Supervisor‐ Babu

‐

JV Engineer – Jessica ‐

‐

JV Engineer – Jessica Richee/ Technocrete Supervisor‐ Babu/Sayeed

‐ ‐

• • Work to be carryout on low tide period. Provide sandbags to block water from entering  work area. No personnel to enter drain when water start  back flowing. No workers allowed inside drain when water is  more than or equal to 10cm deep. Markers to be clearly mark out inside drain.

Action Owner

Mitigation Measure

2) “Diverted drain connection to existing canal – Risk mitigation

Wall cut not  secured

Workers crush  by collapse  wall

Hazard  Cause

Back flow from existing  drain due to  high tides

Risk 

Connection  Flooding of  to existing  diverted drain drain

Activity

•

• •

•

•

• •

JV Engineer – Jessica

Technocrete Supervisor‐ Sayeed Technocrete Supervisor‐ Sayeed

Richee / Technocrete Supervisor‐ Babu/ Sayeed

JV Engineer – Jessica

JV Engineer – Jessica Richee / Technocrete Supervisor‐ Babu/ Sayeed

Action Owner

Work to be carryout on low tide period. ‐ Provide sandbags to block water from entering  ‐ work area. ‐ No personnel to enter drain when water ‐ Wall must be properly secured before cutting  take place.  ‐ MS must be strictly followed. ‐ Never place man near wall especially when  cutting come to the last bit. ‐ Standing supervision by JV Engineer and  ‐ subbies supervisor. ‐

Mitigation Measure

2) “Diverted drain connection to existing cannel – Risk mitigation

Guide wall and D‐wall construction work at Ent. B

Works at Ent. B

D‐wall work

Activity

Crane hit surrounding structures, e.g. silo

Crane Toppling

Risk 

•Load hit onto crane

•Instability of working platform

•Failure of loose material equipment/ rebar cages

Hazard Cause

2) D‐walling lifting work – Risk and Mitigation

‐

•Material shall be stacked safely and within stacking limit and load

‐

‐

• Look into min load radius when hoisting bulky items e.g. rebar cage. •Only R/S can give signal. Trade supervisor cannot involved in lifting work.

HSL R/S Ganesan

‐

•Signaler to communicate with crane operator

HSL LS Ahmed Sufi

HSL SC‐ Omar

HSL LS Ahmed Sufi

HSL Supervisor‐ Sohel HSL LS Ahmed Sufi ‐

•Safety zone established

‐

•Low speed in lifting and lowering

JV Engineer Desi

JV LE Killi

‐

•Approved lifting plan, reviewed by LE and approved by PM

‐

HSL LS Ahmed Sufi

‐

•Lift load by 300mm, stabilized for 3 seconds.

•Lifting points to be identified and approved

Action Owner

Mitigation Measure

D‐wall work

Activity

Crane hit surrounding structures, e.g. silo

crane Toppling

Risk 

HSL supervisor‐ Sohel

‐

•Put in place the lifting permit system and display the relevant details on site.

•Inadequate supervision and control

•Lack of communication

•Banksmen to guide crawler crane movement, ensuring no tracking over drain, trench or uneven ground.

•Lifting operation supervised by lifting supervisor

•Approved lifting plan, reviewed by LE and approved by PM

HSL LS Ahmed Sufi HSL R/S Ganesan

‐

JV PM‐ Frank

‐

‐

HSL supervisor‐ Sohel

JV Superintendent

‐

•Provide adequate hardstanding /firm working platform

‐

Action Owner

Mitigation Measure

•Instability of working platform •Ensure no overloading of crane •Signaler to communicate with crane •Failure of loose material operator equipment/ rebar cages

Hazard Cause

2) D‐walling lifting work – Risk and Mitigation

Preparation of ground access with hard‐core

2) D‐walling lifting work – Risk and Mitigation

Heavy machine on steel plate

PTW –lifting system is established

2) D‐walling lifting work – Risk and Mitigation

Lifting supervisor checking the checklist of operator

Load chart display ensuring no overloading of crane.

2) D‐walling lifting work – Risk and Mitigation

Daily checklist of machinery

Low speed in lifting and lowering

Lifting points to be identified and approved

Approved lifting plan

Lift load by 300mm, hold for 3 seconds

2) D‐walling lifting work – Risk and Mitigation

Safety zone established

Material shall be stacked safely and within stacking limit and load

Approved lifting plan for all heavy lifting on site

2) D‐walling lifting work – Risk and Mitigation

Pre‐start briefing in language understood by workmen prior lifting  work.

2) D‐walling lifting work – Risk and Mitigation

Provide exclusion zone and warning signs

2) D‐walling lifting work – Risk and Mitigation

To include min load radius in lift plan.

LM Machine not up to expectation will tagged “Not Safe for Use”

2) D‐walling lifting work – Risk and Mitigation

End

Minutes Title: Risk Register Workshop No. 14 Date: 18 May 2017 Time: 11.00am-12.00pm Held at: LTA level 2 meeting room

Chaired by: Tommy Lee/ Peter Nugent/ Minuted by: Tommy Lee Distribution date: 22 May 17

Attendees list See attached

Apologies list

Page 1 of 3

Minutes ITEM

MATTERS DISCUSSED

1.0

Introduction

ACTION

Risk Workshop will be on 3 months look ahead presentation with TD1 canal works connection at Entrance A and lifting of L-shape D-wall panel held on 18 May 2017 was submitted. This is the no. 14 workshop held.

Info

The complete flow of the process will be demonstrated via a short slide presentation The project superintendent will provide the necessary information required to mitigate risks on TD1 canal works and L-shape D-wall lifting works. 2.0

Slide presentation on 3 months look ahead activities 2.1

2.2

2.3

2.4

T309P informed JHZH that space between two cranes shall be considered carefully within the site utilization. T309P informed that pictorial safe working procedure can be a more effective way to educate the workers.

JHZH informed that the lifting of the L-shape panel methodology is under discussion and will be finalize in the method statement. T309P informed that the large cage is propped up in other project and for JHZH's consideration. T309P asked on the risk involving traffic diversion within Laguna Park and hot works which can be topics for the workshop.

2.5

Peter JHZH

INFO

JHZH

JHZH

JHZH T309P informed to include in the risk register, if not already included: 1. burning of plant equipment 2. loading/ unloading of material

2.6

LYL T309P informed QPS to include an I&M risk register which can be discussed in the next workshop.

Any Other Matters: 3.0

The next workshop shall cover traffic diversion within Laguna Park or hot works in general.

Page 2 of 3

INFO

Minutes ITEM

MATTERS DISCUSSED

ACTION

Next Workshop 4.0 The next weekly workshop will be scheduled on 25 May 17 @ 10am.

Page 3 of 3

All / Info

100

100

T309/CNSS

T309/CNSS

ERSS for Temporary Work

008

007

T309/CDSS/100/008

T309/CDSS/100/007

Trenching

Lifting with crane

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

Instability of temporary works (trenches)

● Differential settlement between station ERSS ● Failure of loose material, equipment/ rebar cage ● Instability of working platform

Hazard

4

5 Hazard Cause

ERSS wall construction within F1 soil layer - F1 soil layer collapse - Trench stability

- Not identifying the behaviour and response of the ground and adjacent structures

Flawed design of temporary works - Inappropriate use / misinterpretation of design codes - Lack of understanding of design software and output - Incorrect information on adjacent structures - Temporary works design is incompatible with adjacent structures

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Doc no: T309-JHZH-RAR-PWD-RIS-0001

- Collapse of temporary works - Excessive movement/Collapse of adjacent structures - Injury or fatalities of public and Construction workers

- Collapse of temporary works - Collapse / damage of adjacent structures - damage of permanent works - Injury or fatality of construction workers or public

Impact

6

The Risk Register is a "live document" and it will be the responsibility of all parties involved in the design, construction and commissioning of the T309 Project and to ensure that all reasonable means and measures are put in place for the effective management of all the safety risks.to continue to identify new risks that arises.

e

Package 1

F

V

V

V

7

I

I

I

S

C

C

C

Ri

Initial Risk Category Ri

8

- Contractor to produce robust design - Appropriate design sensitivity - Specify minimum penetration of panels - Additional site investigation - Pre-qualify contractors - Emergency Response planning - Provide temporary strut with PE endorsement

- Review levels to be developed - Regular review of Instrumentation / monitoring e.g. LBs to monitor building movement, LGs for ground movement and IW or XYZ for ERSS. - Approved Permit to lift and lifting plan - Lifting Supervisor to ensure correct method of usage - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Avoid loading and unloading near edge of properties or access walkways - Low speed in lifting and lowering of material '- Signaller to communicate with crane operator during lifting and lowering operation - Lifting points to be identified, marked and approved

- Contractor to produce robust design - Approved Permit to lift and lifting plan - Lifting Supervisor to ensure correct method of usage - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Avoid loading and unloading near edge of properties or access walkways - Low speed in lifting and lowering of material '- Signaller to communicate with crane operator during lifting and lowering operation - Lifting points to be identified, marked and approved

Mitigation Measures

I

I

V

V

I

S

V

F

C

C

C

Ri

Residual Risk Category Rr

11

12

JHZH-PM - Regular review instrumentation reading - Perform probing and SI (SPT) at regular intervals - Perform Ground Improvements when necessary - Joint inspection between JHZHJV and QPS for every Dwall 1) Mild case (to read; less than 10% of total panel excavated volume) – Create an earth bund wall surrounding the affected panel, fill up the bund wall pool with bentonite to increase the bentonite head level. 2) Moderate case (to read; more than 10% of total panel excavated volume, without any visual ground/ platform depression) – Move the grabber and other unnecessary heavy equipment at least 20m away from the affected panel, and backfill the panel with LSS to the ground level by tremie method. 3) On a case by case basis for a severe case (to read; more than 10% of total panel excavated volume, with obvious visual ground/ platform depression) – Move all machinery away except excavator at least 20m away from the affected panel, and backfill the panel with LSS to the ground level by tremie method. After 24 hours of backfilling, conduct light cement grout beneath the depressed platform.

JHZH-PM

JHZH-PM

- Steel plate to ensure uniform loading of crane JHZH-PM weight and outrigger - Use of level indicator and inclinometer - Additional site investigation when necessary - Lifting zone to be barricaded before works commence 1) Mild case (to read; less than 10% of total panel excavated volume) – Create an earth bund wall surrounding the affected panel, fill up the bund wall pool with bentonite to increase the bentonite head level. 2) Moderate case (to read; more than 10% of total panel excavated volume, without any visual ground/ platform depression) – Move the grabber and other unnecessary heavy equipment at least 20m away from the affected panel, and backfill the panel with LSS to the ground level by tremie method. 3) On a case by case basis for a severe case (to read; more than 10% of total panel excavated volume, with obvious visual ground/ platform depression) – Move all machinery away except excavator at least 20m away from the affected panel, and backfill the panel with LSS to the ground level by tremie method. After 24 hours of backfilling, conduct light cement grout beneath the depressed platform.

*Action Owner

JHZH-PM

Risk Owner

- Steel plate to ensure uniform loading of crane JHZH-PM weight and outrigger - Use of level indicator and inclinometer - Additional site investigation when necessary - Emergency Response planning including Contingency planning e.g. stop all excavation, ensure safe escape route for workers, additional temporary struts. - Lifting zone to be barricaded before works commence - Lift load by 300mm, hold for 3 seconds, all personnel 3m away Approved lifting plan, reviewed by LE and approved by PM - Lifting points to be identified and approved - Low speed in lifting and lowering - Material shall be stacked safely and within stacking limit and load - Safety zone established - Signaler to communicate with crane operator

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Summary of Residual Risk Classes A 0 B 0 C 74 D 15 89

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

Summary of Initial Risk Classes A 0 B 22 C 60 D 7 89

Apr-17

Apr-17

Apr-17

Due Date By

Revision I 13 14

7 months

7 months

7 months

Risk Exposure Period

C

C

ipe

Target Risk Rating

Open

Open

Open

Status

Date: 23/05/2017 15 16

17 Remarks

010

100

100

100

T309/CNSS

T309/CNSS

T309/CNSS

012

011

009

100

T309/CNSS

T309/CDSS/100/012

T309/CDSS/100/011

T309/CDSS/100/010

T309/CDSS/100/009

Construction of ERSS for Utility Diversion

Construction of ERSS for Drain Diversion

Construction of ERSS

Construction of ERSS

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

Instability of temporary works (Utility Diversion ERSS)

Instability of temporary works (Drain Diversion ERSS)

Excessive ground movement of adjacent structures and utilities

Instability of temporary works (ERSS failure)

Hazard

4

5 Hazard Cause

6 Impact

F

Structural damage/deflection of existing structures - Damage to utilities - Traffic accidents with associated injuries - injuries to public or construction workers associated with ramp distress - Damage to road surfaces - Wall toe movement

- Damage to utilities - Damage to road surfaces

-Higher than expected lateral deflection of ERSS wall during excavations - Unforeseen ground conditions - Inappropriate removal of struts - Over-excavation - Excavation for the utilities laying/trench

- Unforeseen higher than designed surcharge

- Damage to utilities - Damage to road surfaces

- Unforeseen higher than designed surcharge

IV

IV

III

III

III

III

IV

- Injuries to public or construction workers associated with ramp distress - Traffic accidents with associated injuries - Structure Integrity of sheet piles.

- Inappropriate removal of struts - Over-excavation - Excavation for the drain and damage ERSS - Sheet pile obstructed and not able to pile into required depth. -Poor quality weld and design of sheet pile bracing.

IV

III

III

III

IV

IV

IV

I

I

V

V

I

I

S

V

V

7

C

C

C

C

C

C

C

C

C

C

C

Ri

Initial Risk Category Ri

- Structural damage/deflection of existing structures - Damage to utilities - Injuries to public or construction workers associated with ramp distress - Damage to road surfaces - Wall toe movement

Structural damage/deflection of existing structures - damage to utilities - Traffic accidents with associated injuries - injuries to public or construction workers associated with ramp distress - damage to road surfaces - Wall toe movement

Package 1 8

- PE to ensure surcharge level to within acceptable loading

- Contractor to produce robust design - Method Statements to ensure safe working methods - Monitoring on site - Gather knowledge from people with relevant experience - Visual inspection

- PE to ensure surcharge level to within acceptable loading

- Method Statements to ensure safe working methods -Follow the PTW (e.g excavate) daily during work - Review design of sheet pile and provide COS. - Only certified and appointed welders are allowed to weld. - Method statement to ensure proper bracing is provided.

- Contractor to produce robust design - Method Statements to ensure safe working methods - Gather knowledge from people with relevant experience

- PE to ensure surcharge level to within acceptable loading

- Contractor to produce robust design - Method Statements to ensure safe working methods -Regular review instrumentation reading - Apply PTW (e.g. excavate) daily before commencement of work

- Calculate amount of bentonite level required

- Robust Contractor's ERSS system - Pre-qualify contractors

- Contractor to produce robust design - Appropriate design sensitivity

- Contractor’s Method Statements - Apply PTW (e.g. excavate) daily before commencement of work '- Emergency Response Planning including Contingency planning e.g. grouting of gaps - Additional site investigation

Mitigation Measures

V

V

III

III

III

III

V

V

III

III

III

I

I

V

IV

IV

V

V

I

I

V

V

S

F

D

D

D

D

D

C

C

C

C

C

C

Ri

Residual Risk Category Rr

11

- No stockpiling

JHZH-PM

-Provide ground improvements when necessary JHZH-PM - Requirements to record penetration into competent stratum on installation -High quality site records -Bearing capacity checks for construction equipment - Installation of additional recharge wells & pressure relief wells as contingencies.

- No stockpiling

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM - instrumentation/monitoring to monitor strut loads. - Daily physical inspection of strutting system

JHZH-PM

JHZH-PM

JHZH-PM -Statutory requirement for QP(Sup) to be responsible for supervision of temporary works. -Emergency Response planning including Contingency planning

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

-Normal/ established procedures for staging the JHZH-PM works to protect adjacent utilities -Permit to remove strut system followed to prevent inappropriate removal of struts -Emergency Response planning including Contingency Planning

- No stockpiling

12 *Action Owner

JHZH-PM

JHZH-PM

Risk Owner

- Control of excavation opening to pouring time JHZH-PM

- High quality construction records - Ensure trench stability - Emergency Response planning

- instrumentation/monitoring to monitor strut loads. - Daily physical inspection of strutting system

-Emergency Response planning including Contingency planning -Instrumentation/monitoring to monitor strut loads. - Instrumentation/ real time monitoring - Perform probing and SI (SPT) at regular intervals - Sufficient vibration monitors with appropriate trigger levels to be installed. - Provision of recharge wells. -Provide proper recharging system -Provide proper filter gravel

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

-Higher than expected lateral deflection of ERSS wall during excavations - Unforeseen ground conditions

- Unforeseen higher than designed surcharge

Higher than expected lateral deflection of ERSS wall during excavations - Unforeseen ground conditions - Inappropriate removal of struts - Over-excavation - Excavation of cut and cover tunnel

- Low bentonite level

Inadequate structural detail connection between - Collapse of temporary works strut, waler to ERSS walls / shafts / excavations - Excessive movement/Collapse of adjacent structures - Injury or fatalities of public and Construction workers - Contractor's ERSS design - Workmanship

- Groundwater drawdown

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Apr-17

Oct-17

Apr-17

Apr-17

Apr-17

Apr-17

Apr-17

Apr-17

Apr-17

Apr-17

Mar-17

Due Date By

Revision I 13 14

7 months

13 months

7 months

7 months

7 months

7 months

7 months

7 months

7 months

7 months

7 months

Risk Exposure Period

C

C

C

C

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Open

Open

Open

Open

Status

Date: 23/05/2017 15 16 17 Remarks

100

100

T309/CNSS

T309/CNSS

014

013

NA

N.A

4

Gaps in sheet piles

Hazard

- Instability of temporary works (kingpost for traffic decking - ERSS) -Poor ground condition -Using of poor condition machinery - Noise pollution -Accidental dislodgement of kingpost during driving Construction of ERSS -Collision of machinery and (Kingpost) site people. for traffic decking

Construction of ERSS (Drainage diversion)

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

5 Hazard Cause

- Poor design lead to undersize kingpost. - Poor workmanship. -Overloading of kingpost with other load not considered in the design. -Toppling of machinery resulting in damage to property. -Injury to surrounding people. -Structure failure of machinery.. -Old machinery and poor maintenance causing disturbance to nearby resident. - Carelessness and inexperience operator. Faulty vibro hammer.

- Supporting structure across the excavation due to lack of diversion corridor

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

- Collapse of temporary works - Collapse / damage of adjacent structures - damage of permanent works - Injury or fatality of construction workers or public

- Leakage through gap in the walls - Damage to services - Groundwater drawdown - Localized collapse of soil in the gap during excavation

Impact

Package 1 7

IV

III

S IV

F III

C

C

Ri

Initial Risk Category Ri

8

- Method Statements to ensure kingpost is constructed according to MS -JV engineer / QPS to supervise kinghpost construction work to esnure quality of workmanship. - Design to allow sufficient safety factor for structure interity of kingpost. -Access to be laid with hardcore and compacted. -I beam to be properly stacked and excluded. -Machine to be inspected and certified by AE. -Regular monthly maintenance of machineries - Work zone to be barricaded to prevent unauthorized entry - Used of tag line to control swaying of load. - Only allow skilled operator and experienced lifting team.

- Minimize gaps to minimum size required - Utilities diverted from excavation wherever possible - Instrumentation around gap area when necessary

Mitigation Measures

V

III

S IV

F IV

D

D

Ri

Residual Risk Category Rr

11 Risk Owner

- During construction phase, ensure RA control JHZH-PM measure are implemented - e.g. -Segregation of man and machines -Provide designated pedestrian access for wokers. - Provide adequate warning signs. - Provide proper barricades around bore hole. -Installed sound barrier - Used of silent piler - Refrain from working at night and weekend /PH - Additional sling tied to sheet pile and machinery as extra protection in case grabber gives way. - Access to be laid with hard-core and compacted. - kingpost to be laid on top of hard-core.

JHZH-PM - Reinstall sheet piles if there are gaps during installation - Emergency Response Planning including Contingency Planning (e.g. immediate removal works upon sighting of unfavaourable ground/wall movements) 1) Mild case (to read; less than 10% of total panel excavated volume) – Create an earth bund wall surrounding the affected panel, fill up the bund wall pool with bentonite to increase the bentonite head level. 2) Moderate case (to read; more than 10% of total panel excavated volume, without any visual ground/ platform depression) – Move the grabber and other unnecessary heavy equipment at least 20m away from the affected panel, and backfill the panel with LSS to the ground level by tremie method. 3) On a case by case basis for a severe case (to read; more than 10% of total panel excavated volume, with obvious visual ground/ platform depression) – Move all machinery away except excavator at least 20m away from the affected panel, and backfill the panel with LSS to the ground level by tremie method. After 24 hours of backfilling, conduct light cement grout beneath the depressed platform.

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

12

JHZH-PM

JHZH-PM

*Action Owner

Apr-17

Apr-17

Due Date By

Revision I 13 14

7 months

7 months

Risk Exposure Period

C

C

Target Risk Rating

Open

Open

Status

Date: 23/05/2017 15 16 17 Remarks

102

102

102

102

102

102

102

Diaphragm walling T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

007

006

005

004

003

002

001

NA

NA

N.A

T309/CDSS/102/004

T309/CDSS/102/003

T309/CDSS/102/002

T309/CDSS/102/001

Barrette pile test

Welding Works with Welding inverter

Welding Works with Oxygen acetylene and Welding inverter

Diaphragm walling

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

5

-Instability of ERSS wall trenches - Low shear strength in Marine Clay - Loose fills - Possible removal of buried obstructions - Presence of thick peaty layers - High pore water pressure in Marine Clay - Close proximity of adjacent activities such as jet grout piles or casting of nearby trench -Leakage of Bentonite from D wall -Poor Bentonite mixe.

Hazard Cause

6

- Structural damage/deflection of existing structures - Damage to utilities - Traffic accidents with associated injuries - Damage to road surfaces - Collapse of D wall

Impact

Kentledge collapse

- Failure of jack, jack force is not locked in - Unbalance pressure force in jack

- Testing of D-wall

- Improper maintenance of welding set - Improper connection and damaged cables - welding set not fully protected from wet surfaces - Welding in open space during wet weather condition

- Injury to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Injury to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Injury to public or construction personnel - Delays - Claims -Reputation

IV

IV

IV

I

I

I

II

IV

- Injury to public or construction personnel - Delays - Claims - Damage to permanent and temporary works

Fire sparks, fire explosion - Inappropriate welding of struts - Inappropriate welding of Traffic Deck due to Gas leaks, hose damaged, fitting damaged - Inappropriate welding of Noise Barriers - Incompetent welder deployed

Electrocution due to electrical leak

III

III

III

V

V

II

S

IV

F

V

#NAME?

7

B

B

B

C

D

D

D

C

Ri

Initial Risk Category Ri

- Water ingress - Lost toe stability - Loss of fines - Settlement of structures

-Inappropriate diaphragm wall design - Inappropriate use / misinterpretation of design codes

Package 1 8

- Contractor shall provide -uniform hydraulic pressure supply to all jacks to main balance force in test - Mechanical safe lock (safety valve) to lock pressure in jack during jack operation in case of pressure loss

- Test set up must get endorsement of PE

- PPE: Welding face shield, apron and gauntlet - Apply PTW (e.g. hot works) daily before commencement of work - Electrical wires to be secured above ground - Daily welding set checklist/ inspection - Certified welders - Reminder in Tool box meeting

- PPE: Welding face shield, apron and gauntlet - Proper housekeeping - Method Statements (e.g. - Close main value & flush hose line after usage) - Apply PTW (e.g. hot works) daily before commencements of works - Daily welding set checklist/ inspection - Fire extinguishers and fire blankets - Reminder in Tool box meeting '- Certified welders - Welding screen to contain sparks

- Specifying waterproofing details @ interface

- Use of adequate plant / equipment for diaphragm wall construction -Apply PTW (e.g. lifting) daily before commencements of works - Cage to be within lifting equipment capacity - Lifting points to be identified, marked and approved - Use of tandem lifting and explain in Safe Work Procedure - Close supervision by lifting engineer and signalman

- Emergency Response Planning including Contingency planning e.g. grouting of gaps - Method Statements to ensure safe working methods - Apply PTW (e.g. excavate) daily before commencement of work

- Method Statements to ensure safe working methods - Regular monitoring of critical structures - Stability calculations - Contingency planning e.g. (backfilling) in case of collapse, additional temporary struts - Trial panel - Raised guide walls - Control of bentonite properties (e.g. viscosity, sand content, PH value, density) - Visual inspection - Pre-qualify contractors -Apply PTW (e.g. excavate) daily before commencement of work - Deploy worker to monitor Bentonite level especially over week end.

Mitigation Measures

V

V

V

V

V

I

I

I

I

III

III

III

V

V

II

S

IV

F

C

C

C

C

D

D

D

C

Ri

Residual Risk Category Rr

11 Risk Owner

12

JHZH-PM

- Provide physical barrier (interlocked properly) JHZH-PM and safety signs around test sites - Emergency Response planning including Contingency planning - Proper design of kentledge system - Pre-qualify the subcontractor - Approved Method Statement

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

*Action Owner

JHZH-PM

JHZH-PM

-Monitoring of overall settlement and differential JHZH-PM settlement of the kentledge - Provide physical barrier (interlocked properly) and safety signs around test sites - Emergency Response planning including Contingency planning - Proper design of kentledge system - Pre-qualify the subcontractor - Approved Method Statement

-No welding work under rain weather/ wet surfaces - Monthly inspection of welding equipment - Apply Safe Work procedure - Electrical neoprene cable double insulated

- Remove flammable items (timber, canvas etc.. )from welding premises - Monthly inspection of welding equipment - Apply Safe Work Procedure - Implement PTW -Hot work

- High quality construction inspection and records - Method Statements to ensure safe working methods - Use of adequate plant/equipment for ERSS wall construction

- Adopt approved lifting plan - Ensure lifting equipment are inspected monthly - Lifting zone to be barricaded before works commence

- Proper post-cast for structure - Specifying waterproofing details @ interface

-Normal/ established procedures for staging the JHZH-PM works to protect adjacent utilities -Regular review instrumentation reading -Permit to remove strut system followed to prevent inappropriate removal of struts -No stockpiling against D-wall -Emergency Response planning including Contingency planning - Never start D-walling without having the cages ready.

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

Inadequate water tightness - Poor concrete compaction - Inadequate concrete cover and reduced durability due to honeycomb - Poor workmanship

Diaphragm wall cage too heavy to be lifted - Irregular D-wall cage to be lifted

Gaps in retaining systems Provision for services to pass through retaining -Cracking / leakage systems - Structural Damage - Waterproofing problems and associated repair

Excessive ground movement of adjacent structures and utilities

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Mar-17

Mar-17

Oct-17

Oct-17

Oct-17

Oct-17

Oct-17

Oct-17

Due Date By

Revision I 13 14

7 months

7 months

13 months

13 months

13 months

13 months

13 months

13 months

Risk Exposure Period

C

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Open

Status

Date: 23/05/2017 15 16 17 Remarks

102

102

102

102

102

T309/CNSS

T309/CNSS

Pilling T309/CNSS

T309/CNSS

T309/CNSS

011

010

009

009

008

NA

T309/CDSS/102/004

T309/CDSS/102/001

NA

NA

Bored pile test

Piling

Lifting with crane

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

5

-Instability of ERSS wall trenches - Low shear strength in Marine Clay - Loose fills - Possible removal of buried obstructions - Presence of thick peaty layers - High pore water pressure in Marine Clay - Close proximity of adjacent activities such as jet grout piles or casting of nearby trench

Kentledge collapse

- Failure of jack, jack force is not locked in - Unbalance pressure force in jack

- Bored Pile testing

Inadequate water tightness - Poor concrete compaction - Inadequate concrete cover and reduced durability due to honeycomb - Poor workmanship

Excessive ground movement of adjacent structures and utilities

- Poor design - Poor workmanship - Poor rigging method

- Improper securing of material/ equipment/ cages - Overloading of material/ equipment/ cages - Slight tilt in crane '- Sudden movement of crane boom

Failing of loose material/ equipment/ rebar cages

In Stability of rebar cage (including cages for Lshape d-wall panel)

- Breakage of lifting chain - Breakage of lifting sling - Failure of brake motor/gear - Failure of sling/chain buckles and hooks - Overloading of carried loads over limited of design capacity - Unauthorized modification of lifting points -Inadequate rigging method.

Hazard Cause

Failure of lifting mechanism

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

7

- Injury to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Injury to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Water ingress - Lost toe Stability - Loss of fines - Settlement of structures

- Structural damage/deflection of existing structures - Damage to utilities - Traffic accidents with associated injuries - Damage to road surfaces

IV

IV

V

IV

IV

I

I

III

II

I

I

IV

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Injury to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities - Rebar cage fall off during lifting process. - Crane damanged by swing load e.g. windscreen damaged by lifted rebar cage.

I

S

IV

F

B

B

D

C

B

B

B

Ri

Initial Risk Category Ri

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities -Crane topple -Tanish reputation

Impact

Package 1 8

- Contractor shall provide -uniform hydraulic pressure supply to all jacks to main balance force in test - Mechanical safe lock (safety valve) to lock pressure in jack during jack operation in case of pressure loss

- Test set up must get endorsement of PE

- Use of adequate plant / equipment for ERSS wall construction

- Method Statements to ensure safe working methods - Regular monitoring of critical structures - Stability calculations - Contingency planning e.g. (backfilling) in case of collapse, additional temporary struts - Trial panel - Raised guide walls - Control of bentonite properties (e.g. viscosity, sand content, PH value, density) - Visual inspection - Pre-qualify contractors - Apply PTW (e.g. piling) daily before commencement of work

- Cage design must get endorsement of PE - Regular inspection of interface with good records - Lifting points to be marked, identified and approved - Engineer to be present to confirm lifting points prior liftng rebar cage. - Ensure moin load radius is taken into consideration when preparing lift plan.

- Approved PTW (e.g lifting) daily before commencement of work - Lifting Supervisor to ensure correct method of usage - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Avoid loading and unloading near edge of properties or access walkways - Low speed in lifting and lowering of material '- Signaller to communicate with crane operator during lifting and lowering operation - Lifting points to be marked, identified and approved - Approved Lifting plan - Material shall be stacked safely and within stacking limit and load

- Apply PTW (e.g. lifting) daily before commencement of work - Monthly inspection of lifting mechanisms - Lifting Supervisor to ensure correct method of usage - Colour coding all lifting mechanisms for validity and serviceability levels - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Lifting points to be marked, identified and approved - Approved Lifting Plan -Weekly boom down inspection with mechanics

Mitigation Measures

V

V

V

IV

I

I

III

II

I

I

V

V

I

S

V

F

C

C

D

C

C

C

C

Ri

Residual Risk Category Rr

11

12

JHZH-PM

JHZH-PM

- Provide physical barrier (interlocked properly) JHZH-PM and safety signs around test sites - Emergency Response planning including Contingency planning - Proper design of kentledge system - Pre-qualify the subcontractor - Approved Method Statement

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

*Action Owner

JHZH-PM

Risk Owner

-Monitoring of overall settlement and differential JHZH-PM settlement of the kentledge - Provide physical barrier (interlocked properly) and safety signs around test sites Contingency planning - Emergency Response planning - Proper design of kentledge system - Pre-qualify the subcontractor - Approved Method Statement

- High quality construction inspection and records - Method Statements to ensure safe working methods

- Regular review Instrumentation reading -Permit to remove strut system followed to prevent inappropriate removal of struts - Emergency Response planning - Review SI report and cross check at site - Provide water relief wells when necessary

- Emergency Response planning including Contingency planning - Adopt 3X3 lifting principles. - Only R/S is allowed to give signal to crane operator.

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

Mar-17

Mar-17

Mar-17

Mar-17

Mar-17

Oct-17

Oct-17

Due Date By

Revision I 13 14

7 months

7 months

7 months

7 months

7 months

13 months

13 months

Risk Exposure Period

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Status

Date: 23/05/2017 15 16 17 Remarks

105

T309/CNSS

003

T309/CDSS/105/003

T309/CDSS/105/002

105

T309/CNSS

002

T309/CDSS/105/001

Adjacent Structures or Buildings T309/CNSS 105 001

NA

T309/CDSS/103/001

103

Permanent Works T309/CNSS

012

001

102

T309/CNSS

Construction work nearby to adjacent structures or buildings

Construction work nearby stake holders

Construction work nearby to school

Construction of Permanent Works

Lifting with crane

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

5

- Breakage of lifting chain - Breakage of lifting sling - Failure of brake motor/gear - Failure of sling/chain buckles and hooks - Overloading of carried loads over limited of design capacity - Unauthorized modification of lifting points

Hazard Cause

- Improper securing of material/ equipment/ cages - Overloading of material/ equipment/ cages - Slight tilt in crane '- Sudden movement of crane boom

Excessive ground and building settlement

Damage / excessive settlement to buildings/structures: - Victoria School Access Bridge - 2-storey semi-detached houses at Kee Sun Ave - St. Andrew's Autism Centre - Elliot at The East Coast - Laguna Park Electrical Substation (Block 5000F) - 2-storey semi-detached houses at Elliot Walk - Opera Estate Canal & Culverts Interface with the public.

Stop or delay school operation. Interface with the public.

- Activation criteria and minimum head are not given

- Ineffectiveness of recharge well layout given in the A/E design '- Some recharge well points will not provide effective recharging due to their locations being far from the buildings to be protected - Filter may not be compatible with the existing ground conditions - Pile test and D-wall test

-Long term settlements - Scheduling of work planning

-Unforeseen ground conditions -Excavation works causing unforeseen settlements -Groundwater drawdown

-Proximity of schools has special implications, -Victoria school is boarding school) - Scheduling of work planning

Excessive settlement - Insufficient ground information available for (Victoria School bridge and design canal structures)

Failing of loose material/ equipment/ rebar cages

Crane topple / Hoisted load - Poor crane footage hit crane - Incompetent lifting team - Poor lift plan - Congested work environment

Failure of lifting mechanism

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

7

- Damage to utilities - Damage to property

- Disruption to the site activities during installation of recharge well - Blockage of the filter gravel - Excessive water flow rate provided by the pumping system but little recharging effect

- Claims - Damage to buildings/structures - Complains from the public - Injuring the public

- Damage to buildings/structures - Delays - Claims - Closure of roads - Injuries / fatalities of construction workers and public

-Noise disruption to schools -Pick up and drop off times Damaged - Complains from the public - Injuring the public

- Serviceability issue with the bridge

IV

IV

V

V

III

IV

IV

III

III

I

I

IV

III

I

I

IV

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

I

S

IV

F

C

C

C

C

C

C

B

B

B

Ri

Initial Risk Category Ri

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

Impact

Package 1 8

-Activation criteria and minimum have been designed and indicated (Zone 1 to 3)

- Contractor's consultant has designed the recharging system, modified the configuration - Design of filter gravel has been provided

- Instrumentation / Monitoring - Reduce work inteface with public during peak hours

- Contractor’s Method Statements - instrumentation / monitoring - Real time monitoring - Specification of instrumentation and monitoring requirements by AE consultant - Strengthening and temporary propping when necessary - Additional site investigation

- Contingency planning, inspection and monitoring - Method Statements - Additional site supervision (e.g. traffic marshal) - Reduce work inteface with public during peak hours

- Provision of additional boreholes for bridge and canal design

- Approved PTW (e.g lifting) daily before commencement of work - Lifting Supervisor to ensure correct method of usage - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Avoid loading and unloading near edge of properties or access walkways - Low speed in lifting and lowering of material '- Signaller to communicate with crane operator during lifting and lowering operation - Lifting points to be marked, identified and approved - Approved Lifting plan - Material shall be stacked safely and within stacking limit and load

- Design and COS crane access - No Overloading at all times - Proper maintenance of crane - Only competent lifting team is allowed - Implemet Permit to lift - Include both Max. and Min load radius - Do not conduct lifting in congested work environment. - Provide exclusion zone and Provide warning signs. - Provide sufficient tag lines

- Apply PTW (e.g. lifting) daily before commencement of work - Monthly inspection of lifting mechanisms - Lifting Supervisor to ensure correct method of usage - Colour coding all lifting mechanisms for validity and serviceability levels - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Lifting points to be marked, identified and approved - Approved Lifting Plan

Mitigation Measures

IV

IV

V

V

III

IV

III

III

I

I

IV

III

I

I

V

V

I

S

V

F

C

C

C

C

C

C

C

C

C

Ri

Residual Risk Category Rr

11

- Provide proper recharging system - Provide proper filter gravel - Instrumentation/ Monitoring of settlement - Additional Site investigation

- Emergency Response planning - Provide proper recharging system - Provide proper filter gravel - Instrumentation/ Monitoring of settlement - Additional Site investigation - Control of bentonite pressures

- Perform ground improvements when necessary

-Emergency Response planning including Contingency planning -Instrumentation/monitoring to monitor strut loads. - Instrumentation/ real time monitoring - Sufficient vibration monitors with appropriate trigger levels to be installed. - Provision of recharge wells. -Provide proper recharging system -Provide proper filter gravel

12

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

*Action Owner

JHZH-PM

Risk Owner

JHZH-PM - Proper planning and traffic control - Provide soundproof wall - Close communication with the school and be cognisant of critical times in the school calendar

- Emergency Response planning - Insturmentation and monitoring of settlement - Additional Site investigation when necessary

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

May-20

Oct-17

Oct-17

Oct-17

Due Date By

Revision I 13 14

79 months

79 months

79 months

79 months

79 months

45 months

13 months

13 months

13 months

Risk Exposure Period

C

C

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Open

Open

Status

Date: 23/05/2017 15 16 17 Remarks

105

105

T309/ CNSS

T309/CNSS

005

004

N.A

NA

Road diversion work (Laguna park)

Traffic Diversion around Victoria School

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

- Congested road leading to Victoria school - Construction activities in front of Victoria school - Heavy machinery stationed along Siglap Link - Heavy traffic from new egress to Marine Parade Road - Pedestrians jaywalking -Inadequate signage and poor traffic control measures -Unsafe traffic layout -Failure to carryout trial trench for UG services -Failure to barricade work area and provide banksman to guide vehicular movement on site -Failure to equip with proper PPE

- Congested road leading to Laguna Park - Construction activities in front of Laguna Park - Heavy machinery stationed in Laguna Park - Heavy traffic from new egress to Marine Parade Road - Pedestrians jaywalking -Inadequate signage and poor traffic control measures -Unsafe traffic layout -Failure to carryout trial trench for UG services -Failure to barricade work area and provide banksman to guide vehicular movement on site -Failure to equip with proper PPE

Risk associated with Traffic Diversion -Unsafe traffic conditions, accident hot spot and vehicles crashing into site -Damaged to UG services -Noise and dust pollution

Risk associated with Traffic Diversion -Unsafe traffic conditions, accident hot spot and vehicles crashing into site -Damaged to UG services -Noise and dust pollution

5 Hazard Cause

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

- Collision of construction and public vehicles - Delays - Claims - Injury to public or construction personnel

- Collision of construction and public vehicles - Delays - Claims - Injury to public or construction personnel

Impact

Package 1 7

II

II

IV

S

F IV

C

C

Ri

Initial Risk Category Ri

8

- Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan '- Guard rail or rigid barrier to be setup and interlocked properly - designated path for access by pedestrians '- Code of Practise of Traffic Control and Work Zone -Approval of temporary traffic diversion layout by TM -Traffic layout and signage to follow TCP -Submit PSR (road) for clearance -Ensure good visibility of signage --Apply permit to dig prior to start work -Conduct RA/ SWP briefing

- Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan '- Guard rail or rigid barrier to be setup and interlocked properly - designated path for access by pedestrians '- Code of Practise of Traffic Control and Work Zone -Approval of temporary traffic diversion layout by TM -Traffic layout and signage to follow TCP -Submit PSR (road) for clearance -Ensure good visibility of signage --Apply permit to dig prior to start work -Conduct RA/ SWP briefing

Mitigation Measures

II

II

IV

S

F IV

C

C

Ri

Residual Risk Category Rr

11 Risk Owner

JHZH-PM - To provide traffic marshals to direct traffic when necessary - To study provision of temporary traffic lights to faciltate passing of construction and public vehicles smoothly when necessary - Placement of cone or barrier during diversion without reduction in lane width -Desk top study of all utilities and carryout appropriate trial trench -Barricade work area and provide proper signage and warning to motorist and pedestrian. -Lane closure to avoid peak hours, applicable hours is 9:30-16:30 for daytime and 16:30-09:30 for night time closure -Flow chart indicating the flow of instruction enabling the lorry truck to enter the lane closure work area during soil removal or delivery of materials.

JHZH-PM - To provide traffic marshals to direct traffic when necessary - To study provision of temporary traffic lights to faciltate passing of construction and public vehicles smoothly when necessary - Placement of cone or barrier during diversion without reduction in lane width -Desk top study of all utilities and carryout appropriate trial trench -Barricade work area and provide proper signage and warning to motorist and pedestrian. -Lane closure to avoid peak hours, applicable hours is 9:30-16:30 for daytime and 16:30-09:30 for night time closure -Flow chart indicating the flow of instruction enabling the lorry truck to enter the lane closure work area during soil removal or delivery of materials.

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

12

JHZH-PM

JHZH-PM

*Action Owner

Jul-17

Mar-23

Due Date By

Revision I 13 14

17 months

79 months

Risk Exposure Period

C

C

Target Risk Rating

Open

Open

Status

Date: 23/05/2017 15 16 17 Remarks

005

Future developments or Addition & Alteration works T309/CNSS 112 001 T309/CDSS/112/001

110

T309/CDSS/110/005

N.A

T309/CNSS

109

Existing Conditions T309/CNSS

004

T309/CDSS/106/003

T309/CDSS/110/004

106

T309/CNSS

003

T309/CDSS/106/002

Interface with Adjacent Contracts T309/CNSS 110 004

106

T309/CNSS

002

T309/CDSS/106/001

T309/CDSS/109/006

106

T309/CNSS

001

006

106

Existing Utilities T309/CNSS

Future developments or Addition & Alteration works

Excavation

Excavation

Excavation for Utility Diversion Works

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

Clashes between railway structures and future underground infrastructure works and/or future above ground developments

Interfacing with adjacent contracts

Incompatible Interfacing with adjacent contracts

Seawall obstruction

Limited Work Areas

Damage to utilities

Damage to utilities and disruption to services

Damage to submarine cable

Hazard

4

5 Hazard Cause

- Injury or fatalities of public and construction workers Unplanned excavation -Insufficient marking on site -Failure to conduct detection test

- Damage to the equipment used - Deep foundation and diaphragm wall are not constructed properly

- Unforeseen higher than designed surcharge

- Damage to utilities - Damage to road surfaces - Damage to property

-Proposals for future underground infrastructure - Incompatible construction techniques and developments in direct conflict with alignment and stations - Delay of works - Unaware of future infrastructure and developments proposals

Effect of T310 TBM tunnels on D-Walls subway - Excessive ground movement near Entrance C - Movement to adjacent structures

Unappropriate or non-workable connection - Excessive ground movement design at interface of bored tunnels and station - Movement to adjacent structures end walls - Groundwater drawdown - Waterproofing problem and associated repairs

Abandon seawall

- Work areas too restricted or efficient workings - Schedule delays - Work areas require significant temporary - Unsafe environment for construction works for their establishment personnel traffic congestion

-Diversion and support of utilities across excavation: - Water pipe - Power Grid cables - SP Telecom cables - Starhub cables

6 Impact

Disturbance to public

-Non coordinated inter-contract utility diversion, - Delay - Remote disruption -Unforeseen obstructions - Missing information from utilities agencies - Insufficient trial trenches

Insufficient information about cable location

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Package 1

F

V

V

V

V

IV

II

II

I

I

IV

III

I

V

III

III

I

S

III

V

7

C

C

C

C

D

C

C

C

C

Ri

Initial Risk Category Ri

8

- PE to ensure surcharge level to within acceptable loading

- Contractor to review Development Interface Report in detail - Coordination meetings between interfacing designers - Coordination between all parties (Client, Contractor, designers)

- Coordination meetings between interfacing contractors and designers to be managed by Contractors - Construction Interface report by Contractor - Coordination between all parties (Client, Contractor, Designers)

- Coordination meetings between interfacing contractors - Construction Interface report by Contractor - Coordination between all parties (Client, Contractor, Designers) - Specifying waterproofing details @ interface

- Additional trial trench and site investigation

- Buidling temporary decking for efficient road/land use - Detailed SHE procedure to enforce safety

- Ongoing co-ordination with relevant utility companies - Contractor's Method Statement - Approved NCE - Pre-qualify Contractors - Apply PTW daily before commencement of work -Thorough study of utilities drawings -Cable detections by qualified LCDW -Provide clear utilities marking on site -Provide A3 size drawing of utility plan -Apply permit to dig -Barricade work area while trenching -Contact relevant utility agency for any presence of unidentified utility -Always treat utility as `live’ if encountered -Only manual digging allowed for trial trench -Full time supervision during trial trench -No mechanical excavation within 3 meters from live utilities. - Only manual excavation allowed for trial trench digging. - Brief utilities plan in language understood by the workmen.

- Method Statements - Additional site investigation - Approved NCE

- To divert submarine cable away from the station box

Mitigation Measures

V

V

V

V

IV

II

II

I

I

IV

III

I

V

IV

III

I

S

IV

V

F

C

C

C

C

D

C

C

C

C

Ri

Residual Risk Category Rr

11

12

- No stockpiling

- Close coordination with related parties

- Instrumentation and monitoring - Close coordination

- Emergency Response planning e.g. grouting - Methods Statement - Close coordination

- Cross check at site - Laise with related authority about the information of seawall

- Efficient site utilization plan for each different working stage - Hire a professional road safety review learn and checking when necessary

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

-Utility cable detection and trial trench should be JHZH-PM carried out to identify the alignment -Diversion out of the structure footprint -Emergency Response planning including Contingency planning -Close communication with utilities agencies -Cable detection -Properly mark the location of utilities and briefing site staffs, workers and sub-contractors -If unclear with the finding of services after reaching the 2m limit, conduct further detection to determine the presence of any services below. -Dimensions and depth of Trial Trenches recorded by Project Survey Team for As Build information Photo records of trial trench including any utility discovered are recorded

JHZH-PM

JHZH-PM

-Design protective measures and temporary support scheme for utilities across excavation -Close communication with inter-contract and utilities agencies -Identify clear markers for utilities locations lines and brief staffs, workers and subcontractors -Cable detection -Emergency Response planning including Contingency planning

JHZH-PM

*Action Owner

JHZH-PM

Risk Owner

- Divert submarine cable away from the station JHZH-PM box and identify the clearly marker

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

May-20

May-20

May-20

May-20

Jan-17

Oct-17

Oct-17

Oct-17

Oct-17

Due Date By

Revision I 13 14

45 months

45 months

45 months

45 months

5 months

13 months

13 months

13 months

13 months

Risk Exposure Period

C

C

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Open

Open

Status

Date: 23/05/2017 15 16 17 Remarks

001

002

Ground Improvements T309/CNSS 118

118

121

T309/CNSS

Fire and Explosions T309/CNSS

001

009

Construction Methodology T309/CNSS 117

T309/CDSS/121/001

T309/CDSS/118/002

T309/CDSS/118/001

T309/CDSS/117/009

Construction works involving flammable or explosive materials

Construction works for ERSS or permanent walls

Jet grouting

Lifting with crane

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

5

Inappropriate jet grouting methods

-Overloading of lifting equipment -Failure to observe safe work procedures -- Instability of working platform. - Failure of loose material equipment/ rebar cages - Lack of communication - Inadequate supervision and control - Unplanned and poor control of crane movement - Substandard lift plan

Hazard Cause

Fire or explosion during construction

-Encounter flammable materials - Breakage of buried services - Ignition of methane from peat layers - Contaminant gas - War relics/unexploded ordnances - Heavy vehicles carrying flammable materials may be driven into the construction site

Excessive deflection of Insufficient ground improvement / treatment ERSS or permanent walls works

Ground improvement failure

●Crane collapse or failure ●Toppling of crane ●Crane hit surrounding structures, eg silo ●Hoisted material hit crane

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

- Injury or fatality of public or construction workers - Damage to existing structures and services

- Flooding of excavation - Collapse of temporary works and adjacent structures - Injury of public or construction personnel - Disruption of essential services - Delays - Claims

- Collapse of ground - Injury or fatality of construction workers and public - Waterproofing problems and associated repair - Damage to buildings - Delay of works - Movements of adjacent structures

-Injury to site staff -Delay to construction -Damage to property

Impact

Package 1

IV

F

V

V

V

7

I

II

II

II

S

C

C

C

C

Ri

Initial Risk Category Ri

8

- Provision of appropriate plant - additional site investigation and geophysics when necessary - Gather knowledge from people with relevant experience - Apply PTW (e.g hot works) daily before commencement of work - Safety Datasheet and Warning signs and Emergency contacts on display - Reporting to Safety and Security Department

- Contractor to produce robust Design - Method Statements to ensure safe working methods - Robust ERSS Design - instrumentation / monitoring e.g. LBs to monitor building movement, LGs for ground movement and IW or XYZ for ERSS.

- Contractor to produce robust design - Jet grouting trials - Specifying waterproofing details @ interface - Instrumentation / Monitoring e.g. LBs to monitor building movement, LGs for ground movement and IW or XYZ for ERSS. - Additional site investigation and geophysics

- Provide support plates for firm support - Apply PTW (e.g. lifting) daily before commencement of work - Full extension of outrigger prior to lifting - Approved Lifting Permit - No workers shall be allowed to stand below suspended loads - Lifting Supervisor to ensure correct method of usage - Approved lifting plan (e.g. full extension of outrigger, approved and proper use of slings) - Lifting points to be marked, identified and approved -Safety zone established -Tag line with coloured flag to be installed along hoarding to warn operator from crossing the line when turning during lifting -Tag line with coloured flag to be installed at the top of bentonite tank to warn crane operator and signal man to guide operator during crane movement. -Bentonite tanks near to Dwall will only be erected after the completion of Dwall. -To include min load radius in lift plan.

Mitigation Measures

V

V

V

V

F

I

II

II

II

S

C

C

C

C

Ri

Residual Risk Category Rr

11 Risk Owner

- Proper and independent flammable materials storage and management - Emergency Response Planning including Contingency planning e.g. quick evacuation route - Permit to carry hazardous material

- Provide efficient geometric design and the road level to mitigate flooding - Witness the instrumentation reading - Regular review and analyse instrumentation reading - Emergency Response planning include Contingency planning, inspection and monitoring

JHZH-PM

JHZH-PM

- High quality construction records and material JHZH-PM testing - Methods statement - Pre-qualify contractors - Regular review instrumentation reading of inclinometers and ground settlement markers in trial test and feedback main works - Emergency Response Planning including Contingency planning e.g. stop all excavation, ensure safe escape route for workers, additional temporary struts.

JHZH-PM - Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Reminder in tool box meeting - Lifting zone to be barricaded before works commence -Provide adequate hardstanding /firm working platform -Put in place the lifting permit system and display the relevant details on site. -Ensure no overloading of crane -Signaler to communicate with crane operator -Lift load by 300mm, hold for 3 seconds, all personnel 3m away -Approved lifting plan, reviewed by LE and approved by PM -Lifting operation supervised by lifting supervisor -Banksmen to guide crawler crane movement, ensuring no tracking over drain, trench or uneven ground. -Lifting points to be identified and approved -Low speed in lifting and lowering -Material shall be stacked safely and within stacking limit and load -Authorization of all machineries movement from point to point -Establish a permit to move system for heavy machineries -A lockout /tagout system during maintenance and breakdown period of mchineries -Maincon to control all machineries movement on site with daily discussion during coordination meeting -Setting up a security management plan that involved site security to be aware of the delivery of materials and ensuring no material delivery during lunch time and peak hour

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

12

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

*Action Owner

Mar-23

Jan-18

Jul-17

May-20

Due Date By

Revision I 13 14

79 months

16 months

10 months

45 months

Risk Exposure Period

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Status

Date: 23/05/2017 15 16 17 Remarks

122

999

999

999

999

999

999

999

Flooding T309/CNSS

Other Hazards T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

007

006

005

004

003

002

001

002

N.A

T309/CDSS/999/006

T309/CDSS/999/005

T309/CDSS/999/004

T309/CDSS/999/003

T309/CDSS/999/002

T309/CDSS/999/001

T309/CDSS/122/001

4

5 Hazard Cause

Cleaning

Setting up of Noise Barrier

Traffic Diversion

6

Damage to construction works

-Occurrence of a natural disaster during construction - Flooding - Heavy rainfall causing significant ground water table rise

- Construction activities require frequent transport movements - Works at site with long working hours for 7 days a week

Use of high ultra water jet

Noise Barrier and foundation

-Pipe leakage and burst -Loose connection -Lose control of hose

-Construction works in close proximity to the public and existing housing -Excessive noise due to construction

Movement of heavy -Spoil removed to designated location remote vehicles causing disruption from site to traffic movement

F

- Injury to public or construction personnel

- Injury to public or construction personnel - Disruption of essential services - Negative PR - Delays - Claims

- Delay and accidents, - ECM issues, - Mosquito breeding, - Security problems

IV

II

III

III

III

V

IV

IV

I

V

- Flooding of excavation - Collapse of temporary works and adjacent structures - Injury or fatality of public or construction personnel - Disruption of essential services - Delays - Claims

II

III

I

S

II

IV

IV

V

7

C

D

C

D

C

C

C

C

C

Ri

Initial Risk Category Ri

IV

-Environmental pollution

Package 1 8

- Assign two trained hydro jetting operators. - Rotate shift every alternate hours - Provide safety warning signage to keep other works clear from work area - Provide safety access to washing bay

- Method Statements - additional site investigation - Provision of Noise barrier - Monitoring of Noise - Noise control plan - Engage community regularly and gather feedback

- Method Statements -Additional traffic management

- Method Statements - additional site supervision - ECM Plan

- Robust ERSS design including flood barriers when necessary - Temporary groundwater controls and pumps within excavation - Specifying water proofing details @ interface

- Design and approved traffic diversions - Minimise traffic around construction sites - Use of barrier and/or gate guards for exit/ entrances to site

- Design and approved traffic diversions - Clear and good signages - Minimise traffic around construction sites

- Contingency planning, e.g. additional noise barriers, inspection and monitoring - Method Statements to ensure safe working methods - Installation of noise barriers - Noise level monitoring - Engaging community for feedback '- Noise, dust control plan

- Method Statements - Additional site investigation -Confirmation with LTA on any specific flood protection measures required during construction

Mitigation Measures

V

V

IV

II

III

III

IV

I

V

IV

II

II

III

I

S

V

V

V

V

F

C

D

C

D

C

C

C

D

C

Ri

Residual Risk Category Rr

11 Risk Owner

JHZH-PM

12

JHZH-PM

JHZH-PM

- Assign safety supervisor when possible at work place to ensure operation is safe - Barricade work area to prevent unauthorized access and display warning signage.

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM - To provide traffic marshals to direct traffic when necessary - To study provision of temporary traffic lights to faciltate passing of construction and public vehicles smoothly -Designated haul routes -Contingency planning, inspection and monitoring - Placement of cone or barrier during diversion without reduction in lane width - Minimize loud noise activity during evening and weekends - Monitor noise meters at designated intervals - Contingency planning, inspection and monitoring

JHZH-PM

JHZH-PM - Install additional EC measures (e.g. silt fences, nets) when necessary '- Regular inspection of site by ECO at affected zones - Contingency planning, inspection and monitoring

- Close communication with related authority - Emergency Response planning including Contingency planning e.g. quick evacuation route - Provide efficient geometric design and the road level to mitigate flooding

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

*Action Owner

JHZH-PM - To provide traffic marshals to direct traffic when necessary - Clearly defined zones for accessible pathways and restricted areas - Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan - Guard rail or rigid barrier to be setup and interlocked properly - Code of Practise of Traffic Control and Work Zone - Placement of cone or barrier during diversion without reduction in lane width

JHZH-PM - To provide traffic marshals to direct traffic when necessary - Clearly defined zones for accessible pathways and restricted areas - Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan - Guard rail or rigid barrier to be setup and interlocked properly - Code of Practise of Traffic Control and Work Zone - Placement of cone or barrier during diversion without reduction in lane width

- Vibration control plan - Vibration monitoring

JHZH-PM - Provide efficient geometric design and the road level to mitigate flooding -Awareness of climatic conditions -Regular monitor of water level in Opera estate Canal -Emergency Response planning including Contingency planning

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

- Complaint from nearby occupants - Complaint from LTA - Working time may be reduced with delay to programme

-Traffic congestion due to minimum diversions, - Injury to public or construction personnel drivers seeking alternative routes - Damage to temporary or permanent works

Road vehicles entering construction site / excavations

-Traffic congestion - Unauthorized entry of personnel to site

-Construction works in close proximity to the public -Excessive noise due to construction -Excessive noise due to bored and barette pile testing

- Injury to public or construction personnel - Disruption of essential services - Negative PR - Delays - Claims

-Interrupted construction, -Delays, -Environmental pollution

Impact

Noise, dust and vibration

Flooding from the Opera -Damage the canal or foundation during Estate Canal at Siglap Link construction, -Extreme flooding event; -Tidal fluctuation -Structural problem of the canal

Hazard

Discharge into Canal from -Heavy rain construction - Insufficient control on site -Surface run off, construction materials Construction Works (bentonite, concrete, grout, near Drains and Canal maintenance/cleaning facilities)

Construction Works near Drains and Canal

Traffic Diversion

Construction Works near Residental area

Construction works near Opera East Canal

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Mar-23

Mar-20

Mar-23

Mar-20

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

Due Date By

Revision I 13 14

79 months

45 months

79 months

45 months

79 months

79 months

79 months

79 months

79 months

Risk Exposure Period

C

C

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Open

Open

Status

Date: 23/05/2017 15 16 17 Remarks

999

999

999

999

999

999

999

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

Site set up T309/CNSS

013

21

012

011

010

009

008

NA

N,A

N.A

N.A

N.A

N.A

N.A

Setting up of Noise Barriers

Drain Works

Recahrge well work

Lifting with Excavator (Pick and Carry)

Traffic Diversion

Traffic Diversion

Removal of sludge

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

5

Noise Barrier structural failure

Flooding hazard in confined space

6

- Collapse of temporary works - Excessive movement / Collapse of adjacent structures - Injury or fatalities of public and construction workers

- Flooding of drain - Collapse of temporary works and adjacent structures - Injury of public or construction personnel - Disruption of essential services - Delays - Claims

-Damage of machinery -Injury of worker -Damage of materials

-Damage of machinery -Injury of worker -Damage of materials

- Traffic jams hindering construction vehicles - Bottlenecks hindering traffic speed - Crossed traffic and pedestrian circulation paths - injury to public and/or construction work

- Traffic jams hindering construction vehicles - Bottlenecks hindering traffic speed - Crossed traffic and pedestrian circulation paths - injury to public and/or construction work

'- Injury to public or construction personnel - Contaminate soil, groundwater and surface water

Impact

- Collapse of temporary works - Incorrect information on adjacent structures - Not identifying the behaviour and response of - Damage to own and public properties (Claims) - Injury or fatalities of public and construction the ground and adjacent structures workers

-Flawed design of temporary works - Inappropriate use / misinterpretation of design codes - Lack of understanding of design software and output - Temporary works design is incompatible with adjacent structures

Obstructed access out of drain

-Unplanned Drilling. - Insufficient marking on site. - Failure to conduct detection test.

-Damaged to :

Water pipe. Power grid cables. Telecom cables. High tension cables.

-Uneven ground - Unauthorised lifting - Improper rigging -Overloading -Inexperience operator

-Uneven ground - Unauthorised lifting - Improper rigging -Overloading -Inexperience operator

- Change to road condition due to delivering material to site

- Change to road condition due to construction work, poor line of sight - Changed traffic condition causes confusion to road users - Improper/ unclear signages - Improper/ unclear separation of pedestrians paths and work site ingress/ egress points - Pedestrians jaywalking

-Pipe leakage and burst -Loose connection

Hazard Cause

-“A’ frame topple - Injury to public - Fingers / hand caught in rotating parts

-Toppling of excavator - Falling of load/ material

Risk associated with Traffic Diversion

Risk associated with Traffic Diversion

Sludge spill

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Package 1 7

II

II

IV

II

II

II

II

II

IV

V

IV

IV

IV

IV

II

II

IV

S

F IV

C

C

C

B

B

B

C

C

C

Ri

Initial Risk Category Ri

8

- Perform further structural or geotechnical investigations e.g. coring, trial trenching - Apply PTW (e.g. welding) daily before commencement of work - Certified welder

- Sensitivity of design input parameters - Pre-qualify contractor - Apply PTW (e.g. welding) daily before commencement of work - Certified welder

- Contractor to produce robust Design - Method Statements to ensure safe working methods - Robust ERSS Design

-Thorough study of utilities drawings. - Cable detections by qualified LCDW - Provide clear utilities marking on site - Provide A3 size drawing of utility plan - Apply permit to dig and implement “checklist for working near utility” - Barricade work area while trenching

- Ensure work assess is planned. - Ensure adequate access for work mobilisation and public access. - Only competent lifting crew is allowed to involved in mobilisation. - PTW-Lifting approved prior unloading. - Provide proper exclusion zone to segregate work and public. - Provide warning signs.

●The excavator designed for pick and carry operations must have load chart stating clearly the limitattions for picks and carry operation ●Tag line shall be used during operation ● Ensure the route of travel is firm and level ●Lifting supervisor to ensure the load is firmly secured and tied ●Benchman to guide excavator during the pick and carry operation

- Design stages of traffic diversion to allow construction to be carried out section by section - Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan - Safety barrier to be setup at designated storage zones - Proper signages display at prominent locations - Code of Practise of Traffic Control and Work Zone - designated path for access by pedestrians - Control unauthorized entry of personnel into loading/unloading zone during material delivery

- Design stages of traffic diversion to allow construction to be carried out section by section - Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan - Guard rail or rigid barrier to be setup and interlocked properly Proper signages display at prominent locations - Code of Practise of Traffic Control and Work Zone

- Competent staff - Provide safety warning signage to keep other works clear from work area - Provide safety access to treatment plant - Permit for handling of sludge - Provide emergency contact no.

Mitigation Measures

II

II

V

II

II

II

II

II

V

V

V

V

V

V

II

II

V

V

S

F

C

C

C

C

C

C

C

C

C

Ri

Residual Risk Category Rr

11

JHZH-PM

Risk Owner

JHZH-PM

JHZH-PM

- Strengthening of noise barrier when necessary JHZH-PM - Additional site investigations and localized ground improvement when necessary - Emergency Response planning including Contingency planning e.g. stop all excavation, ensure safe escape route for workers, additional temporary struts. - Approved Method Statement

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

12 *Action Owner

JHZH-PM - Engage experienced and competent consultant to perform the design - Engage experienced and competent contractor - Emergency Response planning including Contingency planning e.g. stop all excavation, ensure safe escape route for workers, additional temporary struts. - Approved Method Statement

- Provide efficient geometric design and the road level to mitigate flooding - Emergency Response planning include Contingency planning, inspection and monitoring - Ensure workers are familiar with confined space ingress/egress in case of flooding and collapse of temporary works

-Contact relevant utility agency for any presence JHZH-PM of unidentified utility Always treat utility as `live’ if encountered Only manual digging allowed for trial trench Full time supervision during trial trench

- Provide blinker lights to alert night motorist and /or pedestrian. - Ensure footage is firm and level at all times. - Never drag load. Lift vertically.

-AE to examine the lifting capacity of excavator JHZH-PM and issued the certification for the lifting. -Pick and carry operation is guided in SS536 : 2008

JHZH-PM - To provide traffic marshals to direct traffic when necessary - To study provision of temporary traffic lights to faciltate passing of construction and public vehicles smoothly - Placement of cone or barrier during diversion without reduction in lane width

JHZH-PM - To provide traffic marshals to direct traffic when necessary - To study provision of temporary traffic lights to faciltate passing of construction and public vehicles smoothly - designated path for access by pedestrians - Placement of cone or barrier during diversion without reduction in lane width

- Contain and handle spillage (e.g. excavate spill site and treat with dry sand, temporary diking) immediately - Contact additional emergency services when necessary

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

Mar-23

Mar-23

Jun-17

May-23

May-23

Mar-23

Mar-23

Mar-23

May-20

Due Date By

Revision I 13 14

79 months

79 months

11 months

79 months

79 months

79 months

79 months

79 months

45 months

Risk Exposure Period

C

C

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Open

Open

Status

Date: 23/05/2017 15 16 17 Remarks

T309/CNSS

999

014

NA

4

MEWP topple

Hit by fallen object

Fall from height

Hazard

5

6

Old machinery and poor maintenance causing disturbance to nearby resident

Installation of sheet piles Noise pollution (foundation support for sound barrier)

Installation of sheet piles Accidental dislodgement of -Carelessness and inexperience operator. (foundation support for sheet pile during driving - Faulty vibro hammer sound barrier)

Structure failure of machinery

Installation of sheet Using of poor condition piles (foundation support for machinery sound barrier)

-Serious injury to worker and property. -Stop work causing delay

-Disturbance to neighbouring resident -Hearing injury to workers

-Low productivity Job delay and behind schedule -Cost implication

-Serious injury to worker and property. -Stop work causing delay

-Toppling of machinery resulting in damage to property. -Injury to surrounding people.

Installation of sheet piles Poor ground condition (foundation support for sound barrier)

-Damage to underground services -Disruption to stakeholders -Penalty charges by authority -Stop work order by authority -Delay to work schedule

Risk Register Package 1

-

IV

IV

IV

IV

IV

IV

7

F

I

II

II

I

I

II

II

S

B

C

C

B

B

C

C

Ri

Initial Risk Category Ri

8

I

-Additional sling tied to sheetpile and machinery as extra protection in case grabber gives way V -Ensure sheetpile is clamped tightly between the grabber jaws before hoisting up vertically for installation

II

I

I

II

II

II

V

V

V

V

F

S

C

C

C

C

C

C

C

Ri

Residual Risk Category Rr

-Installed sound barrier. -Used of silent piler. V -Refrain from working at night and weekend/PH

-Machine to be inspected and certified by AE. -Regular monthly maintenance of machineries

-Access to be laid with hardcore and compacted. -Steelplate to be laid on top of hardcore. -Movement of machinery must be guided by benchemen

-Work zone to be barricaded to prevent unauthorized entry -Used of tag line to control swaying of load - Employed skilled operator and experienced lifting team

-Carry out cable detection and trial trench along the path of sheet piles. V -Apply permit to dig prior to work start.

- Provision of Fall Protection Plan. - Establish PTW-Height system. - Provide proper access. - Provide adequate work platform. - Licensed MEWP operator. - Familiarisation briefing prior appointment.

Mitigation Measures

11 Risk Owner

Daily pre operation check on grabber by operator before start of work

Regular maintenance regime in place

LOTO system applied during maintenance period

-Ground preparation completed with the issuance of COS from PE -Ensure no overloading of machinery (Load kept at 75% of SWL

Apply for permit to move for machinery movement from point to point

Cable detection by LEW

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

-Enveloped MEWP work platform with scaffold JHZH-PM netting to contain material. Limit max. 2 person on MEWP. Max. weight 120kg. Firm and compacted ground for MEWP access. Provide adequate exclusion zone and signage. Provide banksman to ensure no authorised entry in to work zone.

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

-Damage to own and public properties (Claims) IV - Injury or fatalities of public and construction workers

Impact

-Serious injury to worker and property. -Stop work causing delay -Damage to machineries

Location of utilities not reflected in utility drawing

-Failure to provide fall protection provision - Failure to provide control - Poor footage - Over loading of MEWP

Hazard Cause

Installation of sheet Collision of machinery and piles Constraint of work area (foundation support for site people. sound barrier)

Installation of sheet piles Damage to utilities (foundation support for sound barrier)

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 12

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

*Action Owner

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

44986

Due Date By

Revision I 13 14

79 months

79 months

79 months

79 months

79 months

79 months

79 months

Risk Exposure Period

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Status

Date: 23/05/2017 15 16 17 Remarks

999

999

999

999

T309/CNSS

Vector Management T309/CNSS

T309/CNSS

Mobilization T309/CNSS

018

017

016

015

NA

NA

NA

NA

Traffic Diversion

Workers working on site

Setting up of Hoarding

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

5 Hazard Cause

Risk associated with Traffic Diversion -Unsafe traffic conditions, accident hot spot and vehicles crashing into site -Damaged to UG services -Noise and dust pollution

Transmission of Dengue and Zika

Mosquito bites on construction/ public personnel

6

- Collapse of temporary works - Excessive movement / Collapse of adjacent structures - Injury or fatalities of public and construction workers

Impact

- Transfer (delivery and lifting) material, plant and manpower -Inadequate signage and poor traffic control measures -Unsafe traffic layout -Failure to carryout trial trench for UG services -Failure to barricade work area and provide banksman to guide vehicular movement on site -Failure to equip with proper PPE

- Mosquito breeding - Mosquito bites

- Mosquito breeding - Mosquito bites

- Traffic jam - Injury to public or construction personnel - Claims - Delays

- Injury or fatality of public or construction personnel - Claims - Delays

- Injury to public or construction personnel - Claims - Delays

- Collapse of temporary works - Incorrect information on adjacent structures - Not identifying the behaviour and response of - Damage to own and public properties (Claims) the ground and adjacent structures

Hoarding structural failure -Flawed design of temporary works - Inappropriate use / misinterpretation of design codes - Lack of understanding of design software and output - Temporary works design is incompatible with adjacent structures

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Package 1 7

IV

IV

IV

IV

IV

F

II

I

I

II

II

S

C

B

B

C

C

Ri

Initial Risk Category Ri

8

- Code of Practise of Traffic Control and Work Zone - Use of barrier and/or gate guards for exit/entrances to site -Approval of temporary traffic diversion layout by TM -Traffic layout and signage to follow TCP -Submit PSR (road) for clearance -Ensure good visibility of signage --Apply permit to dig prior to start work -Conduct RA/ SWP briefing -Desk top study of all utilities and carryout appropriate trial trench -Barricade work area and provide proper signage and warning to motorist and pedestrian. -Lane closure to avoid peak hours, applicable hours is 9:30-16:30 for daytime and 16:30-09:30 for night time closure

- Pest control '- Emergency Response planning - Vector control management - Additional supervision - Oiling in stagnant water and other respective areas - Provision of insect repellents to site staff

- Pest control - Emergency Response planning - Vector control Management - Additional supervision - Oiling in stagnant water and other respective areas - Provision of insect repellents to site staff

- Perform further structural or geotechnical investigations e.g. coring, trial trenching

- Sensitivity of design input parameters - Engage experienced and competent consultant to do the design - Engage experienced and competent contractor - Pre-qualify contractor

Mitigation Measures

IV

V

V

V

V

F

II

I

I

II

II

S

C

C

C

C

C

Ri

Residual Risk Category Rr

11 Risk Owner

JHZH-PM

JHZH-PM

JHZH-PM - Properly traffic control and signages with qualified traffic marshal - Clearly defined zones for accessible pathways and restricted areas - Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan - Emergency Response planning including Contingency planning, inspection and monitoring - Lifting zone to be barricaded before works commence - Placement of cone or barrier during diversion without reduction in lane width -Flow chart indicating the flow of instruction enabling the lorry truck to enter the lane closure work area during soil removal or delivery of materials.

- Regular inspection of site to identify and eliminate breeding sites - Misting

- Regular inspection of site to identify and eliminate breeding sites - Misting

JHZH-PM - Strengthening of hoarding when necessary - Additional site investigations and localized ground improvement when necessary - Emergency Response planning including Contingency planning e.g. stop all excavation, ensure safe escape route for workers, additional temporary struts.

JHZH-PM - Engage experienced and competent consultant to perform the design - Engage experienced and competent contractor - Emergency Response planning including Contingency planning e.g. stop all excavation, ensure safe escape route for workers, additional temporary struts.

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

12

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

*Action Owner

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

Due Date By

Revision I 13 14

79 months

79 months

79 months

79 months

79 months

Risk Exposure Period

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Status

Date: 23/05/2017 15 16 17 Remarks

999

T309/CNSS

020

019

N.A

NA

Lifting with crane

Lifting with crane

4

5

- Breakage of lifting chain - Breakage of lifting sling - Failure of brake motor/gear - Failure of sling/chain buckles and hooks - Overloading of carried loads over limited of design capacity - Unauthorized modification of lifting points

Hazard Cause

- Improper securing of material/ equipment - Overloading of material/ equipment - Slight tilt in crane '- Sudden movement of crane boom

Sharp edge material being - Site personnel cut by sharp material during lifted/ lowered/ handled handling

Failing of loose material/ equipment

Crane topple / Hoisted load - Poor crane footage hit crane - Incompetent lifting team - Poor lift plan - Congested work environment

Failure of lifting mechanism

Hazard

Note * - Action Owner will be reassigned from PM to Engineer-in-Charge when respective Engineer-in Charge is established

999

T309/CNSS

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running Code number

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

7

- Injury and fatality to construction personnel - Delays - Claims

I

II

IV

IV

I

IV

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

I

S

IV

F

C

B

B

B

Ri

Initial Risk Category Ri

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

Impact

Package 1 8

- Store all sharp material into material cages when possible - Pack/ organize sharp material - Use of PPE (e.g appropriate safety gloves, long sleeves, helmet and safety boots and glasses)

- Approved PTW (e.g lifting) daily before commencement of work - Lifting Supervisor to ensure correct method of usage - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Avoid loading and unloading near edge of properties or access walkways - Low speed in lifting and lowering of material '- Signaller to communicate with crane operator during lifting and lowering operation - Lifting points to be marked, identified and approved - Approved Lifting plan - Material shall be stacked safely and within stacking limit and load

- Design and COS crane access - No Overloading at all times - Proper mainyenance of crane - Only competent lifting team is allowed - Implemet Permit to lift - Include both Max. and Min load radius - Do not conduct lifting in congested work environment. - Provide exclusion zone and Provide warning signs. - Provide sufficient tag lines

- Apply PTW (e.g. lifting) daily before commencement of work - Monthly inspection of lifting mechanisms - Lifting Supervisor to ensure correct method of usage - Colour coding all lifting mechanisms for validity and serviceability levels - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Lifting points to be identified and approved - Approved Lifting Plan

Mitigation Measures

I

II

IV

I

V

V

I

S

V

F

C

C

C

C

Ri

Residual Risk Category Rr

11

12

JHZH-PM

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

- '- Identify sharp material and dipose (e.g. nails, JHZH-PM broken glasses) - Wrap sharp edges when possible

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

*Action Owner

JHZH-PM

Risk Owner

JHZH-PM

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting - Guidance by traffic controller - Familization course for operator

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

Future Actions

PREPARED BY LEE/ HUA KWAN JONG 9 10

Diaphragm wall, bored piles, ground improvement and enabling works TOMMY

Risk Register

Oct-17

Mar-23

Oct-17

Mar-23

Due Date By

Revision I 13 14

13 months

79 months

13 months

79 months

Risk Exposure Period

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Status

Date: 23/05/2017 15 16 17 Remarks

18th May 2017

3 Months Programme Look ahead Risk and Mitigation

Construction of Siglap Station Thomson‐East Coast Line

Contract T309

2) To identify the major risk hazards and elaborate the mitigation measures in this  workshop

1) To identify the major works activities for the next three months, Jun 2017 – Aug 2017

Objectives of this workshop:

Noise Barrier installation Slab over drain works Utility Corridor Installation Road Works  Traffic diversion 1C Sheet pile installation

Entrance C

Guide Wall & D‐Wall construction Test bore pile

3

Recharge Well Installation

Guide Wall & D‐Wall construction

Cooling Tower / Main Station

Guide Wall & D‐Wall construction Noise Panel installation near to Laguna Park

Demolition and back filling of old drain Guide Wall  Mobilisation of D‐wall rig D‐Wall construction

Entrance B

Entrance D

Entrance A

Upcoming Works Jun 17 – Aug 17

Traffic diversion 1C

Sheet Piling work

Slab over drain Construction

Noise Barrier installation

Entrance C Hoarding Installation

Works at Ent. C

Traffic  Diversion

Activity

Poor planning

Hazard Cause

Noise 

Complaints  from  stakeholder

Traffic jam /  congestion

Lack of  coordination

Workers hit by  Lack of  traffic communication

Motorist  confusion

Public  confusion

Risk

Risk mitigation

Traffic diversion – 1C

Apply for lane closure Close lane in accordance with COP Traffic control Put up sufficient advance warning signage

• •

parties on personnel on process of diversion.

Briefing session to be conducted with all relevant 

parties

Organise “work session” to brief all relevant 

LTA

Coordinate closely with relevant authority e.g. 

•

•

•

•

Sufficient and clear  notification signage to 

• motorist – e.g. VMS

Clear and advance notification to all stake holders

•

Mitigation Measure

Hari (ES Engineer) Jay Cel (JV Site Engineer)

•

Jay Cel (JV Site Engineer)

Jay Cel (JV Site Engineer)

Jay Cel (JV Site Engineer)

•

•

•

•

Jay Cel (JV Site Engineer)

Jay Cel (JV Site Engineer)

• •

Erin (JV SPRO)

•

Action Owner

Traffic  Diversion

Activity

Noise

Complaints  from  stakeholder

Traffic jam /  congestion

Lack of  coordination •

•

Inform NEA about late traffic diversion work 

•

Workers hit by  Lack of  communication traffic

Carry out traffic diversion off peak hours.

•

Poor planning

Motorist  confusion

batons

Traffic controllers to equipped with light 

Ensure workers put on reflective vest.

– Potential noise issue

start

Brief TCP to all relevant person prior work 

Mitigation Measure •

Hazard Cause

Public  confusion

Hazard 

Risk mitigation

Traffic diversion – 1C

•

Hari (ES Engineer)

Mike (JV Safety)

Arron  (JV ECO)

• •

Jay Cel (JV Site Engineer)

Jay Cel (JV Site Engineer)

•

•

Action Owner

Notification via eRMS with the help of LTA project team

Mitigation measures: Communication ‐ Authority

Traffic diversion – 1C

Notification to relevant authority

LTA communication with Main contractors

Mitigation measures: Communication – LTA / Main Contractors  /Sub contractors

Traffic diversion – 1C

Contractors communication

Main contractors to stake holders

Mitigation measure: Communication – Stakeholders/residents

Traffic diversion – 1C

Briefing to stakeholders

Presentation to Laguna Park Residents 

Mitigation measure: Communication – Laguna Park resident

Traffic diversion – 1C

Information will change accordingly

Mitigation measure: Communication – Motorist 

Traffic diversion – 1C

Alert motorist using traffic marshaller

Mitigation measure: TCP ‐ Traffic Closure

Traffic diversion – 1C

Deployment of APO at strategic location for traffic controls

Mitigation measure: Traffic Closures ‐ Auxiliary Police Officers

Traffic diversion – 1C

Guide Wall & D‐Wall construction Recharge Well Installation

Cooling Tower

Cooling Tower Works

“A’ frame  topple

Recharge  well work

Fingers / hand  caught in  rotating parts

Injury to public

Risk 

Activity

Incompetent  crew

Poor ground  condition

Poor footage

Poor  mobilization  planning

Hazard  Cause

4) Recharge Well work – Risk mitigation

• •

• •

• •

•

‐ ‐

‐ ‐

‐ ‐

‐

JV Lift Engineer Sub‐con lifting supervisor

Sub‐con supervisor Sub‐con supervisor

Sub‐con supervisor Sub‐con supervisor

Sub‐con Engineer

JV Superintendent JV Supervisor

‐ ‐

• • Ensure work assess is planned. Ensure adequate access for work mobilisation  and public access. Only competent lifting crew is allowed to  involved in mobilisation. PTW‐Lifting approved prior unloading. Provide proper exclusion zone to segregate  work and public. Provide warning signs. Provide blinker lights to alert night motorist  and /or pedestrian. Ensure footage is firm and level at all times. Never drag load. Lift vertically.

Action Owner

Mitigation Measure

4) Recharge Well work – Risk mitigation

End

12th July 2017

3 Months Programme Look ahead Risk and Mitigation

Construction of Siglap Station Thomson‐East Coast Line

Contract T309

2) To identify the major risk hazards and elaborate the mitigation measures in this  workshop

1) To identify the major works activities for the next three months, Jul 2017 – Sep 2017

Objectives of this workshop:

Guide Wall & D‐Wall construction

Entrance C

Guide Wall & D‐Wall construction

3

Cooling Tower D‐Wall construction Recharge Well Installation Excavation

Noise Panel installation near to Laguna Park Hoarding Shifting Installation Guide Wall & D‐Wall construction

Guide Wall & D‐Wall construction

Entrance B

Entrance D

Entrance A

Upcoming Works Jul 17 – Sep 17

Guide Wall & D‐Wall construction

Entrance A

Works at Ent. A

D‐ walling work

1) Guide wall / D‐ wall excavation

Works at Ent. A

Guide wall in progress

Damaged to :

Excavation  works

Insufficient  marking on  site.

Unplanned  Drilling.

Hazard  Cause

Permit to work system

Water pipe. Power grid  cables.

Risk 

Activity

•

Trial Trench

LCDW  Carry out  cable  detection

‐

Soheal

TBM briefing

Tan WC (JV UE) LCDW Tan WC (JV UE) Thiha Soheal

‐ ‐ ‐ ‐ ‐

• • • • • Thorough study of utilities drawings Cable detections by qualified LCDW Provide clear utilities marking on site Provide A3 size drawing of utility plan Apply permit to dig and implement “checklist  for working near utility” Barricade work area while trenching

Action Owner

Mitigation Measure

1) Guide wall / D‐ wall excavation – Risk mitigation

Works at Ent. A

Damaged to :

Excavation  Works

Telecom  cables. High tension  cables.

Hazard 

Activity

•

•

•

• • • • ‐ ‐ ‐ ‐ ‐

‐ ‐ ‐ ‐

Tan WC Soheal Soheal Soheal Jeremia / Peter

Soheal Soheal Soheal Jeremia (HSL) / Peter (JV)

Tan WC (JV UE)

‐

• Contact relevant utility agency for any  presence of unidentified utility Always treat utility as `live’ if encountered Only manual digging allowed for trial trench Full time supervision during trial trench  ‐No mechanical digging within 3m from  identified utilities. ‐Brief utility plan in language understood by  the workmen. ‐Provide watch man to watchout for utilities  during excavation ‐Senior staff to be involved in site inspection  prior to PTW approval.

Action Owner

Mitigation Measure

Mark out detected cable clearly on site.  Drill only when identified cables are exposed.  Utilities marker are only allowed to shift or remove unless approved by JV UE.

Only manual  excavation is  allowed for  trial trench  works

Failure to  conduct  detection  test.

Hazard  Cause

1) Guide wall / D‐ wall excavation – Risk mitigation

Works at Ent. A

D‐wall work  (Lifting  Work)

Activity

Crane hit surrounding structures, e.g. silo

Crane Toppling

Risk 

•Load hit onto crane

•Instability of working platform

•Failure of loose material equipment/ rebar cages

Hazard Cause

1) Guide wall / D‐ wall excavation – Risk mitigation

Works at Ent. A

‐

Sufi

Omar

‐ • Look into min load radius when hoisting bulky items e.g. rebar cage. •Only R/S can give signal. Trade supervisor cannot involved in lifting work.

Junaet

Sufi

Bok Soon Sufi

‐

‐

‐ ‐

•Signaler to communicate with crane operator

•Safety zone established

•Material shall be stacked safely and within stacking limit and load

•Low speed in lifting and lowering

Gajan

Killi

‐

•Approved lifting plan, reviewed by LE and approved by PM

‐

Sufi

‐

•Lift load by 300mm, stabilized for 3 seconds.

•Lifting points to be identified and approved

Action Owner

Mitigation Measure

Side View

Ground

“L” shaped D‐wall panel

Plan View

6.5m

9

1) Guide wall / D‐ wall excavation – Risk mitigation (“L” Shaped panel

Works at Ent. A

Normal D‐wall panel

Risk 

Tandem lift  Crane collapse work (“L”  shape  panel) Workers hit by  fallen objects  from D –wall

Activity

• •

•

•

Loose  • material on D‐ • wall panel •

10

Designed and COS crane access. Approved Permit to Lift. Approved lift plan. Valid and adequate lift gears for taking weight  of D‐wall panel. Provide adequate tag lines. Identify proper hooking point for turning D‐ wall. Only one LS to control tandem lift. Standing supervision by LE. Ensure lifting activities not carried out in  congested work area. Ensure no loose material on D wall panel prior  lifting. Provide exclusion zone and warning sign to  prevent unauthorised entry. Tandem lift to be carried out during day shift. No obstruction of LS/CO view at all times.

Mitigation Measure

Unplanned lift • • • Over loading  • due to poor coordination  • between  LS •

Hazard  Cause

1) Guide wall / D‐ wall excavation – Risk mitigation

Works at Ent. A

‐ ‐

‐

‐

JV Superintendent – Peter HSL LS

HSL LS Ahmed Sufi

HSL LS Ahmed Sufi

JV Lift Engineer Killi JV Lift Engineer killi JV Superintendent – Peter

HSL LS Ahmed Sufi JV Engineer Desi

‐ ‐ ‐ ‐ ‐

LV lift Engineer Killi JV Project Manager ‐ Frank JV Project Manager ‐ Frank HSL LS Ahmed Sufi

‐ ‐ ‐ ‐

Action Owner

Hand finger  injuries /  Amputation

Stitching   D‐wall (“L”  shape  panel)

Workers fall  into d‐wall  trench

Risk 

Activity

‐

‐ ‐

11

Designed stopper for resting D wall cage All personnel to cleared at least 3 meters away  during lowering of stitched D‐wall. Do not start stitching rebar cage until rebar  cage is fully rested on stopper. Always keep hand away from line of fire. Provide proper barricades and warning sign  around D—wall trench.

Mitigation Measure

‐ D‐wall stiches  ‐ tear due to  poor  coordinated  lift

Uncontrolled  movement /  poor  coordinated lift.

Hazard  Cause

1) Guide wall / D‐ wall excavation – Risk mitigation

Works at Ent. A

‐ ‐

‐

‐ ‐

HSL Supervisor – Soheal HSL Supervisor‐ Soheal

HSL Supervisor – Soheal

JV Engineer – Desi HSL Supervisor Soheal

Action Owner

D‐wall work  (Grabbing Work)

Activity

Utility damage

Grabber hit surrounding structures, e.g. silo

•Instability of working platform

Grabber Toppling

•Inadequate supervision and control

•Lack of communication

•Failure of loose material equipment/ rebar cages

Hazard Cause

Risk 

1) Guide wall / D‐ wall excavation – Risk mitigation

Works at Ent. A

•Banksmen to guide crawler crane movement, ensuring no tracking over drain, trench or uneven ground.

•Lifting operation supervised by lifting supervisor

•Approved lifting plan, reviewed by LE and approved by PM

•Signaler to communicate with crane operator

‐

‐

‐

Junaet

Sufi

Frank

Soheal

Soheal

‐

•Put in place the excavation permit system and display the relevant details on site.

‐

Peter

‐

•Provide adequate hardstanding /firm working platform

•Ensure no overloading of grabber

Action Owner

Mitigation Measure

Provide barricade around grabbing work

1) Guide wall / D‐ wall excavation – Risk mitigation

Works at Ent. A

Heavy machine on steel plate

PTW –lifting system is established

Approved Lift Plan

1) Guide wall / D‐ wall excavation – Risk mitigation

Works at Ent. A

Lifting supervisor checking the checklist of operator

Low speed in lifting and lowering

Lifting points to be identified and approved

Approved lifting plan

Lift load by 300mm, hold for 3 seconds

Provide Valid  Fire extinguisher

1) Guide wall / D‐ wall excavation – Risk mitigation

Works at Ent. A

Safety zone established

Material shall be stacked safely and within stacking limit and load

Heavy machines mobilization  process guided by TC, supervised by  engineer, supervisors and safety  personnel

1) Guide wall / D‐ wall excavation – Risk mitigation

Works at Ent. A

Approved lifting plan for all lifting on site

Pre‐start briefing in language understood by workmen prior lifting work.

1) Guide wall / D‐ wall excavation – Risk mitigation

Works at Ent. A

LM Machine not up to expectation will tagged “Not Safe for Use”

1) Guide wall / D‐ wall excavation – Risk mitigation

Works at Ent. A

Weekly boom down inspection with mechanics

Guide Wall & D‐Wall construction

Entrance B

Works at Ent. B

Guide wall and D‐wall construction work at Ent. B

Works at Ent. B

Guide Wall & D‐Wall construction

Entrance C

Works at Ent. C

Noise Panel installation near to Laguna Park

Guide Wall & D‐Wall construction

Hoarding Shifting Installation

Entrance D

Works at Ent. D

Works at Ent. D

D‐ walling at Entrance D

Guide Wall & D‐Wall construction Recharge Well Installation Excavation Work

Cooling Tower

Cooling Tower Works

Cooling Tower Works

Area of excavation

Excavation  work

Activity

Fall into  Excavation

Excavation  Collapse

Risk 

•

Incompetent  crew

Poor ground  condition

•

• •

• •

‐

‐ ‐

‐ ‐

‐ ‐

‐

Gajan

Killi Sufi

Soheal Soheal

Soheal Soheal

Thiha

Peter Thomas

‐ ‐

• • Ensure work assess is planned. Ensure adequate access for work mobilisation  and public access. Only competent excavation crew is allowed to  involved. PTW‐Excavation approved prior activity. Provide proper exclusion zone to segregate  man and machines. Provide warning signs. Provide blinker lights to excavator and proper  lighting particularly for night work. Ensure footage is firm and level at all times. Provide proper design and COS for shoring or  sloping. No stock pipe of spoil at site. To cover with  canvas in case of 

Action Owner

Mitigation Measure

• Poor Shoring /  • Sloping

Poor Planning

Hazard  Cause

3) Excavation work (Cooling Tower) – Risk mitigation

Recharge  well work

Activity

Fingers / hand  caught in  rotating parts

Injury to public

“A’ frame  topple

Risk 

Incompetent  crew

Poor ground  condition

Poor footage

Poor  mobilization  planning

Hazard  Cause

3) Recharge Well work – Risk mitigation

• •

• •

• •

•

‐ ‐

‐ ‐

‐ ‐

‐

Killi Sufi

Soheal Soheal

Soheal Soheal

Thiha

Peter Thomas

‐ ‐

• • Ensure work assess is planned. Ensure adequate access for work mobilisation  and public access. Only competent lifting crew is allowed to  involved in mobilisation. PTW‐Lifting approved prior unloading. Provide proper exclusion zone to segregate  work and public. Provide warning signs. Provide blinker lights to alert night motorist  and /or pedestrian. Ensure footage is firm and level at all times. Never drag load. Lift vertically.

Action Owner

Mitigation Measure

• Noise ‐ Noise monitoring of activities throughout operations

• Vibration ‐ 24/7 monitoring of vibration/ground movements

• Dust ‐ Spraying of water as a dust suppression activity ‐ Use of erosion control blankets

Examples

Other Mitigation Measures

End

Minutes Title: Monthly Risk Register Workshop No 6 Date:12 Jul 2017 Time: 2.00pm--3.30pm Held at: T306 Meeting Room

Chaired by: Jong Hua Kwan/ Tommy Lee Minuted by: Tommy Lee Distribution date: 17 Jul 17

Attendees list See attached

Apologies list

Page 1 of 3

Minutes ITEM

MATTERS DISCUSSED

1.0

Introduction

ACTION

Risk Workshop will be on Guide Wall/ D-wall excavation, L-shape panel lifting, excavation works was submitted.

Info

The complete flow of the process will be demonstrated via a short slide presentation The project superintendent will provide the necessary information required to mitigate risks on the above.

2.0

Slide presentation on 3 monthly look ahead - Jul - Sep 17

Peter/ Jong

2.1

DD asked in relation to the incident where the LV cable was hit, if trial trench was carried out. JHZH replied that for all future trial trench, JHZH will co-sign on the trial digging and excavation permit.

Note

2.2

DD informed to include positive identification of utilities under utilities risk in risk register.

JHZH

2.3

2.4

T309P informed to include ramp specification for loading/unloading of heavy machinery. JHZH will amend the Safety Plan to include this information.

DD highlighted the importance of using several languages in the workforce and commended JHZH on the good practise.

JHZH

Note

2.5

T309P asked about the sequence of the two crane lifting of the L-shape D-wall panel. T309P had shared the experience of the tandem lift for T308 with JHZH. DD suggested to have a working session on this discussion.

JHZH

2.6

DD commended on the good practise of steel plate placement within site. However, maintenance of the steel plate level and checking out the compactness of the ground are important. On regular basis, JHZH will top up the ground with mill waste.

JHZH

2.7

JHZH

DD/T309P informed JHZH to maintain the risk register and treat it as a live document and constantly update it. 2.8

T309P informed that the action owner shall be specific personnel to be included in the risk register.

2.9

JHZH

JHZH

Page 2 of 3

Minutes ITEM

MATTERS DISCUSSED

ACTION

2.10

T309P informed that to include sub-con mechanic and supplier mechanic in performing equipment functionality when the need arises.

JHZH

2.11

T309P asked to highlight the closed and new risks for the next monthly risk meeting.

JHZH

DD asked for programme risk to be included separately. T309P asked for instrumentation and monitoring risk to be included in subsequent risk register.

3.0

Any Other Matters: The next workshop topic will be proposed accordingly.

4.0

INFO

Next Workshop The next monthly workshop will be discussed with T309P for a proposed date

Page 3 of 3

All / Info

T309/CNSS

T309/CNSS

100

100

ERSS for Temporary Work

008

007

T309/CDSS/100/008

T309/CDSS/100/007

Trenching

Lifting with crane

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

Instability of temporary works (trenches)

● Differential settlement between station ERSS ● Failure of loose material, equipment/ rebar cage ● Instability of working platform

Hazard

4

5 Hazard Cause

ERSS wall construction within F1 soil layer - F1 soil layer collapse - Trench stability

- Not identifying the behaviour and response of the ground and adjacent structures

Flawed design of temporary works - Inappropriate use / misinterpretation of design codes - Lack of understanding of design software and output - Incorrect information on adjacent structures - Temporary works design is incompatible with adjacent structures

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Doc no: T309-JHZH-RAR-PWD-RIS-0001

6

- Collapse of temporary works - Excessive movement/Collapse of adjacent structures - Injury or fatalities of public and Construction workers

- Collapse of temporary works - Collapse / damage of adjacent structures - damage of permanent works - Injury or fatality of construction workers or public

Impact

Risk Classes A 0 B 23 C 59 D 7 89

Package 1

V

V

V

F

7

I

I

I

S

C

C

C

Ri

Initial Risk Category Ri

8

- Contractor to produce robust design - Appropriate design sensitivity - Specify minimum penetration of panels - Additional site investigation - Pre-qualify contractors - Emergency Response planning - Provide temporary strut with PE endorsement

- Review levels to be developed - Regular review of Instrumentation / monitoring e.g. LBs to monitor building movement, LGs for ground movement and IW or XYZ for ERSS. - Approved Permit to lift and lifting plan - Lifting Supervisor to ensure correct method of usage - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Avoid loading and unloading near edge of properties or access walkways - Low speed in lifting and lowering of material '- Signaller to communicate with crane operator during lifting and lowering operation - Lifting points to be identified, marked and approved

- Contractor to produce robust design - Approved Permit to lift and lifting plan - Lifting Supervisor to ensure correct method of usage - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Avoid loading and unloading near edge of properties or access walkways - Low speed in lifting and lowering of material '- Signaller to communicate with crane operator during lifting and lowering operation - Lifting points to be identified, marked and approved

Mitigation Measures

I

I

V

V

I

S

V

F

C

C

C

Ri

Residual Risk Category Rr

11

12

JHZH-PM - Regular review instrumentation reading - Perform probing and SI (SPT) at regular intervals - Perform Ground Improvements when necessary - Joint inspection between JHZHJV and QPS for every Dwall 1) Mild case (to read; less than 10% of total panel excavated volume) – Create an earth bund wall surrounding the affected panel, fill up the bund wall pool with bentonite to increase the bentonite head level. 2) Moderate case (to read; more than 10% of total panel excavated volume, without any visual ground/ platform depression) – Move the grabber and other unnecessary heavy equipment at least 20m away from the affected panel, and backfill the panel with LSS to the ground level by tremie method. 3) On a case by case basis for a severe case (to read; more than 10% of total panel excavated volume, with obvious visual ground/ platform depression) – Move all machinery away except excavator at least 20m away from the affected panel, and backfill the panel with LSS to the ground level by tremie method. After 24 hours of backfilling, conduct light cement grout beneath the depressed platform.

JHZH-PM

JHZH-PM

- Steel plate to ensure uniform loading of crane JHZH-PM weight and outrigger - Use of level indicator and inclinometer - Additional site investigation when necessary - Lifting zone to be barricaded before works commence 1) Mild case (to read; less than 10% of total panel excavated volume) – Create an earth bund wall surrounding the affected panel, fill up the bund wall pool with bentonite to increase the bentonite head level. 2) Moderate case (to read; more than 10% of total panel excavated volume, without any visual ground/ platform depression) – Move the grabber and other unnecessary heavy equipment at least 20m away from the affected panel, and backfill the panel with LSS to the ground level by tremie method. 3) On a case by case basis for a severe case (to read; more than 10% of total panel excavated volume, with obvious visual ground/ platform depression) – Move all machinery away except excavator at least 20m away from the affected panel, and backfill the panel with LSS to the ground level by tremie method. After 24 hours of backfilling, conduct light cement grout beneath the depressed platform.

*Action Owner

JHZH-PM

Risk Owner

- Steel plate to ensure uniform loading of crane JHZH-PM weight and outrigger - Use of level indicator and inclinometer - Additional site investigation when necessary - Emergency Response planning including Contingency planning e.g. stop all excavation, ensure safe escape route for workers, additional temporary struts. - Lifting zone to be barricaded before works commence - Lift load by 300mm, hold for 3 seconds, all personnel 3m away Approved lifting plan, reviewed by LE and approved by PM - Lifting points to be identified and approved - Low speed in lifting and lowering - Material shall be stacked safely and within stacking limit and load - Safety zone established - Signaler to communicate with crane operator

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10

Summary of Residual Risk Classes A 0 B 0 C 74 D 15 89

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

The Risk Register is a "live document" and it will be the responsibility of all parties involved in the design, construction and commissioning of the T309 Initial Project and to ensure that all reasonable means and measures are put in place for the effective management of all the safety risks.to continue to identify new risks that arises.

e

Apr-17

Apr-17

Apr-17

Due Date By

Revision J 13 14

7 months

7 months

7 months

Risk Exposure Period

C

C

C

Target Risk Rating

Open

Open

Open

Status

Date: 11/08/2017 15 16

17 Remarks

011

012

100

100

T309/CNSS

T309/CNSS

T309/CDSS/100/012

T309/CDSS/100/011

T309/CDSS/100/010

010

100

T309/CNSS

T309/CDSS/100/009

009

100

T309/CNSS

Construction of ERSS for Utility Diversion

Construction of ERSS for Drain Diversion

Construction of ERSS

Construction of ERSS

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

Instability of temporary works (Utility Diversion ERSS)

Instability of temporary works (Drain Diversion ERSS)

Excessive ground movement of adjacent structures and utilities

Instability of temporary works (ERSS failure)

Hazard

4

5 Hazard Cause

6 Impact

Structural damage/deflection of existing structures - Damage to utilities - Traffic accidents with associated injuries - injuries to public or construction workers associated with ramp distress - Damage to road surfaces - Wall toe movement

- Damage to utilities - Damage to road surfaces

-Higher than expected lateral deflection of ERSS wall during excavations - Unforeseen ground conditions - Inappropriate removal of struts - Over-excavation - Excavation for the utilities laying/trench

- Unforeseen higher than designed surcharge

- Damage to utilities - Damage to road surfaces

- Unforeseen higher than designed surcharge

IV

IV

III

III

III

III

IV

- Injuries to public or construction workers associated with ramp distress - Traffic accidents with associated injuries - Structure Integrity of sheet piles.

- Inappropriate removal of struts - Over-excavation - Excavation for the drain and damage ERSS - Sheet pile obstructed and not able to pile into required depth. -Poor quality weld and design of sheet pile bracing.

IV

III

III

III

IV

IV

IV

I

I

V

V

I

I

S

V

V

F

7

C

C

C

C

C

C

C

C

C

C

C

Ri

Initial Risk Category Ri

- Structural damage/deflection of existing structures - Damage to utilities - Injuries to public or construction workers associated with ramp distress - Damage to road surfaces - Wall toe movement

Structural damage/deflection of existing structures - damage to utilities - Traffic accidents with associated injuries - injuries to public or construction workers associated with ramp distress - damage to road surfaces - Wall toe movement

Package 1

- PE to ensure surcharge level to within acceptable loading

- Contractor to produce robust design - Method Statements to ensure safe working methods - Monitoring on site - Gather knowledge from people with relevant experience - Visual inspection

- PE to ensure surcharge level to within acceptable loading

- Method Statements to ensure safe working methods -Follow the PTW (e.g excavate) daily during work - Review design of sheet pile and provide COS. - Only certified and appointed welders are allowed to weld. - Method statement to ensure proper bracing is provided.

- Contractor to produce robust design - Method Statements to ensure safe working methods - Gather knowledge from people with relevant experience

- PE to ensure surcharge level to within acceptable loading

- Contractor to produce robust design - Method Statements to ensure safe working methods -Regular review instrumentation reading - Apply PTW (e.g. excavate) daily before commencement of work

- Calculate amount of bentonite level required

- Robust Contractor's ERSS system - Pre-qualify contractors

- Contractor to produce robust design - Appropriate design sensitivity

- Contractor’s Method Statements - Apply PTW (e.g. excavate) daily before commencement of work '- Emergency Response Planning including Contingency planning e.g. grouting of gaps - Additional site investigation

Mitigation Measures

8

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

-Higher than expected lateral deflection of ERSS wall during excavations - Unforeseen ground conditions

- Unforeseen higher than designed surcharge

Higher than expected lateral deflection of ERSS wall during excavations - Unforeseen ground conditions - Inappropriate removal of struts - Over-excavation - Excavation of cut and cover tunnel

- Low bentonite level

Inadequate structural detail connection between - Collapse of temporary works strut, waler to ERSS walls / shafts / excavations - Excessive movement/Collapse of adjacent structures - Injury or fatalities of public and Construction workers - Contractor's ERSS design - Workmanship

- Groundwater drawdown

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

V

V

III

III

III

III

V

V

III

III

III

I

I

V

IV

IV

V

V

I

I

V

V

S

F

D

D

D

D

D

C

C

C

C

C

C

Ri

Residual Risk Category Rr

11

- No stockpiling

JHZH-PM

-Provide ground improvements when necessary JHZH-PM - Requirements to record penetration into competent stratum on installation -High quality site records -Bearing capacity checks for construction equipment - Installation of additional recharge wells & pressure relief wells as contingencies.

- No stockpiling

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM - instrumentation/monitoring to monitor strut loads. - Daily physical inspection of strutting system

JHZH-PM

JHZH-PM

JHZH-PM -Statutory requirement for QP(Sup) to be responsible for supervision of temporary works. -Emergency Response planning including Contingency planning

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

-Normal/ established procedures for staging the JHZH-PM works to protect adjacent utilities -Permit to remove strut system followed to prevent inappropriate removal of struts -Emergency Response planning including Contingency Planning

- No stockpiling

12 *Action Owner

JHZH-PM

JHZH-PM

Risk Owner

- Control of excavation opening to pouring time JHZH-PM

- High quality construction records - Ensure trench stability - Emergency Response planning

- instrumentation/monitoring to monitor strut loads. - Daily physical inspection of strutting system

-Emergency Response planning including Contingency planning -Instrumentation/monitoring to monitor strut loads. - Instrumentation/ real time monitoring - Perform probing and SI (SPT) at regular intervals - Sufficient vibration monitors with appropriate trigger levels to be installed. - Provision of recharge wells. -Provide proper recharging system -Provide proper filter gravel

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10

Apr-17

Oct-17

Apr-17

Apr-17

Apr-17

Apr-17

Apr-17

Apr-17

Apr-17

Apr-17

Mar-17

Due Date By

Revision J 13 14

7 months

13 months

7 months

7 months

7 months

7 months

7 months

7 months

7 months

7 months

7 months

Risk Exposure Period

C

C

C

C

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Open

Open

Open

Open

Status

Date: 11/08/2017 15 16 17 Remarks

T309/CNSS

T309/CNSS

100

100

014

013

N.A

NA

Construction of ERSS (Kingpost) for traffic decking

Construction of ERSS (Drainage diversion)

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

- Instability of temporary works (kingpost for traffic decking - ERSS) -Poor ground condition -Using of poor condition machinery - Noise pollution -Accidental dislodgement of kingpost during driving -Collision of machinery and site people.

Gaps in sheet piles

Hazard

4

5 Hazard Cause

- Poor design lead to undersize kingpost. - Poor workmanship. -Overloading of kingpost with other load not considered in the design. -Toppling of machinery resulting in damage to property. -Injury to surrounding people. -Structure failure of machinery.. -Old machinery and poor maintenance causing disturbance to nearby resident. - Carelessness and inexperience operator. Faulty vibro hammer.

- Supporting structure across the excavation due to lack of diversion corridor

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

- Collapse of temporary works - Collapse / damage of adjacent structures - damage of permanent works - Injury or fatality of construction workers or public

- Leakage through gap in the walls - Damage to services - Groundwater drawdown - Localized collapse of soil in the gap during excavation

Impact

Package 1

IV

III

S IV

F III

C

C

Ri

Initial Risk Category Ri

7

- Method Statements to ensure kingpost is constructed according to MS -JV engineer / QPS to supervise kinghpost construction work to esnure quality of workmanship. - Design to allow sufficient safety factor for structure interity of kingpost. -Access to be laid with hardcore and compacted. -I beam to be properly stacked and excluded. -Machine to be inspected and certified by AE. -Regular monthly maintenance of machineries - Work zone to be barricaded to prevent unauthorized entry - Used of tag line to control swaying of load. - Only allow skilled operator and experienced lifting team.

- Minimize gaps to minimum size required - Utilities diverted from excavation wherever possible - Instrumentation around gap area when necessary

Mitigation Measures

8

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

V

III

S IV

F IV

D

D

Ri

Residual Risk Category Rr

11 Risk Owner

- During construction phase, ensure RA control measure are implemented - e.g. -Segregation of man and machines -Provide designated pedestrian access for wokers. - Provide adequate warning signs. - Provide proper barricades around bore hole. -Installed sound barrier - Used of silent piler - Refrain from working at night and weekend /PH - Additional sling tied to sheet pile and machinery as extra protection in case grabber gives way. - Access to be laid with hard-core and compacted. - kingpost to be laid on top of hard-core.

JHZH-PM

JHZH-PM - Reinstall sheet piles if there are gaps during installation - Emergency Response Planning including Contingency Planning (e.g. immediate removal works upon sighting of unfavaourable ground/wall movements) 1) Mild case (to read; less than 10% of total panel excavated volume) – Create an earth bund wall surrounding the affected panel, fill up the bund wall pool with bentonite to increase the bentonite head level. 2) Moderate case (to read; more than 10% of total panel excavated volume, without any visual ground/ platform depression) – Move the grabber and other unnecessary heavy equipment at least 20m away from the affected panel, and backfill the panel with LSS to the ground level by tremie method. 3) On a case by case basis for a severe case (to read; more than 10% of total panel excavated volume, with obvious visual ground/ platform depression) – Move all machinery away except excavator at least 20m away from the affected panel, and backfill the panel with LSS to the ground level by tremie method. After 24 hours of backfilling, conduct light cement grout beneath the depressed platform.

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10 12

JHZH-PM

JHZH-PM

*Action Owner

Apr-17

Apr-17

Due Date By

Revision J 13 14

7 months

7 months

Risk Exposure Period

C

C

Target Risk Rating

Open

Open

Status

Date: 11/08/2017 15 16 17 Remarks

102

102

102

102

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

102

102

T309/CNSS

T309/CNSS

102

Diaphragm walling T309/CNSS

007

006

005

004

003

002

001

NA

NA

N.A

T309/CDSS/102/004

T309/CDSS/102/003

T309/CDSS/102/002

T309/CDSS/102/001

Barrette pile test

Welding Works with Welding inverter

Welding Works with Oxygen acetylene and Welding inverter

Diaphragm walling

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

5

-Instability of ERSS wall trenches - Low shear strength in Marine Clay - Loose fills - Possible removal of buried obstructions - Presence of thick peaty layers - High pore water pressure in Marine Clay - Close proximity of adjacent activities such as jet grout piles or casting of nearby trench -Leakage of Bentonite from D wall -Poor Bentonite mixe.

Hazard Cause

6

- Structural damage/deflection of existing structures - Damage to utilities - Traffic accidents with associated injuries - Damage to road surfaces - Collaspe of D wall

Impact

Kentledge collapse

- Failure of jack, jack force is not locked in - Unbalance pressure force in jack

- Testing of D-wall

- Improper maintenance of welding set - Improper connection and damaged cables - welding set not fully protected from wet surfaces - Welding in open space during wet weather condition

- Injury to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Injury to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Injury to public or construction personnel - Delays - Claims -Reputation

IV

IV

IV

I

I

I

II

IV

- Injury to public or construction personnel - Delays - Claims - Damage to permanent and temporary works

Fire sparks, fire explosion - Inappropriate welding of struts - Inappropriate welding of Traffic Deck due to Gas leaks, hose damaged, fitting damaged - Inappropriate welding of Noise Barriers - Incompetent welder deployed

Electrocution due to electrical leak

III

V

III

III

V

V

II

S

IV

F

7

B

B

B

C

D

D

D

C

Ri

Initial Risk Category Ri

- Water ingress - Lost toe stability - Loss of fines - Settlement of structures

- Delay of works -Inappropriate diaphragm wall design - Inappropriate use / misinterpretation of design codes

Package 1

- Contractor shall provide -uniform hydraulic pressure supply to all jacks to main balance force in test - Mechanical safe lock (safety valve) to lock pressure in jack during jack operation in case of pressure loss

- Test set up must get endorsement of PE

- PPE: Welding face shield, apron and gauntlet - Apply PTW (e.g. hot works) daily before commencement of work - Electrical wires to be secured above ground - Daily welding set checklist/ inspection - Certified welders - Reminder in Tool box meeting

- PPE: Welding face shield, apron and gauntlet - Proper housekeeping - Method Statements (e.g. - Close main value & flush hose line after usage) - Apply PTW (e.g. hot works) daily before commencements of works - Daily welding set checklist/ inspection - Fire extinguishers and fire blankets - Reminder in Tool box meeting '- Certified welders - Welding screen to contain sparks

- Specifying waterproofing details @ interface

- Use of adequate plant / equipment for diaphragm wall construction -Apply PTW (e.g. lifting) daily before commencements of works - Cage to be within lifting equipment capacity - Lifting points to be identified, marked and approved

- Emergency Response Planning including Contingency planning e.g. grouting of gaps - Method Statements to ensure safe working methods - Apply PTW (e.g. excavate) daily before commencement of work

- Method Statements to ensure safe working methods - Regular monitoring of critical structures - Stability calculations - Contingency planning e.g. (backfilling) in case of collapse, additional temporary struts - Trial panel - Raised guide walls - Control of bentonite properties (e.g. viscosity, sand content, PH value, density) - Visual inspection - Pre-qualify contractors -Apply PTW (e.g. excavate) daily before commencement of work - Deploy worker to monitor Bentonite level especially over week end.

Mitigation Measures

8

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

Inadequate water tightness - Poor concrete compaction - Inadequate concrete cover and reduced durability due to honeycomb - Poor workmanship

Diaphragm wall cage too heavy to be lifted

Gaps in retaining systems Provision for services to pass through retaining -Cracking / leakage systems - Structural Damage - Waterproofing problems and associated repair

Excessive ground movement of adjacent structures and utilities

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

V

V

V

V

V

I

I

I

I

III

III

III

V

V

II

S

IV

F

C

C

C

C

D

D

D

C

Ri

Residual Risk Category Rr

11 Risk Owner

12

JHZH-PM

- Provide physical barrier (interlocked properly) JHZH-PM and safety signs around test sites - Emergency Response planning including Contingency planning - Proper design of kentledge system - Pre-qualify the subcontractor - Approved Method Statement

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

*Action Owner

JHZH-PM

JHZH-PM

-Monitoring of overall settlement and differential JHZH-PM settlement of the kentledge - Provide physical barrier (interlocked properly) and safety signs around test sites - Emergency Response planning including Contingency planning - Proper design of kentledge system - Pre-qualify the subcontractor - Approved Method Statement

-No welding work under rain weather/ wet surfaces - Monthly inspection of welding equipment - Apply Safe Work procedure - Electrical neoprene cable double insulated

- Remove flammable items (timber, canvas etc.. )from welding premises - Monthly inspection of welding equipment - Apply Safe Work Procedure - Implement PTW -Hot work

- High quality construction inspection and records - Method Statements to ensure safe working methods - Use of adequate plant/equipment for ERSS wall construction

- Adopt approved lifting plan - Ensure lifting equipment are inspected monthly - Lifting zone to be barricaded before works commence

- Proper post-cast for structure - Specifying waterproofing details @ interface

-Normal/ established procedures for staging the JHZH-PM works to protect adjacent utilities -Regular review instrumentation reading -Permit to remove strut system followed to prevent inappropriate removal of struts -No stockpiling against D-wall -Emergency Response planning including Contingency planning - Never start D-walling without having the cages ready.

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10

Mar-17

Mar-17

Oct-17

Oct-17

Oct-17

Oct-17

Oct-17

Oct-17

Due Date By

Revision J 13 14

7 months

7 months

13 months

13 months

13 months

13 months

13 months

13 months

Risk Exposure Period

C

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Open

Status

Date: 11/08/2017 15 16 17 Remarks

102

T309/CNSS

102

102

Pilling T309/CNSS

T309/CNSS

102

102

T309/CNSS

T309/CNSS

011

010

009

009

008

NA

T309/CDSS/102/004

T309/CDSS/102/001

NA

NA

Bored pile test

Piling

Lifting with crane

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

5

-Instability of ERSS wall trenches - Low shear strength in Marine Clay - Loose fills - Possible removal of buried obstructions - Presence of thick peaty layers - High pore water pressure in Marine Clay - Close proximity of adjacent activities such as jet grout piles or casting of nearby trench

Kentledge collapse

- Failure of jack, jack force is not locked in - Unbalance pressure force in jack

- Bored Pile testing

Inadequate water tightness - Poor concrete compaction - Inadequate concrete cover and reduced durability due to honeycomb - Poor workmanship

Excessive ground movement of adjacent structures and utilities

- Poor design - Poor workmanship - Poor rigging method

- Improper securing of material/ equipment/ cages - Overloading of material/ equipment/ cages - Slight tilt in crane '- Sudden movement of crane boom

Failing of loose material/ equipment/ rebar cages

In Stability of rebar cage (including cages for Lshape d-wall panel)

- Breakage of lifting chain - Breakage of lifting sling - Failure of brake motor/gear - Failure of sling/chain buckles and hooks - Overloading of carried loads over limited of design capacity - Unauthorized modification of lifting points -Inadequate rigging method.

Hazard Cause

Failure of lifting mechanism

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

- Injury to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Injury to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Water ingress - Lost toe Stability - Loss of fines - Settlement of structures

- Structural damage/deflection of existing structures - Damage to utilities - Traffic accidents with associated injuries - Damage to road surfaces

IV

IV

V

IV

IV

I

I

III

II

I

I

IV

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Injury to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities - Rebar cage fall off during lifting process. - Crane damanged by swing load e.g. windscreen damaged by lifted rebar cage.

I

S

IV

F

7

B

B

D

C

B

B

B

Ri

Initial Risk Category Ri

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities -Crane topple -Tanish reputation

Impact

Package 1

- Contractor shall provide -uniform hydraulic pressure supply to all jacks to main balance force in test - Mechanical safe lock (safety valve) to lock pressure in jack during jack operation in case of pressure loss

- Test set up must get endorsement of PE

- Use of adequate plant / equipment for ERSS wall construction

- Method Statements to ensure safe working methods - Regular monitoring of critical structures - Stability calculations - Contingency planning e.g. (backfilling) in case of collapse, additional temporary struts - Trial panel - Raised guide walls - Control of bentonite properties (e.g. viscosity, sand content, PH value, density) - Visual inspection - Pre-qualify contractors - Apply PTW (e.g. piling) daily before commencement of work

- Cage design must get endorsement of PE - Regular inspection of interface with good records - Lifting points to be marked, identified and approved - Engineer to be present to confirm lifting points prior liftng rebar cage. - Ensure moin load radius is taken into consideration when preparing lift plan.

- Approved PTW (e.g lifting) daily before commencement of work - Lifting Supervisor to ensure correct method of usage - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Avoid loading and unloading near edge of properties or access walkways - Low speed in lifting and lowering of material '- Signaller to communicate with crane operator during lifting and lowering operation - Lifting points to be marked, identified and approved - Approved Lifting plan - Material shall be stacked safely and within stacking limit and load

- Apply PTW (e.g. lifting) daily before commencement of work - Monthly inspection of lifting mechanisms - Lifting Supervisor to ensure correct method of usage - Colour coding all lifting mechanisms for validity and serviceability levels - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Lifting points to be marked, identified and approved - Approved Lifting Plan -Weekly boom down inspection with mechanics

Mitigation Measures

8

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

V

V

V

IV

I

I

III

II

I

I

V

V

I

S

V

F

C

C

D

C

C

C

C

Ri

Residual Risk Category Rr

11

12

JHZH-PM

JHZH-PM

- Provide physical barrier (interlocked properly) JHZH-PM and safety signs around test sites - Emergency Response planning including Contingency planning - Proper design of kentledge system - Pre-qualify the subcontractor - Approved Method Statement

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

*Action Owner

JHZH-PM

Risk Owner

-Monitoring of overall settlement and differential JHZH-PM settlement of the kentledge - Provide physical barrier (interlocked properly) and safety signs around test sites Contingency planning - Emergency Response planning - Proper design of kentledge system - Pre-qualify the subcontractor - Approved Method Statement

- High quality construction inspection and records - Method Statements to ensure safe working methods

- Regular review Instrumentation reading -Permit to remove strut system followed to prevent inappropriate removal of struts - Emergency Response planning - Review SI report and cross check at site - Provide water relief wells when necessary

- Emergency Response planning including Contingency planning - Adopt 3X3 lifting principles. - Only R/S is allowed to give signal to crane operator.

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10

Mar-17

Mar-17

Mar-17

Mar-17

Mar-17

Oct-17

Oct-17

Due Date By

Revision J 13 14

7 months

7 months

7 months

7 months

7 months

13 months

13 months

Risk Exposure Period

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Status

Date: 11/08/2017 15 16 17 Remarks

105

105

T309/CNSS

T309/CNSS

003

002

T309/CDSS/105/003

T309/CDSS/105/002

T309/CDSS/105/001

Adjacent Structures or Buildings T309/CNSS 105 001

NA

T309/CDSS/103/001

103

Permanent Works T309/CNSS

012

001

102

T309/CNSS

Construction work nearby to adjacent structures or buildings

Construction work nearby stake holders

Construction work nearby to school

Construction of Permanent Works

Lifting with crane

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

5

- Breakage of lifting chain - Breakage of lifting sling - Failure of brake motor/gear - Failure of sling/chain buckles and hooks - Overloading of carried loads over limited of design capacity - Unauthorized modification of lifting points

Hazard Cause

- Improper securing of material/ equipment/ cages - Overloading of material/ equipment/ cages - Slight tilt in crane '- Sudden movement of crane boom

Excessive ground and building settlement

Damage / excessive settlement to buildings/structures: - Victoria School Access Bridge - 2-storey semi-detached houses at Kee Sun Ave - St. Andrew's Autism Centre - Elliot at The East Coast - Laguna Park Electrical Substation (Block 5000F) - 2-storey semi-detached houses at Elliot Walk - Opera Estate Canal & Culverts Interface with the public.

Stop or delay school operation. Interface with the public.

- Activation criteria and minimum head are not given

- Ineffectiveness of recharge well layout given in the A/E design '- Some recharge well points will not provide effective recharging due to their locations being far from the buildings to be protected - Filter may not be compatible with the existing ground conditions - Pile test and D-wall test

-Long term settlements - Scheduling of work planning

-Unforeseen ground conditions -Excavation works causing unforeseen settlements -Groundwater drawdown

-Proximity of schools has special implications, -Victoria school is boarding school) - Scheduling of work planning

Excessive settlement - Insufficient ground information available for (Victoria School bridge and design canal structures)

Failing of loose material/ equipment/ rebar cages

Crane topple / Hoisted load - Poor crane footage hit crane - Incompetent lifting team - Poor lift plan - Congested work environment

Failure of lifting mechanism

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

- Damage to utilities - Damage to property

- Disruption to the site activities during installation of recharge well - Blockage of the filter gravel - Excessive water flow rate provided by the pumping system but little recharging effect

- Claims - Damage to buildings/structures - Complains from the public - Injuring the public

- Damage to buildings/structures - Delays - Claims - Closure of roads - Injuries / fatalities of construction workers and public

-Noise disruption to schools -Pick up and drop off times Damaged - Complains from the public - Injuring the public

- Serviceability issue with the bridge

IV

IV

V

V

III

IV

IV

III

III

I

I

IV

III

I

I

IV

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

I

S

IV

F

7

C

C

C

C

C

C

B

B

B

Ri

Initial Risk Category Ri

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

Impact

Package 1

-Activation criteria and minimum have been designed and indicated (Zone 1 to 3)

- Contractor's consultant has designed the recharging system, modified the configuration - Design of filter gravel has been provided

- Instrumentation / Monitoring - Reduce work inteface with public during peak hours

- Contractor’s Method Statements - instrumentation / monitoring - Real time monitoring - Specification of instrumentation and monitoring requirements by AE consultant - Strengthening and temporary propping when necessary - Additional site investigation

- Contingency planning, inspection and monitoring - Method Statements - Additional site supervision (e.g. traffic marshal) - Reduce work inteface with public during peak hours

- Provision of additional boreholes for bridge and canal design

- Approved PTW (e.g lifting) daily before commencement of work - Lifting Supervisor to ensure correct method of usage - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Avoid loading and unloading near edge of properties or access walkways - Low speed in lifting and lowering of material '- Signaller to communicate with crane operator during lifting and lowering operation - Lifting points to be marked, identified and approved - Approved Lifting plan - Material shall be stacked safely and within stacking limit and load

- Design and COS crane access - No Overloading at all times - Proper maintenance of crane - Only competent lifting team is allowed - Implemet Permit to lift - Include both Max. and Min load radius - Do not conduct lifting in congested work environment. - Provide exclusion zone and Provide warning signs. - Provide sufficient tag lines

- Apply PTW (e.g. lifting) daily before commencement of work - Monthly inspection of lifting mechanisms - Lifting Supervisor to ensure correct method of usage - Colour coding all lifting mechanisms for validity and serviceability levels - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Lifting points to be marked, identified and approved - Approved Lifting Plan

Mitigation Measures

8

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

IV

IV

V

V

III

IV

III

III

I

I

IV

III

I

I

V

V

I

S

V

F

C

C

C

C

C

C

C

C

C

Ri

Residual Risk Category Rr

11

- Provide proper recharging system - Provide proper filter gravel - Instrumentation/ Monitoring of settlement - Additional Site investigation

- Emergency Response planning - Provide proper recharging system - Provide proper filter gravel - Instrumentation/ Monitoring of settlement - Additional Site investigation - Control of bentonite pressures

- Perform ground improvements when necessary

-Emergency Response planning including Contingency planning -Instrumentation/monitoring to monitor strut loads. - Instrumentation/ real time monitoring - Sufficient vibration monitors with appropriate trigger levels to be installed. - Provision of recharge wells. -Provide proper recharging system -Provide proper filter gravel

12

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

*Action Owner

JHZH-PM

Risk Owner

JHZH-PM - Proper planning and traffic control - Provide soundproof wall - Close communication with the school and be cognisant of critical times in the school calendar

- Emergency Response planning - Insturmentation and monitoring of settlement - Additional Site investigation when necessary

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

May-20

Oct-17

Oct-17

Oct-17

Due Date By

Revision J 13 14

79 months

79 months

79 months

79 months

79 months

45 months

13 months

13 months

13 months

Risk Exposure Period

C

C

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Open

Open

Status

Date: 11/08/2017 15 16 17 Remarks

105

105

T309/ CNSS

T309 / CNSS

005

004

NA

N.A

Traffic Diversion for Option 1C (Laguna Park)

Traffic Diversion around Victoria School

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

5

'- Lack of communication between LTA, main contractors, and sub contractors.

Motorist confusion

Noise

Complaints from stakeholder

Traffic jam / congestion

'- Lack of coordination between JHZHJV and subbies operation team

- Poor planning

-Public confusion

Workers hit by traffic

- Congested road leading to Victoria school - Construction activities in front of Victoria school - Heavy machinery stationed along Siglap Link - Heavy traffic from new egress to Marine Parade Road - Pedestrians jaywalking -Inadequate signage and poor traffic control measures -Unsafe traffic layout -Failure to carryout trial trench for UG services -Failure to barricade work area and provide banksman to guide vehicular movement on site -Failure to equip with proper PPE

Hazard Cause

Risk associated with Traffic Diversion -Unsafe traffic conditions, accident hot spot and vehicles crashing into site -Damaged to UG services -Noise and dust pollution

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

- Collision of construction and public vehicles - Fatality - Delays - Claims - Injury to public or construction personnel - Tarbish reputation

- Collision of construction and public vehicles - Delays - Claims - Injury to public or construction personnel

Impact

Package 1

II

II

IV

S

F IV

C

C

Ri

Initial Risk Category Ri

7

-Clear and advance notification to all stake holders - Sufficient and clear notification signage to motorist – e.g. VMS - Coordinate closely with relevant authority e.g. LTA - Organise “work session” to brief all relevant parties - Briefing session to be conducted with all relevant parties on personnel on process of diversion. - Apply for lane closure - Close lane in accordance with COP Traffic control - Put up sufficient advance warning signage - Brief TCP to all relevant person prior work start - Carry out traffic diversion off peak hours. - Inform NEA about late traffic diversion work Potential noise issue - Ensure workers put on reflective vest. - Traffic controllers to equipped with light batons

- Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan '- Guard rail or rigid barrier to be setup and interlocked properly - designated path for access by pedestrians '- Code of Practise of Traffic Control and Work Zone -Approval of temporary traffic diversion layout by TM -Traffic layout and signage to follow TCP -Submit PSR (road) for clearance -Ensure good visibility of signage --Apply permit to dig prior to start work -Conduct RA/ SWP briefing

Mitigation Measures

8

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

II

II

V

S

F IV

C

C

Ri

Residual Risk Category Rr

11 Risk Owner

- Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan '- Guard rail or rigid barrier to be setup and interlocked properly - designated path for access by pedestrians '- Code of Practise of Traffic Control and Work Zone -Approval of temporary traffic diversion layout by TM -Traffic layout and signage to follow TCP -Submit PSR (road) for clearance -Ensure good visibility of signage --Apply permit to dig prior to start work -Conduct RA/ SWP briefing

JHZH-PM

JHZH-PM - To provide traffic marshals to direct traffic when necessary - To study provision of temporary traffic lights to faciltate passing of construction and public vehicles smoothly when necessary - Placement of cone or barrier during diversion without reduction in lane width -Desk top study of all utilities and carryout appropriate trial trench -Barricade work area and provide proper signage and warning to motorist and pedestrian. -Lane closure to avoid peak hours, applicable hours is 9:30-16:30 for daytime and 16:30-09:30 for night time closure -Flow chart indicating the flow of instruction enabling the lorry truck to enter the lane closure work area during soil removal or delivery of materials.

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10 12

JHZH-PM

JHZH-PM

*Action Owner

Jun-23

Mar-23

Due Date By

Revision J 13 14

79 months

79 months

Risk Exposure Period

C

C

Target Risk Rating

Open

Open

Status

Date: 11/08/2017 15 16 17

To be discuss further in briefing session later.

Further improvemen ts will be discuss in PSR roadworks

Remarks

005

Future developments or Addition & Alteration works 112 001 T309/CNSS T309/CDSS/112/001

110

T309/CDSS/110/005

N.A

T309/CNSS

109

Existing Conditions T309/CNSS

004

T309/CDSS/106/003

T309/CDSS/110/004

106

T309/CNSS

003

T309/CDSS/106/002

Interface with Adjacent Contracts T309/CNSS 110 004

106

T309/CNSS

002

T309/CDSS/106/001

T309/CDSS/109/006

106

T309/CNSS

001

006

106

Existing Utilities T309/CNSS

Future developments or Addition & Alteration works

Excavation

Excavation

Excavation for Utility Diversion Works

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

Clashes between railway structures and future underground infrastructure works and/or future above ground developments

Interfacing with adjacent contracts

Incompatible Interfacing with adjacent contracts

Seawall obstruction

Limited Work Areas

Damage to utilities

Damage to utilities and disruption to services

Damage to submarine cable

Hazard

4

5 Hazard Cause

- Injury or fatalities of public and construction workers Unplanned excavation -Insufficient marking on site -Failure to conduct detection test

- Damage to the equipment used - Deep foundation and diaphragm wall are not constructed properly

- Unforeseen higher than designed surcharge

- Damage to utilities - Damage to road surfaces - Damage to property

-Proposals for future underground infrastructure - Incompatible construction techniques and developments in direct conflict with alignment and stations - Delay of works - Unaware of future infrastructure and developments proposals

Effect of T310 TBM tunnels on D-Walls subway - Excessive ground movement near Entrance C - Movement to adjacent structures

Unappropriate or non-workable connection - Excessive ground movement design at interface of bored tunnels and station - Movement to adjacent structures end walls - Groundwater drawdown - Waterproofing problem and associated repairs

Abandon seawall

- Work areas too restricted or efficient workings - Schedule delays - Work areas require significant temporary - Unsafe environment for construction personnel works for their establishment traffic congestion

-Diversion and support of utilities across excavation: - Water pipe - Power Grid cables - SP Telecom cables - Starhub cables

6 Impact

Disturbance to public

-Non coordinated inter-contract utility diversion, - Delay - Remote disruption -Unforeseen obstructions - Missing information from utilities agencies - Insufficient trial trenches

Insufficient information about cable location

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Package 1

V

V

V

V

IV

II

II

I

I

IV

III

I

V

III

III

I

S

III

V

F

C

C

C

C

D

C

C

C

C

Ri

Initial Risk Category Ri

7

- PE to ensure surcharge level to within acceptable loading

- Contractor to review Development Interface Report in detail - Coordination meetings between interfacing designers - Coordination between all parties (Client, Contractor, designers)

- Coordination meetings between interfacing contractors and designers to be managed by Contractors - Construction Interface report by Contractor - Coordination between all parties (Client, Contractor, Designers)

- Coordination meetings between interfacing contractors - Construction Interface report by Contractor - Coordination between all parties (Client, Contractor, Designers) - Specifying waterproofing details @ interface

- Additional trial trench and site investigation

- Buidling temporary decking for efficient road/land use - Detailed SHE procedure to enforce safety

- Ongoing co-ordination with relevant utility companies - Contractor's Method Statement - Approved NCE - Pre-qualify Contractors - Apply PTW daily before commencement of work -Thorough study of utilities drawings -Cable detections by qualified LCDW -Provide clear utilities marking on site -Provide A3 size drawing of utility plan -Apply permit to dig -Barricade work area while trenching -Contact relevant utility agency for any presence of unidentified utility -Always treat utility as `live’ if encountered -Only manual digging allowed for trial trench -Full time supervision during trial trench -No mechanical excavation within 3 meters from live utilities. - Only manual excavation allowed for trial trench digging. - Brief utilities plan in language understood by the workmen.

- Method Statements - Additional site investigation - Approved NCE

- To divert submarine cable away from the station box

Mitigation Measures

8

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

V

V

V

V

IV

II

II

I

I

IV

III

I

V

IV

III

I

S

IV

V

F

C

C

C

C

D

C

C

C

C

Ri

Residual Risk Category Rr

11

12

- No stockpiling

- Close coordination with related parties

- Instrumentation and monitoring - Close coordination

- Emergency Response planning e.g. grouting - Methods Statement - Close coordination

- Cross check at site - Laise with related authority about the information of seawall

- Efficient site utilization plan for each different working stage - Hire a professional road safety review learn and checking when necessary

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

-Utility cable detection and trial trench should be JHZH-PM carried out to identify the alignment -Diversion out of the structure footprint -Emergency Response planning including Contingency planning -Close communication with utilities agencies -Cable detection -Properly mark the location of utilities and briefing site staffs, workers and sub-contractors -If unclear with the finding of services after reaching the 2m limit, conduct further detection to determine the presence of any services below. -Dimensions and depth of Trial Trenches recorded by Project Survey Team for As Build information Photo records of trial trench including any utility discovered are recorded

JHZH-PM

JHZH-PM

-Design protective measures and temporary support scheme for utilities across excavation -Close communication with inter-contract and utilities agencies -Identify clear markers for utilities locations lines and brief staffs, workers and subcontractors -Cable detection -Emergency Response planning including Contingency planning

JHZH-PM

*Action Owner

JHZH-PM

Risk Owner

- Divert submarine cable away from the station JHZH-PM box and identify the clearly marker

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10

May-20

May-20

May-20

May-20

Jan-17

Oct-17

Oct-17

Oct-17

Oct-17

Due Date By

Revision J 13 14

45 months

45 months

45 months

45 months

5 months

13 months

13 months

13 months

13 months

Risk Exposure Period

C

C

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Open

Open

Status

Date: 11/08/2017 15 16 17 Remarks

Construction Methodology T309/CNSS 117

009

T309/CDSS/117/009

Lifting with crane

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

●Crane collapse or failure ●Toppling of crane ●Crane hit surrounding structures, eg silo ●Hoisted material hit crane

Hazard

4

5 Hazard Cause

-Overloading of lifting equipment -Failure to observe safe work procedures -- Instability of working platform. - Failure of loose material equipment/ rebar cages - Lack of communication - Inadequate supervision and control - Unplanned and poor control of crane movement - Substandard lift plan

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

-Injury to site staff -Delay to construction -Damage to property

Impact

Package 1

IV

F II

S C

Ri

Initial Risk Category Ri

7

- Provide support plates for firm support - Apply PTW (e.g. lifting) daily before commencement of work - Full extension of outrigger prior to lifting - Approved Lifting Permit - No workers shall be allowed to stand below suspended loads - Lifting Supervisor to ensure correct method of usage - Approved lifting plan (e.g. full extension of outrigger, approved and proper use of slings) - Lifting points to be marked, identified and approved -Safety zone established -Tag line with coloured flag to be installed along hoarding to warn operator from crossing the line when turning during lifting -Tag line with coloured flag to be installed at the top of bentonite tank to warn crane operator and signal man to guide operator during crane movement. -Bentonite tanks near to Dwall will only be erected after the completion of Dwall. -To include min load radius in lift plan.

Mitigation Measures

8

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

V

F II

S C

Ri

Residual Risk Category Rr

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Reminder in tool box meeting - Lifting zone to be barricaded before works commence -Provide adequate hardstanding /firm working platform -Put in place the lifting permit system and display the relevant details on site. -Ensure no overloading of crane -Signaler to communicate with crane operator -Lift load by 300mm, hold for 3 seconds, all personnel 3m away -Approved lifting plan, reviewed by LE and approved by PM -Lifting operation supervised by lifting supervisor -Banksmen to guide crawler crane movement, ensuring no tracking over drain, trench or uneven ground. -Lifting points to be identified and approved -Low speed in lifting and lowering -Material shall be stacked safely and within stacking limit and load -Authorization of all machineries movement from point to point -Establish a permit to move system for heavy machineries -A lockout /tagout system during maintenance and breakdown period of mchineries -Maincon to control all machineries movement on site with daily discussion during coordination meeting -Setting up a security management plan that involved site security to be aware of the delivery of materials and ensuring no material delivery during lunch time and peak hour

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10 11

JHZH-PM

Risk Owner

12

JHZH-PM

*Action Owner

May-20

Due Date By

Revision J 13 14

45 months

Risk Exposure Period

C

Target Risk Rating

Open

Status

Date: 11/08/2017 15 16 17 Remarks

121

Fire and Explosions T309/CNSS

001

002

118

T309/CNSS

9

001

118

Ground Improvements T309/CNSS 118

T309/CNSS

T309/CDSS/121/001

T309/CDSS/118/002

T309/CDSS/118/001

T309/CDSS/117/010

Construction works involving flammable or explosive materials

Construction works for ERSS or permanent walls

Jet grouting

"L" shape D- wall cage installation - Tandam Lift

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

5

Inappropriate jet grouting methods

-Overloading of lifting equipment -Failure to observe safe work procedures -- Instability of working platform. - Failure of loose material equipment/ rebar cages - Lack of communication - Inadequate supervision and control - Unplanned and poor control of crane movement - Substandard lift plan

Hazard Cause

Fire or explosion during construction

-Encounter flammable materials - Breakage of buried services - Ignition of methane from peat layers - Contaminant gas - War relics/unexploded ordnances - Heavy vehicles carrying flammable materials may be driven into the construction site

Excessive deflection of Insufficient ground improvement / treatment ERSS or permanent walls works

Ground improvement failure

●Collision of cranes ●Crane collapse or failure ●Toppling of crane ●Crane hit surrounding structures, eg silo ●Hoisted material hit crane ●D wall stich snap ●Hoisted material hit crane

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

- Injury or fatality of public or construction workers - Damage to existing structures and services

- Flooding of excavation - Collapse of temporary works and adjacent structures - Injury of public or construction personnel - Disruption of essential services - Delays - Claims

- Collapse of ground - Injury or fatality of construction workers and public - Waterproofing problems and associated repair - Damage to buildings - Delay of works - Movements of adjacent structures

-Injury to site staff -Delay to construction -Damage to property

Impact

Package 1

F

V

V

V

IV

I

II

II

II

S

C

C

C

C

Ri

Initial Risk Category Ri

7

- Provision of appropriate plant - additional site investigation and geophysics when necessary - Gather knowledge from people with relevant experience - Apply PTW (e.g hot works) daily before commencement of work - Safety Datasheet and Warning signs and Emergency contacts on display - Reporting to Safety and Security Department

- Contractor to produce robust Design - Method Statements to ensure safe working methods - Robust ERSS Design - instrumentation / monitoring e.g. LBs to monitor building movement, LGs for ground movement and IW or XYZ for ERSS.

- Contractor to produce robust design - Jet grouting trials - Specifying waterproofing details @ interface - Instrumentation / Monitoring e.g. LBs to monitor building movement, LGs for ground movement and IW or XYZ for ERSS. - Additional site investigation and geophysics

- Provide support plates for firm support - Apply PTW (e.g. lifting) daily before commencement of work - Full extension of outrigger prior to lifting - Approved Lifting Permit - No workers shall be allowed to stand below suspended loads - Lifting Supervisor to ensure correct method of usage - Approved lifting plan (e.g. full extension of outrigger, approved and proper use of slings) - Lifting points to be marked, identified and approved -Safety zone established -Tag line with coloured flag to be installed along hoarding to warn operator from crossing the line when turning during lifting -Tag line with coloured flag to be installed at the top of bentonite tank to warn crane operator and signal man to guide operator during crane movement. -Bentonite tanks near to Dwall will only be erected after the completion of Dwall. -To include min load radius in lift plan.

Mitigation Measures

8

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

V

V

V

V

F

I

II

C

C

C

C

II

II

Ri

S

Residual Risk Category Rr

11

JHZH-PM

Risk Owner

- Proper and independent flammable materials storage and management - Emergency Response Planning including Contingency planning e.g. quick evacuation route - Permit to carry hazardous material

- Provide efficient geometric design and the road level to mitigate flooding - Witness the instrumentation reading - Regular review and analyse instrumentation reading - Emergency Response planning include Contingency planning, inspection and monitoring

JHZH-PM

JHZH-PM

- High quality construction records and material JHZH-PM testing - Methods statement - Pre-qualify contractors - Regular review instrumentation reading of inclinometers and ground settlement markers in trial test and feedback main works - Emergency Response Planning including Contingency planning e.g. stop all excavation, ensure safe escape route for workers, additional temporary struts.

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Reminder in tool box meeting - Lifting zone to be barricaded before works commence -Provide adequate hardstanding /firm working platform -Put in place the lifting permit system and display the relevant details on site. -Ensure no overloading of crane -Signaler to communicate with crane operator -Lift load by 300mm, hold for 3 seconds, all personnel 3m away -Approved lifting plan, reviewed by LE and approved by PM -Lifting operation supervised by lifting supervisor -Banksmen to guide crawler crane movement, ensuring no tracking over drain, trench or uneven ground. -Lifting points to be identified and approved -Low speed in lifting and lowering -Material shall be stacked safely and within stacking limit and load -Authorization of all machineries movement from point to point -Establish a permit to move system for heavy machineries -A lockout /tagout system during maintenance and breakdown period of mchineries -Maincon to control all machineries movement on site with daily discussion during coordination meeting -Setting up a security management plan that involved site security to be aware of the delivery of materials and ensuring no material delivery during lunch time and peak hour

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10 12

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

*Action Owner

Mar-23

Jan-18

Jul-17

May-20

Due Date By

Revision J 13 14

79 months

16 months

10 months

45 months

Risk Exposure Period

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Status

Date: 11/08/2017 15 16 17 Remarks

122

994

994

Flooding T309/CNSS

Site set up T309/CNSS

T309/CNSS

002

001

002

NA

NA

T309/CDSS/122/001

4

5 Hazard Cause

MEWP topple

Hit by fallen object

Fall from height

Noise Barrier structural failure

6

- Collapse of temporary works - Excessive movement / Collapse of adjacent structures - Injury or fatalities of public and construction workers

-Interrupted construction, -Delays, -Environmental pollution

Impact

-Damage to own and public properties (Claims) - Injury or fatalities of public and construction workers

Old machinery and poor maintenance causing disturbance to nearby resident

Installation of sheet piles Noise pollution (foundation support for sound barrier)

Installation of sheet piles Accidental dislodgement of -Carelessness and inexperience operator. (foundation support for sheet pile during driving - Faulty vibro hammer sound barrier)

Structure failure of machinery

Installation of sheet Using of poor condition piles (foundation support for machinery sound barrier)

-Serious injury to worker and property. -Stop work causing delay

-Disturbance to neighbouring resident -Hearing injury to workers

-Low productivity Job delay and behind schedule -Cost implication

-Serious injury to worker and property. -Stop work causing delay

Installation of sheet piles Poor ground condition (foundation support for sound barrier)

-Toppling of machinery resulting in damage to property. -Injury to surrounding people.

-Serious injury to worker and property. -Stop work causing delay -Damage to machineries

Installation of sheet Collision of machinery and piles Constraint of work area (foundation support for site people. sound barrier)

-Damage to underground services -Disruption to stakeholders Location of utilities not reflected in utility drawing -Penalty charges by authority -Stop work order by authority -Delay to work schedule

-Failure to provide fall protection provision - Failure to provide control - Poor footage - Over loading of MEWP

-

- Collapse of temporary works - Incorrect information on adjacent structures - Not identifying the behaviour and response of - Damage to own and public properties (Claims) - Injury or fatalities of public and construction the ground and adjacent structures workers

-Flawed design of temporary works - Inappropriate use / misinterpretation of design codes - Lack of understanding of design software and output - Temporary works design is incompatible with adjacent structures

Flooding from the Opera -Damage the canal or foundation during Estate Canal at Siglap Link construction, -Extreme flooding event; -Tidal fluctuation -Structural problem of the canal

Hazard

Installation of sheet piles Damage to utilities (foundation support for sound barrier)

Setting up of Noise Barriers

Construction works near Opera East Canal

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Package 1

IV

IV

IV

IV

IV

IV

I

II

II

I

I

II

II

II

IV

IV

II

I

S

IV

V

F

B

C

C

B

B

C

C

C

C

C

Ri

Initial Risk Category Ri

7

V

V

-Additional sling tied to sheetpile and machinery as extra protection in case grabber gives way -Ensure sheetpile is clamped tightly between the grabber jaws before hoisting up vertically for installation

V

V

V

V

I

II

II

I

I

II

II

II

V

V

II

I

S

V

V

F

C

C

C

C

C

C

C

C

C

C

Ri

Residual Risk Category Rr

11 Risk Owner

12

Daily pre operation check on grabber by operator before start of work

Regular maintenance regime in place

LOTO system applied during maintenance period

-Ground preparation completed with the issuance of COS from PE -Ensure no overloading of machinery (Load kept at 75% of SWL

Apply for permit to move for machinery movement from point to point

Cable detection by LEW

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

- Strengthening of noise barrier when necessary JHZH-PM - Additional site investigations and localized ground improvement when necessary - Emergency Response planning including Contingency planning e.g. stop all excavation, ensure safe escape route for workers, additional temporary struts. - Approved Method Statement

-Enveloped MEWP work platform with scaffold JHZH-PM netting to contain material. Limit max. 2 person on MEWP. Max. weight 120kg. Firm and compacted ground for MEWP access. Provide adequate exclusion zone and signage. Provide banksman to ensure no authorised entry in to work zone.

JHZH-PM

JHZH-PM

*Action Owner

JHZH-PM - Engage experienced and competent consultant to perform the design - Engage experienced and competent contractor - Emergency Response planning including Contingency planning e.g. stop all excavation, ensure safe escape route for workers, additional temporary struts. - Approved Method Statement

JHZH-PM - Provide efficient geometric design and the road level to mitigate flooding -Awareness of climatic conditions -Regular monitor of water level in Opera estate Canal -Emergency Response planning including Contingency planning

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10

-Installed sound barrier. -Used of silent piler. -Refrain from working at night and weekend/PH

-Machine to be inspected and certified by AE. -Regular monthly maintenance of machineries

-Access to be laid with hardcore and compacted. -Steelplate to be laid on top of hardcore. -Movement of machinery must be guided by benchemen

-Work zone to be barricaded to prevent unauthorized entry -Used of tag line to control swaying of load - Employed skilled operator and experienced lifting team

-Carry out cable detection and trial trench along the path of sheet piles. -Apply permit to dig prior to work start.

- Provision of Fall Protection Plan. - Establish PTW-Height system. - Provide proper access. - Provide adequate work platform. - Licensed MEWP operator. - Familiarisation briefing prior appointment.

- Perform further structural or geotechnical investigations e.g. coring, trial trenching - Apply PTW (e.g. welding) daily before commencement of work - Certified welder

- Sensitivity of design input parameters - Pre-qualify contractor - Apply PTW (e.g. welding) daily before commencement of work - Certified welder

- Method Statements - Additional site investigation -Confirmation with LTA on any specific flood protection measures required during construction

Mitigation Measures

8

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

Due Date By

Revision J 13 14

79 months

79 months

79 months

79 months

79 months

79 months

79 months

79 months

79 months

79 months

Risk Exposure Period

C

C

C

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Open

Open

Open

Status

Date: 11/08/2017 15 16 17 Remarks

994

996

996

997

T309/CNSS

Vector Management T309/CNSS

T309/CNSS

Mobilization T309/CNSS

001

002

001

003

NA

NA

NA

NA

Traffic Diversion

Workers working on site

Setting up of Hoarding

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

5 Hazard Cause

Risk associated with Traffic Diversion -Unsafe traffic conditions, accident hot spot and vehicles crashing into site -Damaged to UG services -Noise and dust pollution

Transmission of Dengue and Zika

Mosquito bites on construction/ public personnel

6

- Collapse of temporary works - Excessive movement / Collapse of adjacent structures - Injury or fatalities of public and construction workers

Impact

- Transfer (delivery and lifting) material, plant and manpower -Inadequate signage and poor traffic control measures -Unsafe traffic layout -Failure to carryout trial trench for UG services -Failure to barricade work area and provide banksman to guide vehicular movement on site -Failure to equip with proper PPE

- Mosquito breeding - Mosquito bites

- Mosquito breeding - Mosquito bites

- Traffic jam - Injury to public or construction personnel - Claims - Delays

- Injury or fatality of public or construction personnel - Claims - Delays

- Injury to public or construction personnel - Claims - Delays

- Collapse of temporary works - Incorrect information on adjacent structures - Not identifying the behaviour and response of - Damage to own and public properties (Claims) the ground and adjacent structures

Hoarding structural failure -Flawed design of temporary works - Inappropriate use / misinterpretation of design codes - Lack of understanding of design software and output - Temporary works design is incompatible with adjacent structures

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Package 1

F

IV

IV

IV

IV

IV

II

I

I

II

II

S

C

B

B

C

C

Ri

Initial Risk Category Ri

7

- Code of Practise of Traffic Control and Work Zone - Use of barrier and/or gate guards for exit/entrances to site -Approval of temporary traffic diversion layout by TM -Traffic layout and signage to follow TCP -Submit PSR (road) for clearance -Ensure good visibility of signage --Apply permit to dig prior to start work -Conduct RA/ SWP briefing -Desk top study of all utilities and carryout appropriate trial trench -Barricade work area and provide proper signage and warning to motorist and pedestrian. -Lane closure to avoid peak hours, applicable hours is 9:30-16:30 for daytime and 16:30-09:30 for night time closure

- Pest control '- Emergency Response planning - Vector control management - Additional supervision - Oiling in stagnant water and other respective areas - Provision of insect repellents to site staff

- Pest control - Emergency Response planning - Vector control Management - Additional supervision - Oiling in stagnant water and other respective areas - Provision of insect repellents to site staff

- Perform further structural or geotechnical investigations e.g. coring, trial trenching

- Sensitivity of design input parameters - Engage experienced and competent consultant to do the design - Engage experienced and competent contractor - Pre-qualify contractor

Mitigation Measures

8

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

IV

V

V

V

V

F

II

I

I

II

II

S

C

C

C

C

C

Ri

Residual Risk Category Rr

11 Risk Owner

JHZH-PM

JHZH-PM

JHZH-PM - Properly traffic control and signages with qualified traffic marshal - Clearly defined zones for accessible pathways and restricted areas - Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan - Emergency Response planning including Contingency planning, inspection and monitoring - Lifting zone to be barricaded before works commence - Placement of cone or barrier during diversion without reduction in lane width -Flow chart indicating the flow of instruction enabling the lorry truck to enter the lane closure work area during soil removal or delivery of materials.

- Regular inspection of site to identify and eliminate breeding sites - Misting

- Regular inspection of site to identify and eliminate breeding sites - Misting

JHZH-PM - Strengthening of hoarding when necessary - Additional site investigations and localized ground improvement when necessary - Emergency Response planning including Contingency planning e.g. stop all excavation, ensure safe escape route for workers, additional temporary struts.

JHZH-PM - Engage experienced and competent consultant to perform the design - Engage experienced and competent contractor - Emergency Response planning including Contingency planning e.g. stop all excavation, ensure safe escape route for workers, additional temporary struts.

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10 12

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

*Action Owner

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

Due Date By

Revision J 13 14

79 months

79 months

79 months

79 months

79 months

Risk Exposure Period

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Status

Date: 11/08/2017 15 16 17 Remarks

997

999

Other Hazards T309/CNSS

997

T309/CNSS

T309/CNSS

001

3

002

T309/CDSS/999/001

N.A

NA

Construction Works near Residental area

Lifting with crane

Lifting with crane

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

5

- Breakage of lifting chain - Breakage of lifting sling - Failure of brake motor/gear - Failure of sling/chain buckles and hooks - Overloading of carried loads over limited of design capacity - Unauthorized modification of lifting points

Hazard Cause

Noise, dust and vibration

-Construction works in close proximity to the public -Excessive noise due to construction -Excessive noise due to bored and barette pile testing

Sharp edge material being - Site personnel cut by sharp material during lifted/ lowered/ handled handling

- Improper securing of material/ equipment Failing of loose material/ equipment including heavy - Overloading of material/ equipment - Slight tilt in crane mchineries / equipment '- Sudden movement of crane boom - Early release of jack base / hydraulic jack out riggers

Crane topple / Hoisted load - Poor crane footage hit crane - Incompetent lifting team - Poor lift plan - Congested work environment

Failure of lifting mechanism

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

- Injury to public or construction personnel - Disruption of essential services - Negative PR - Delays - Claims

- Injury and fatality to construction personnel - Delays - Claims

III

II

IV

IV

I

IV

I

IV

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

I

S

IV

F

7

C

C

B

B

B

Ri

Initial Risk Category Ri

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

Impact

Package 1

- Contingency planning, e.g. additional noise barriers, inspection and monitoring - Method Statements to ensure safe working methods - Installation of noise barriers - Noise level monitoring - Engaging community for feedback '- Noise, dust control plan

- Store all sharp material into material cages when possible - Pack/ organize sharp material - Use of PPE (e.g appropriate safety gloves, long sleeves, helmet and safety boots and glasses)

- Approved PTW (e.g lifting) daily before commencement of work - Lifting Supervisor to ensure correct method of usage - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Avoid loading and unloading near edge of properties or access walkways - Low speed in lifting and lowering of material '- Signaller to communicate with crane operator during lifting and lowering operation - Lifting points to be marked, identified and approved - Approved Lifting plan - Material shall be stacked safely and within stacking limit and load - Always secure materilas/heavy machineries on lorry bed before release out riggers / hydraulic jack. - Do not stay in libne of fire at all times.

- Design and COS crane access - No Overloading at all times - Proper mainyenance of crane - Only competent lifting team is allowed - Implemet Permit to lift - Include both Max. and Min load radius - Do not conduct lifting in congested work environment. - Provide exclusion zone and Provide warning signs. - Provide sufficient tag lines

- Apply PTW (e.g. lifting) daily before commencement of work - Monthly inspection of lifting mechanisms - Lifting Supervisor to ensure correct method of usage - Colour coding all lifting mechanisms for validity and serviceability levels - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Lifting points to be identified and approved - Approved Lifting Plan

Mitigation Measures

8

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

III

II

IV

V

I

I

V

V

I

S

V

F

D

C

C

C

C

Ri

Residual Risk Category Rr

11

12

- Vibration control plan - Vibration monitoring

JHZH-PM

JHZH-PM

JHZH-PM

- '- Identify sharp material and dipose (e.g. nails, JHZH-PM broken glasses) - Wrap sharp edges when possible

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

*Action Owner

JHZH-PM

Risk Owner

JHZH-PM

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10

Mar-23

Oct-17

Mar-23

Oct-17

Mar-23

Due Date By

Revision J 13 14

79 months

13 months

79 months

13 months

79 months

Risk Exposure Period

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Status

Date: 11/08/2017 15 16 17 Remarks

999

999

999

999

999

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

006

005

004

003

002

T309/CDSS/999/006

T309/CDSS/999/005

T309/CDSS/999/004

T309/CDSS/999/003

T309/CDSS/999/002

4

Damage to construction works

-Traffic congestion - Unauthorized entry of personnel to site

Road vehicles entering construction site / excavations

Hazard

5

Setting up of Noise Barrier

Traffic Diversion

-Occurrence of a natural disaster during construction - Flooding - Heavy rainfall causing significant ground water table rise

- Construction activities require frequent transport movements - Works at site with long working hours for 7 days a week

-Construction works in close proximity to the public and existing housing -Excessive noise due to construction

-Spoil removed to designated location remote Movement of heavy vehicles causing disruption from site to traffic movement

Noise Barrier and foundation

6 Impact

- Injury to public or construction personnel - Disruption of essential services - Negative PR - Delays - Claims

- Delay and accidents, - ECM issues, - Mosquito breeding, - Security problems

III

III

III

V

IV

IV

I

V

- Flooding of excavation - Collapse of temporary works and adjacent structures - Injury or fatality of public or construction personnel - Disruption of essential services - Delays - Claims

II

S

II

IV

F

7

D

C

D

C

C

C

Ri

Initial Risk Category Ri

IV

-Environmental pollution

Package 1

- Method Statements - additional site investigation - Provision of Noise barrier - Monitoring of Noise - Noise control plan - Engage community regularly and gather feedback

- Method Statements -Additional traffic management

- Method Statements - additional site supervision - ECM Plan

- Robust ERSS design including flood barriers when necessary - Temporary groundwater controls and pumps within excavation - Specifying water proofing details @ interface

- Design and approved traffic diversions - Minimise traffic around construction sites - Use of barrier and/or gate guards for exit/ entrances to site

- Design and approved traffic diversions - Clear and good signages - Minimise traffic around construction sites

Mitigation Measures

8

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

- Complaint from nearby occupants - Complaint from LTA - Working time may be reduced with delay to programme

-Traffic congestion due to minimum diversions, - Injury to public or construction personnel drivers seeking alternative routes - Damage to temporary or permanent works

Hazard Cause

Discharge into Canal from -Heavy rain construction - Insufficient control on site -Surface run off, construction materials Construction Works (bentonite, concrete, grout, near Drains and Canal maintenance/cleaning facilities)

Construction Works near Drains and Canal

Traffic Diversion

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

V

IV

III

III

IV

I

V

IV

II

II

S

V

V

F

D

C

D

C

C

C

Ri

Residual Risk Category Rr

11 Risk Owner

12

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM - To provide traffic marshals to direct traffic when necessary - To study provision of temporary traffic lights to faciltate passing of construction and public vehicles smoothly -Designated haul routes -Contingency planning, inspection and monitoring - Placement of cone or barrier during diversion without reduction in lane width - Minimize loud noise activity during evening and weekends - Monitor noise meters at designated intervals - Contingency planning, inspection and monitoring

JHZH-PM

JHZH-PM - Install additional EC measures (e.g. silt fences, nets) when necessary '- Regular inspection of site by ECO at affected zones - Contingency planning, inspection and monitoring

- Close communication with related authority - Emergency Response planning including Contingency planning e.g. quick evacuation route - Provide efficient geometric design and the road level to mitigate flooding

JHZH-PM

JHZH-PM

*Action Owner

JHZH-PM - To provide traffic marshals to direct traffic when necessary - Clearly defined zones for accessible pathways and restricted areas - Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan - Guard rail or rigid barrier to be setup and interlocked properly - Code of Practise of Traffic Control and Work Zone - Placement of cone or barrier during diversion without reduction in lane width

JHZH-PM - To provide traffic marshals to direct traffic when necessary - Clearly defined zones for accessible pathways and restricted areas - Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan - Guard rail or rigid barrier to be setup and interlocked properly - Code of Practise of Traffic Control and Work Zone - Placement of cone or barrier during diversion without reduction in lane width

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10

Mar-20

Mar-23

Mar-20

Mar-23

Mar-23

Mar-23

Due Date By

Revision J 13 14

45 months

79 months

45 months

79 months

79 months

79 months

Risk Exposure Period

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Status

Date: 11/08/2017 15 16 17 Remarks

999

999

999

999

999

999

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

013

012

011

010

009

008

007

N.A

N.A

N.A

N.A

N.A

N.A

N.A

Operation of machineries / equipment

Recahrge well work

Lifting with Excavator (Pick and Carry)

Traffic Diversion

Traffic Diversion

Removal of sludge

Cleaning

4

5

-Pipe leakage and burst -Loose connection

-Pipe leakage and burst -Loose connection -Lose control of hose

Hazard Cause

- Engine catch fire - Hydraulic oil leakage - Unvoluntary movement of machines boom / arm. - Load bearing componant give way.

Water pipe. Power grid cables. Telecom cables. High tension cables.

6

-Damage of machinery -Injury of worker -Damage of materials

-Damage of machinery -Injury of worker -Damage of materials

- Traffic jams hindering construction vehicles - Bottlenecks hindering traffic speed - Crossed traffic and pedestrian circulation paths - injury to public and/or construction work

- Traffic jams hindering construction vehicles - Bottlenecks hindering traffic speed - Crossed traffic and pedestrian circulation paths - injury to public and/or construction work

'- Injury to public or construction personnel - Contaminate soil, groundwater and surface water

- Injury to public or construction personnel

Impact

- Overloading or over running of machineries / -Damage of machinery -Injury of worker equipment result in over heating. -Damage of materials - Hydraulic leak - Poor maintenance reguime - Misue of machineries or equipment

-Unplanned Drilling. - Insufficient marking on site. - Failure to conduct detection test.

-Uneven ground - Unauthorised lifting - Improper rigging -Overloading -Inexperience operator

-“A’ frame topple - Injury to public - Fingers / hand caught in rotating parts

-Damaged to :

-Uneven ground - Unauthorised lifting - Improper rigging -Overloading -Inexperience operator

-Toppling of excavator - Falling of load/ material

Risk associated with Traffic - Change to road condition due to delivering Diversion material to site

Risk associated with Traffic - Change to road condition due to construction Diversion work, poor line of sight - Changed traffic condition causes confusion to road users - Improper/ unclear signages - Improper/ unclear separation of pedestrians paths and work site ingress/ egress points - Pedestrians jaywalking

Sludge spill

Use of high ultra water jet

Hazard

Note * - Action Owner will be reassigned from PM to Engineer-in-Charge when respective Engineer-in Charge is established

999

T309/CNSS

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Package 1

F

IV

IV

IV

IV

IV

IV

IV

II

II

II

II

II

II

II

S

B

B

B

B

C

C

C

Ri

Initial Risk Category Ri

7

- Ensure maintenance regisme is carried out properly. - Always equip machineries / equipment with valid fire extinguisher - Never misuse machineries / equipment. Use it as what it is intended for.

-Thorough study of utilities drawings. - Cable detections by qualified LCDW - Provide clear utilities marking on site - Provide A3 size drawing of utility plan - Apply permit to dig and implement “checklist for working near utility” - Barricade work area while trenching

- Ensure work assess is planned. - Ensure adequate access for work mobilisation and public access. - Only competent lifting crew is allowed to involved in mobilisation. - PTW-Lifting approved prior unloading. - Provide proper exclusion zone to segregate work and public. - Provide warning signs.

●The excavator designed for pick and carry operations must have load chart stating clearly the limitattions for picks and carry operation ●Tag line shall be used during operation ● Ensure the route of travel is firm and level ●Lifting supervisor to ensure the load is firmly secured and tied ●Benchman to guide excavator during the pick and carry operation

- Design stages of traffic diversion to allow construction to be carried out section by section - Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan - Safety barrier to be setup at designated storage zones - Proper signages display at prominent locations - Code of Practise of Traffic Control and Work Zone - designated path for access by pedestrians - Control unauthorized entry of personnel into loading/unloading zone during material delivery

- Design stages of traffic diversion to allow construction to be carried out section by section - Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan - Guard rail or rigid barrier to be setup and interlocked properly Proper signages display at prominent locations - Code of Practise of Traffic Control and Work Zone

- Competent staff - Provide safety warning signage to keep other works clear from work area - Provide safety access to treatment plant - Permit for handling of sludge - Provide emergency contact no.

- Assign two trained hydro jetting operators. - Rotate shift every alternate hours - Provide safety warning signage to keep other works clear from work area - Provide safety access to washing bay

Mitigation Measures

8

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

V

V

V

V

V

II

II

II

II

II

II

II

V

V

S

F

C

C

C

C

C

C

C

Ri

Residual Risk Category Rr

11

JHZH-PM

JHZH-PM

Risk Owner

JHZH-PM

JHZH-PM - Ensure fire extingisher is checked on a monthly basis - Monitor mechnais attendance for maintenance closely -

-Contact relevant utility agency for any presence JHZH-PM of unidentified utility Always treat utility as `live’ if encountered Only manual digging allowed for trial trench Full time supervision during trial trench

- Provide blinker lights to alert night motorist and /or pedestrian. - Ensure footage is firm and level at all times. - Never drag load. Lift vertically.

-AE to examine the lifting capacity of excavator JHZH-PM and issued the certification for the lifting. -Pick and carry operation is guided in SS536 : 2008

JHZH-PM - To provide traffic marshals to direct traffic when necessary - To study provision of temporary traffic lights to faciltate passing of construction and public vehicles smoothly - Placement of cone or barrier during diversion without reduction in lane width

JHZH-PM - To provide traffic marshals to direct traffic when necessary - To study provision of temporary traffic lights to faciltate passing of construction and public vehicles smoothly - designated path for access by pedestrians - Placement of cone or barrier during diversion without reduction in lane width

- Contain and handle spillage (e.g. excavate spill site and treat with dry sand, temporary diking) immediately - Contact additional emergency services when necessary

- Assign safety supervisor when possible at work place to ensure operation is safe - Barricade work area to prevent unauthorized access and display warning signage.

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10 12

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

*Action Owner

May-23

May-23

May-23

Mar-23

Mar-23

Mar-23

May-20

Mar-23

Due Date By

Revision J 13 14

79 months

79 months

79 months

79 months

79 months

79 months

45 months

79 months

Risk Exposure Period

C

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Open

Status

Date: 11/08/2017 15 16 17 Remarks

17th Aug 2017

3 Months Programme Look ahead Risk and Mitigation

Construction of Siglap Station Thomson‐East Coast Line

Contract T309

2) To identify the major risk hazards and elaborate the mitigation measures in this  workshop

1) To identify the major works activities for the next three months, Aug 2017 – Oct 2017

Objectives of this workshop:

Guide Wall & D‐Wall construction

Entrance C

Guide Wall & D‐Wall construction

3

Cooling Tower D‐Wall construction Recharge Well Installation Excavation RC Work

Noise Panel installation near to Laguna Park Hoarding Shifting Installation Guide Wall & D‐Wall construction

Guide Wall & D‐Wall construction Mob/demob of machineries

Entrance B

Entrance D

Entrance A

Upcoming Works Aug 17 – Oct 17

Mob / demob heavy machineries

Entrance A

1. ENT.A Mob / demobilisation Risk and measures

Mob / demo  heavy  machineries 

Activity

Workers hit by  topple  machineries

Machines topple

Hazard 

Poor  supervision

Poor planning

Hazard  Cause

Ensure proper footage for heavy machineries park/access Never mob/demob during wet weather condition

‐ ‐

Only relevant staff are allowed to be involved in mob/demob Risk assessment must be approved prior activity Never mob/demob at congested work area Always ensure height limit is <4.5m Operator deployed must be appointed and licensed (if applicable) Machines must be approved by LTA prior mobilisation New machines to comply with LTA “Approval Procedure for new  machine”.

‐ ‐ ‐ ‐ ‐ ‐ ‐

Provide exclusion zone and banksman

Angle of ramp within machine manufacturer recommendation

‐

‐

Ramp of trailer must be equal or wider than machine crawler belt. 

‐

trailers are used for mob / demob

JV LE (Killi) Sub con supervisor

‐ ‐

JV LE (Killi) JV super. (Peter) JV super. (Peter) Sub con supervisor Sub con supervisor JV LE (Killi) JV LE (Killi)

‐ ‐ ‐ ‐ ‐ ‐ ‐

Sub con supervisor

JV LE (Killi)

‐

‐

JV LE (Killi)

‐

JV LE (Killi)

‐

‐

Obtained machineries technical information to ensure fit for purpose 

Action Owner

Mitigation Measure

1. ENT.A Mob / demobilisation Risk and measures

New machines – Seek LTA approval by submission of  relevant document and requirement prior mobilisation.

1. ENT.A Mob / demobilisation Risk and measures

Never mob/demob at congested work area

Avoid mob/demob on night shift

Mob/demob on clear and dry weather condition

Ground preparation to ensure stable footage for mobilisation

1. ENT.A Mob / demobilisation Risk and measures

• Turning radius of trailers etc

• Length and height of trailers

• Capacity of trailers

trailers <4.5m.

• Total height of loaded machines on 

• Weight of machine

• Width of machine

• Width of machine track

FOS)

• Max angle of machines travel (giving 

Obtain technical information of  machineries such as;

1. ENT.A Mob / demobilisation Risk and measures

conditions etc.

• Machineries in good working 

submitted and accepted.

• All required documentation 

• Approval of machines by LTA / JV

accordance with design

• Area to park and steel plate layout 

machineries (giving FOS)

• Ground bearing for heavy 

Obtain other information such as;

Provide exclusion zone for mob‐demob activity

Conduct pre‐check prior mob/demob of machines

Alcohol check on operator  involved in mob/demob prior  operation

1. ENT.A Mob / demobilisation Risk and measures

Traffic controllers  to guide  mob/demob  in/out site  assisted by LE and  relevant staff

Traffic control in place to ensure  smooth transition into worksite

Only relevant personnel are allowed to  get involved in mob/demob operation

1. ENT.A Mob / demobilisation Risk and measures

Conduct briefing to relevant personnel involved in mob/demob activity

Guide Wall & D‐Wall construction Recharge Well Installation Excavation Work

Cooling Tower

Cooling Tower Works

Cooling Tower Works

Area of excavation

Excavation  work

Activity

Fall into  Excavation

Excavation  Collapse

Risk 

•

Incompetent  crew

Poor ground  condition

•

• •

• •

‐

KKL Supervisor

Gajan (JV Engineer) KKL Supervisor

KKL Supervisor KKL Supervisor KKL Supervisor

‐ ‐ ‐ ‐ ‐

KKL Supervisor KKL Supervisor

‐ ‐

Peter (JV Superintendent) Thomas (Senior Supervisor)

‐ ‐

• • Ensure work assess is planned. Ensure adequate access for work mobilisation  and public access. Only competent excavation crew is allowed to  involved. PTW‐Excavation approved prior activity. Provide proper exclusion zone to segregate  man and machines. Provide warning signs. Provide blinker lights to excavator and proper  lighting particularly for night work. Ensure footage is firm and level at all times. Provide proper design and COS for shoring or  sloping. No stock pipe of spoil at site. To cover with  canvas in case of 

Action Owner

Mitigation Measure

• Poor Shoring /  • Sloping

Poor Planning

Hazard  Cause

2. Excavation work (Cooling Tower) – Risk mitigation

Risk 

Instability of  ERSS/  temporary  Works

Activity

Excavation  work

Ensure correct grade, dimensions of steel  materials used in strutting system as per  details construction drawings. Good control on the welding quality – UT for  butt weld & MPT for fillet weld

•

•

Poor  workmanship

Only competent welders are allowed to weld

•

Sensitivity of design input parameters / robust  design to minimise movement

Sufficient review of instruments monitoring  results by Instrument Engineer and QPS

•

•

Independent Instrumentation Monitoring  Specialist

•

‐

‐

‐

‐

‐

‐

Ensure construction sequence is in accordance  ‐ with design

Jay Cel (JV Project Engineer)

Jay Cel (JV Project Engineer)

Jay Cel (JV Project Engineer)

Jay Cel (JV Project Engineer)

Desi (Senior Engineer)

Desi (Senior Engineer)

Peter (JV Superintendent)

Action Owner

•

Mitigation Measure

Insufficient  control of the  works

Design  implementati on incorrect Insufficient  monitoring

Hazard  Cause

2. Excavation work (Cooling Tower) – Risk mitigation

Excavation  work

Activity

Excessive wall  deflection and  ground  movement

Ground  instability  during  excavation

Risk 

Insufficient  control of the  works

Design  implementati on incorrect Insufficient  monitoring

Hazard  Cause

•

•

•

•

•

‐

‐

‐

‐

‐

Olive (JV Senior engineer)

Jay Cel (JV Project engineer)

Peter (JV Superintendent)

Olive (JV Senior engineer)

Olive (JV Senior engineer)

Olive (JV Senior engineer)

‐

• Recharge well to be installed before excavation  commences Monitor alert level and suspension level of  instruments Ensure all instrumentation are in place before  excavation commencement Excavation sequence in accordance with  design Independent monitoring of ERSS including  struts loads, and joint review of  instrumentation results by Instrumentation  Engineer & QP(S).  Monitor inclinometer (daily) and strut load  readings (real‐time)

Action Owner

Mitigation Measure

2. Excavation work (Cooling Tower) – Risk mitigation

2. Excavation work (Cooling Tower) – Risk mitigation

16

2. Excavation work (Cooling Tower) – Risk mitigation

17

Locations of strain gauge / Load Cell

Risk 

Noise – result  in complains

Activity

Excavation  work

Noise work  activities

Hazard  Cause

•

• • • •

‐

‐ ‐ ‐ ‐

Peter (JV Superintendent)

Peter (JV Superintendent) Manoj (JV ECO) Peter (JV Superintendent) Erin (JV SPRO)

Killi (JV Lifting Eningeer)

‐

• Equipment and machinery with noise  insulating material Setting up of noise barrier around work site Monitoring of site noise level  Adhere to designated work hours Keeping stakeholders informed on activities  and planning activities (e.g. school exam  period) Avoid noisy work after normal working hours.

Action Owner

Mitigation Measure

2. Excavation work (Cooling Tower) – Risk mitigation

Zone 1

Noise Barrier

Zone 2

Zone 3

Zone 4

Traffic Diversion TD1C

2. Excavation work (Cooling Tower) – Risk mitigation

Zone5

Zone6

19

Recharge  well work

Activity

Fingers / hand  caught in  rotating parts

Injury to public

“A’ frame  topple

Risk 

Incompetent  crew

Poor ground  condition

Poor footage

Poor  mobilization  planning

Hazard  Cause

3) Recharge Well work – Risk mitigation

• •

• •

• •

•

‐ ‐

‐ ‐

‐ ‐

‐

Killi (JV LE) Killi (JV LE)

Thomas (Senior Supervisor) Thomas (Senior Supervisor)

Killi (JV LE) Thomas (Senior Supervisor)

Desi (JV Senior Engineer)

Peter (JV Superintendent) Thomas (Senior Supervisor)

‐ ‐

• • Ensure work assess is planned. Ensure adequate access for work mobilisation  and public access. Only competent lifting crew is allowed to  involved in mobilisation. PTW‐Lifting approved prior unloading. Provide proper exclusion zone to segregate  work and public. Provide warning signs. Provide blinker lights to alert night motorist  and /or pedestrian. Ensure footage is firm and level at all times. Never drag load. Lift vertically.

Action Owner

Mitigation Measure

Risk 

Fall from  Height

Activity

RC works

4. RC Work– Risk mitigation

Working at  edge  Temporary  Construction  Openings Penetration  covers not  secured

Hazard  Cause

• •

‐ ‐

Milan (JV Project engineer) Milan (JV Project engineer)

Peter (JV Superintendent) Peter (JV Superintendent) Peter (JV Superintendent) Peter (JV Superintendent) Peter (JV Superintendent) Peter (JV Superintendent)

‐ ‐ ‐ ‐ ‐ ‐

• • • • • • Ensure edges are barricaded when possible Use of safety harness Construction openings to be secured Penetration covers to be cast with wire mesh Proper access/ ladders/ platforms as provided Placing of signages to warn fall from height  locations Retaining Wall to be cast (Roof Slab level) Guard Rail to be installed (Concourse level and  below)

Action Owner

Mitigation Measure

TYPICAL EXAMPLE OF  CONSTRUCTION OPENINGS  AND REQUIREMENT FOR  EDGE PROTECTION

Guard rail

Retaining wall

4. RC Work– Risk mitigation

22

Asphyxiation – Confined  space

RC works

Trip and fall

Risk 

Activity

Poor  illumination

Lack of  oxygen

Hazard  Cause

4. RC Work– Risk mitigation

Peter (JV Superintendent) Peter (JV Superintendent)

‐ ‐

•

Thomas (Senior Supervisor) Peter (JV Superintendent) Peter (JV Superintendent) Peter (JV Superintendent) Peter (JV Superintendent) Peter (JV Superintendent)

‐ ‐ ‐ ‐ ‐ ‐

• • • • • • • Adhere to confined spaces specification Control of personnel entering  Implement Confined Space permit systems Provide sufficient ventilation Conduct gas check every 4 hours Continuous air monitoring Appointment of qualified confined space  supervisor. Installation of lighting

Action Owner

Mitigation Measure

Risk 

Structural  failure Concrete Design

Activity

RC works

• • • •

•

• •

Peter (JV Superintendent) Peter (JV Superintendent) Milan (JV Project engineer) Peter (JV Superintendent)

Peter (JV Superintendent)

‐

Milan (JV Project engineer)

Peter (JV Superintendent) Peter (JV Superintendent)

‐ ‐ ‐ ‐

‐ ‐ ‐ ‐

Peter (JV Superintendent)

‐

• Formwork removal shall be approved by  formwork safety supervisor. Removal inspection checklist to be endorsed  Ensure concrete strength is achieved prior to  removal Temporary props are to be secured and not  removed unless approved by engineer Ground shall be compacted Cast lean concrete Formwork design shall be endorsed by PE Supervision by engineer to ensure installation  is as per shop drawings and according to  method statement and RA assessment Emergency response planning including  Contingency planning 

Action Owner

Mitigation Measure

Design/  installation  not being  certified by PE Installation  not as per PE  • shop drawings

Ground  foundation  unstable

Early  formwork  removal

Hazard  Cause

4. RC Work– Risk mitigation

Wall System Formwork

4. RC Work– Risk mitigation

25

Temporary Propping as part of  Design (Stairshaft landing, bottom up  construction) Scaffold System

End

Minutes Title: Monthly Risk Register Workshop No 6 Date:17 Aug 2017 Time: 2.00pm--3.30pm Held at: T309 LTA Level 2 Meeting Room

Chaired by: Jong Hua Kwan/ Tommy Lee Minuted by: Tommy Lee Distribution date: 5 Sep 17

Attendees list See attached

Apologies list

Page 1 of 3

Minutes ITEM

MATTERS DISCUSSED

1.0

Introduction

ACTION

Risk Workshop will be on 3 months look ahead activities. The complete flow of the process will be demonstrated via a short slide presentation

Info

The project superintendent will provide the necessary information required to mitigate risks on the above.

2.0 2.1

2.2

2.3

Slide presentation on 3 monthly look ahead - Aug - Oct Peter/ Jong 17 T309P informed that the incident relating to T309 project on hitting the LV cable was a case study between LTA/SPPG.

Drawings showing Site Services and Utilities should be split into three drawings: Respectively, Utilities (agencies), Site Services- Electrical, Site Services- Water. These drawings shall be distributed to all parties and place it on site.

T309P informed JHZH on the following items:

Note

JHZH

JHZH

a) Package 1 and 2 risks shall be combined as 1 risk register. b) To present/include the programme risks for the next meeting. c) Action owner shall be specific personnel to be included in the risk register. d) T309/CNSS/997/002- Page 23, T309/CNSS/102/012- Page 9, to add in machinery mobilization and demobilization issues into the risk register. e) T309/CNSS/117/013- Page 17, to add material falling from Slab into risk register. f) T309/CNSS/100/008- Page 4, to address the risk/mitigation measures as per findings and lessons learnt from collapse of trench for EB 26 panel. g) T309/CNSS/999/008- Page 26, to address the risk/mitigation measures as per findings and lessons learnt from bentonite spillage incident happened on 17 Aug 17.

3.0

Any Other Matters: The next workshop topic will be based on activities for the next 3 months look ahead.

Page 2 of 3

INFO

Minutes ITEM

MATTERS DISCUSSED

4.0

Next Workshop

ACTION

The next monthly workshop will be discussed with T309P for a proposed date

Page 3 of 3

All / Info

T309/CNSS

T309/CNSS

100

100

ERSS for Temporary Work

008

007

T309/CDSS/100/008

T309/CDSS/100/007

Trenching

Lifting with crane

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

Instability of temporary works (trenches)

● Differential settlement between station ERSS ● Failure of loose material, equipment/ rebar cage ● Instability of working platform

Hazard

4

5 Hazard Cause

ERSS wall construction within F1 soil layer - F1 soil layer collapse - Trench stability

- Not identifying the behaviour and response of the ground and adjacent structures

Flawed design of temporary works - Inappropriate use / misinterpretation of design codes - Lack of understanding of design software and output - Incorrect information on adjacent structures - Temporary works design is incompatible with adjacent structures

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Doc no: T309-JHZH-RAR-PWD-RIS-0001

6

- Collapse of temporary works - Excessive movement/Collapse of adjacent structures - Injury or fatalities of public and Construction workers

- Collapse of temporary works - Collapse / damage of adjacent structures - damage of permanent works - Injury or fatality of construction workers or public

Impact

Risk Classes A 0 B 23 C 63 D 7 93

Package 1

V

V

V

F

7

C

C

C

Ri

8 Mitigation Measures

- Contractor to produce robust design - Appropriate design sensitivity - Specify minimum penetration of panels - Additional site investigation - Pre-qualify contractors - Emergency Response planning - Provide temporary strut with PE endorsement

- Review levels to be developed - Regular review of Instrumentation / monitoring e.g. LBs to monitor building movement, LGs for ground movement and IW or XYZ for ERSS. - Approved Permit to lift and lifting plan - Lifting Supervisor to ensure correct method of usage - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Avoid loading and unloading near edge of properties or access walkways - Low speed in lifting and lowering of material '- Signaller to communicate with crane operator during lifting and lowering operation - Lifting points to be identified, marked and approved

- Contractor to produce robust design - Approved Permit to lift and lifting plan - Lifting Supervisor to ensure correct method of usage - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Avoid loading and unloading near edge of properties or access walkways - Low speed in lifting and lowering of material '- Signaller to communicate with crane operator during lifting and lowering operation - Lifting points to be identified, marked and approved

Page 1 of 17

I

I

I

S

Initial Risk Category Ri

I

I

V

V

I

S

V

F

C

C

C

Ri

Residual Risk Category Rr

11

12

JHZH-PM - Regular review instrumentation reading - Perform probing and SI (SPT) at regular intervals - Perform Ground Improvements when necessary - Joint inspection between JHZHJV and QPS for every Dwall 1) Mild case (to read; less than 10% of total panel excavated volume) – Create an earth bund wall surrounding the affected panel, fill up the bund wall pool with bentonite to increase the bentonite head level. 2) Moderate case (to read; more than 10% of total panel excavated volume, without any visual ground/ platform depression) – Move the grabber and other unnecessary heavy equipment at least 20m away from the affected panel, and backfill the panel with LSS to the ground level by tremie method. 3) On a case by case basis for a severe case (to read; more than 10% of total panel excavated volume, with obvious visual ground/ platform depression) – Move all machinery away except excavator at least 20m away from the affected panel, and backfill the panel with LSS to the ground level by tremie method. After 24 hours of backfilling, conduct light cement grout beneath the depressed platform.

JHZH-SBM

JHZH-LE/SO

- Steel plate to ensure uniform loading of crane JHZH-PM weight and outrigger - Use of level indicator and inclinometer - Additional site investigation when necessary - Lifting zone to be barricaded before works commence 1) Mild case (to read; less than 10% of total panel excavated volume) – Create an earth bund wall surrounding the affected panel, fill up the bund wall pool with bentonite to increase the bentonite head level. 2) Moderate case (to read; more than 10% of total panel excavated volume, without any visual ground/ platform depression) – Move the grabber and other unnecessary heavy equipment at least 20m away from the affected panel, and backfill the panel with LSS to the ground level by tremie method. 3) On a case by case basis for a severe case (to read; more than 10% of total panel excavated volume, with obvious visual ground/ platform depression) – Move all machinery away except excavator at least 20m away from the affected panel, and backfill the panel with LSS to the ground level by tremie method. After 24 hours of backfilling, conduct light cement grout beneath the depressed platform.

*Action Owner

JHZH-LE/SO

Risk Owner

- Steel plate to ensure uniform loading of crane JHZH-PM weight and outrigger - Use of level indicator and inclinometer - Additional site investigation when necessary - Emergency Response planning including Contingency planning e.g. stop all excavation, ensure safe escape route for workers, additional temporary struts. - Lifting zone to be barricaded before works commence - Lift load by 300mm, hold for 3 seconds, all personnel 3m away Approved lifting plan, reviewed by LE and approved by PM - Lifting points to be identified and approved - Low speed in lifting and lowering - Material shall be stacked safely and within stacking limit and load - Safety zone established - Signaler to communicate with crane operator

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10

Summary of Residual Risk Classes A 0 B 0 C 78 D 15 93

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

The Risk Register is a "live document" and it will be the responsibility of all parties involved in the design, construction and commissioning of the T309 Initial Project and to ensure that all reasonable means and measures are put in place for the effective management of all the safety risks.to continue to identify new risks that arises.

e

Apr-17

Apr-17

Apr-17

Due Date By

Revision K 13 14

7 months

7 months

7 months

Risk Exposure Period

C

C

C

Target Risk Rating

Open

Open

Open

Status

Date: 16/08/2017 15 16

17 Remarks

011

012

100

100

T309/CNSS

T309/CNSS

T309/CDSS/100/012

T309/CDSS/100/011

T309/CDSS/100/010

010

100

T309/CNSS

T309/CDSS/100/009

009

100

T309/CNSS

Construction of ERSS for Utility Diversion

Construction of ERSS for Drain Diversion

Construction of ERSS

Construction of ERSS

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

Instability of temporary works (Utility Diversion ERSS)

Instability of temporary works (Drain Diversion ERSS)

Excessive ground movement of adjacent structures and utilities

Instability of temporary works (ERSS failure)

Hazard

4

5 Hazard Cause

6 Impact

Structural damage/deflection of existing structures - Damage to utilities - Traffic accidents with associated injuries - injuries to public or construction workers associated with ramp distress - Damage to road surfaces - Wall toe movement

- Damage to utilities - Damage to road surfaces

-Higher than expected lateral deflection of ERSS wall during excavations - Unforeseen ground conditions - Inappropriate removal of struts - Over-excavation - Excavation for the utilities laying/trench

- Unforeseen higher than designed surcharge

- Damage to utilities - Damage to road surfaces

- Unforeseen higher than designed surcharge

IV

IV

C

C

C

C

C

C

C

C

C

C

C

Ri

8 Mitigation Measures

- PE to ensure surcharge level to within acceptable loading

- Contractor to produce robust design - Method Statements to ensure safe working methods - Monitoring on site - Gather knowledge from people with relevant experience - Visual inspection

- PE to ensure surcharge level to within acceptable loading

- Method Statements to ensure safe working methods -Follow the PTW (e.g excavate) daily during work - Review design of sheet pile and provide COS. - Only certified and appointed welders are allowed to weld. - Method statement to ensure proper bracing is provided.

- Contractor to produce robust design - Method Statements to ensure safe working methods - Gather knowledge from people with relevant experience

- PE to ensure surcharge level to within acceptable loading

- Contractor to produce robust design - Method Statements to ensure safe working methods -Regular review instrumentation reading - Apply PTW (e.g. excavate) daily before commencement of work

- Calculate amount of bentonite level required

- Robust Contractor's ERSS system - Pre-qualify contractors

- Contractor to produce robust design - Appropriate design sensitivity

- Contractor’s Method Statements - Apply PTW (e.g. excavate) daily before commencement of work '- Emergency Response Planning including Contingency planning e.g. grouting of gaps - Additional site investigation

Page 2 of 17

III

III

III

III

IV

- Injuries to public or construction workers associated with ramp distress - Traffic accidents with associated injuries - Structure Integrity of sheet piles.

- Inappropriate removal of struts - Over-excavation - Excavation for the drain and damage ERSS - Sheet pile obstructed and not able to pile into required depth. -Poor quality weld and design of sheet pile bracing.

IV

III

III

III

IV

IV

IV

I

I

V

V

I

I

S

V

V

F

7 Initial Risk Category Ri

- Structural damage/deflection of existing structures - Damage to utilities - Injuries to public or construction workers associated with ramp distress - Damage to road surfaces - Wall toe movement

Structural damage/deflection of existing structures - damage to utilities - Traffic accidents with associated injuries - injuries to public or construction workers associated with ramp distress - damage to road surfaces - Wall toe movement

Package 1 Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

-Higher than expected lateral deflection of ERSS wall during excavations - Unforeseen ground conditions

- Unforeseen higher than designed surcharge

Higher than expected lateral deflection of ERSS wall during excavations - Unforeseen ground conditions - Inappropriate removal of struts - Over-excavation - Excavation of cut and cover tunnel

- Low bentonite level

Inadequate structural detail connection between - Collapse of temporary works strut, waler to ERSS walls / shafts / excavations - Excessive movement/Collapse of adjacent structures - Injury or fatalities of public and Construction workers - Contractor's ERSS design - Workmanship

- Groundwater drawdown

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

V

V

III

III

III

III

V

V

III

III

III

I

I

V

IV

IV

V

V

I

I

V

V

S

F

D

D

D

D

D

C

C

C

C

C

C

Ri

Residual Risk Category Rr

11

- No stockpiling

JHZH-PM

-Provide ground improvements when necessary JHZH-PM - Requirements to record penetration into competent stratum on installation -High quality site records -Bearing capacity checks for construction equipment - Installation of additional recharge wells & pressure relief wells as contingencies.

- No stockpiling

JHZH-PM

JHZH-SBM

JHZH-SBM

JHZH-CWM

JHZH-CWM

JHZH-PM - instrumentation/monitoring to monitor strut loads. - Daily physical inspection of strutting system

JHZH-CWM

JHZH-SBM

JHZH-PM -Statutory requirement for QP(Sup) to be responsible for supervision of temporary works. -Emergency Response planning including Contingency planning

JHZH-PM

JHZH-SBM

JHZH-SBM

JHZH-CM

JHZH-PM

JHZH-SBM

JHZH-CM

-Normal/ established procedures for staging the JHZH-PM works to protect adjacent utilities -Permit to remove strut system followed to prevent inappropriate removal of struts -Emergency Response planning including Contingency Planning

- No stockpiling

12 *Action Owner

JHZH-PM

JHZH-PM

Risk Owner

- Control of excavation opening to pouring time JHZH-PM

- High quality construction records - Ensure trench stability - Emergency Response planning

- instrumentation/monitoring to monitor strut loads. - Daily physical inspection of strutting system

-Emergency Response planning including Contingency planning -Instrumentation/monitoring to monitor strut loads. - Instrumentation/ real time monitoring - Perform probing and SI (SPT) at regular intervals - Sufficient vibration monitors with appropriate trigger levels to be installed. - Provision of recharge wells. -Provide proper recharging system -Provide proper filter gravel

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10

Apr-17

Oct-17

Apr-17

Apr-17

Apr-17

Apr-17

Apr-17

Apr-17

Apr-17

Apr-17

Mar-17

Due Date By

Revision K 13 14

7 months

13 months

7 months

7 months

7 months

7 months

7 months

7 months

7 months

7 months

7 months

Risk Exposure Period

C

C

C

C

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Open

Open

Open

Open

Status

Date: 16/08/2017 15 16 17 Remarks

T309/CNSS

T309/CNSS

100

100

014

013

N.A

NA

Construction of ERSS (Kingpost) for traffic decking

Construction of ERSS (Drainage diversion)

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

- Instability of temporary works (kingpost for traffic decking - ERSS) -Poor ground condition -Using of poor condition machinery - Noise pollution -Accidental dislodgement of kingpost during driving -Collision of machinery and site people.

Gaps in sheet piles

Hazard

4

5 Hazard Cause

- Poor design lead to undersize kingpost. - Poor workmanship. -Overloading of kingpost with other load not considered in the design. -Toppling of machinery resulting in damage to property. -Injury to surrounding people. -Structure failure of machinery.. -Old machinery and poor maintenance causing disturbance to nearby resident. - Carelessness and inexperience operator. Faulty vibro hammer.

- Supporting structure across the excavation due to lack of diversion corridor

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

- Collapse of temporary works - Collapse / damage of adjacent structures - damage of permanent works - Injury or fatality of construction workers or public

- Leakage through gap in the walls - Damage to services - Groundwater drawdown - Localized collapse of soil in the gap during excavation

Impact

Package 1

IV

C

C

Ri

8 Mitigation Measures

- Method Statements to ensure kingpost is constructed according to MS -JV engineer / QPS to supervise kinghpost construction work to esnure quality of workmanship. - Design to allow sufficient safety factor for structure interity of kingpost. -Access to be laid with hardcore and compacted. -I beam to be properly stacked and excluded. -Machine to be inspected and certified by AE. -Regular monthly maintenance of machineries - Work zone to be barricaded to prevent unauthorized entry - Used of tag line to control swaying of load. - Only allow skilled operator and experienced lifting team.

- Minimize gaps to minimum size required - Utilities diverted from excavation wherever possible - Instrumentation around gap area when necessary

Page 3 of 17

III

S IV

F III

Initial Risk Category Ri

7

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

V

III

S IV

F IV

D

D

Ri

Residual Risk Category Rr

11 Risk Owner

- During construction phase, ensure RA control measure are implemented - e.g. -Segregation of man and machines -Provide designated pedestrian access for wokers. - Provide adequate warning signs. - Provide proper barricades around bore hole. -Installed sound barrier - Used of silent piler - Refrain from working at night and weekend /PH - Additional sling tied to sheet pile and machinery as extra protection in case grabber gives way. - Access to be laid with hard-core and compacted. - kingpost to be laid on top of hard-core.

JHZH-PM

JHZH-PM - Reinstall sheet piles if there are gaps during installation - Emergency Response Planning including Contingency Planning (e.g. immediate removal works upon sighting of unfavaourable ground/wall movements) 1) Mild case (to read; less than 10% of total panel excavated volume) – Create an earth bund wall surrounding the affected panel, fill up the bund wall pool with bentonite to increase the bentonite head level. 2) Moderate case (to read; more than 10% of total panel excavated volume, without any visual ground/ platform depression) – Move the grabber and other unnecessary heavy equipment at least 20m away from the affected panel, and backfill the panel with LSS to the ground level by tremie method. 3) On a case by case basis for a severe case (to read; more than 10% of total panel excavated volume, with obvious visual ground/ platform depression) – Move all machinery away except excavator at least 20m away from the affected panel, and backfill the panel with LSS to the ground level by tremie method. After 24 hours of backfilling, conduct light cement grout beneath the depressed platform.

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10 12

JHZH-PM

JHZH-SBM

*Action Owner

Apr-17

Apr-17

Due Date By

Revision K 13 14

7 months

7 months

Risk Exposure Period

C

C

Target Risk Rating

Closed

Open

Status

Date: 16/08/2017 15 16 17 Remarks

102

102

102

102

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

102

102

T309/CNSS

T309/CNSS

102

Diaphragm walling T309/CNSS

007

006

005

004

003

002

001

NA

NA

N.A

T309/CDSS/102/004

T309/CDSS/102/003

T309/CDSS/102/002

T309/CDSS/102/001

Barrette pile test

Welding Works with Welding inverter

Welding Works with Oxygen acetylene and Welding inverter

Diaphragm walling

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

5

-Instability of ERSS wall trenches - Low shear strength in Marine Clay - Loose fills - Possible removal of buried obstructions - Presence of thick peaty layers - High pore water pressure in Marine Clay - Close proximity of adjacent activities such as jet grout piles or casting of nearby trench -Leakage of Bentonite from D wall -Poor Bentonite mixe.

Hazard Cause

6

- Structural damage/deflection of existing structures - Damage to utilities - Traffic accidents with associated injuries - Damage to road surfaces - Collaspe of D wall

Impact

Kentledge collapse

- Failure of jack, jack force is not locked in - Unbalance pressure force in jack

- Testing of D-wall

- Improper maintenance of welding set - Improper connection and damaged cables - welding set not fully protected from wet surfaces - Welding in open space during wet weather condition

- Injury to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Injury to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Injury to public or construction personnel - Delays - Claims -Reputation

IV

IV

IV

B

B

B

C

D

D

D

C

Ri

8 Mitigation Measures

- Contractor shall provide -uniform hydraulic pressure supply to all jacks to main balance force in test - Mechanical safe lock (safety valve) to lock pressure in jack during jack operation in case of pressure loss

- Test set up must get endorsement of PE

- PPE: Welding face shield, apron and gauntlet - Apply PTW (e.g. hot works) daily before commencement of work - Electrical wires to be secured above ground - Daily welding set checklist/ inspection - Certified welders - Reminder in Tool box meeting

- PPE: Welding face shield, apron and gauntlet - Proper housekeeping - Method Statements (e.g. - Close main value & flush hose line after usage) - Apply PTW (e.g. hot works) daily before commencements of works - Daily welding set checklist/ inspection - Fire extinguishers and fire blankets - Reminder in Tool box meeting '- Certified welders - Welding screen to contain sparks

- Specifying waterproofing details @ interface

- Use of adequate plant / equipment for diaphragm wall construction -Apply PTW (e.g. lifting) daily before commencements of works - Cage to be within lifting equipment capacity - Lifting points to be identified, marked and approved

- Emergency Response Planning including Contingency planning e.g. grouting of gaps - Method Statements to ensure safe working methods - Apply PTW (e.g. excavate) daily before commencement of work

- Method Statements to ensure safe working methods - Regular monitoring of critical structures - Stability calculations - Contingency planning e.g. (backfilling) in case of collapse, additional temporary struts - Trial panel - Raised guide walls - Control of bentonite properties (e.g. viscosity, sand content, PH value, density) - Visual inspection - Pre-qualify contractors -Apply PTW (e.g. excavate) daily before commencement of work - Deploy worker to monitor Bentonite level especially over week end.

Page 4 of 17

I

I

I

II

IV

- Injury to public or construction personnel - Delays - Claims - Damage to permanent and temporary works

Fire sparks, fire explosion - Inappropriate welding of struts - Inappropriate welding of Traffic Deck due to Gas leaks, hose damaged, fitting damaged - Inappropriate welding of Noise Barriers - Incompetent welder deployed

Electrocution due to electrical leak

III

V

III

III

V

V

II

S

IV

F

7 Initial Risk Category Ri

- Water ingress - Lost toe stability - Loss of fines - Settlement of structures

- Delay of works -Inappropriate diaphragm wall design - Inappropriate use / misinterpretation of design codes

Package 1 Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

Inadequate water tightness - Poor concrete compaction - Inadequate concrete cover and reduced durability due to honeycomb - Poor workmanship

Diaphragm wall cage too heavy to be lifted

Gaps in retaining systems Provision for services to pass through retaining -Cracking / leakage systems - Structural Damage - Waterproofing problems and associated repair

Excessive ground movement of adjacent structures and utilities

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

III

V

V

V

V

V

I

I

I

I

III

III

V

V

II

S

IV

F

C

C

C

C

D

D

D

C

Ri

Residual Risk Category Rr

11 Risk Owner

12

JHZH-SBM

JHZH-PM

JHZH-PM

- Provide physical barrier (interlocked properly) JHZH-PM and safety signs around test sites - Emergency Response planning including Contingency planning - Proper design of kentledge system - Pre-qualify the subcontractor - Approved Method Statement

JHZH-SBM

JHZH-SBM

JHZH-SO

JHZH-SO

JHZH-SBM

JHZH-PM

JHZH-PM

JHZH-SBM

JHZH-SBM

*Action Owner

JHZH-PM

-Monitoring of overall settlement and differential JHZH-PM settlement of the kentledge - Provide physical barrier (interlocked properly) and safety signs around test sites - Emergency Response planning including Contingency planning - Proper design of kentledge system - Pre-qualify the subcontractor - Approved Method Statement

-No welding work under rain weather/ wet surfaces - Monthly inspection of welding equipment - Apply Safe Work procedure - Electrical neoprene cable double insulated

- Remove flammable items (timber, canvas etc.. )from welding premises - Monthly inspection of welding equipment - Apply Safe Work Procedure - Implement PTW -Hot work

- High quality construction inspection and records - Method Statements to ensure safe working methods - Use of adequate plant/equipment for ERSS wall construction

- Adopt approved lifting plan - Ensure lifting equipment are inspected monthly - Lifting zone to be barricaded before works commence

- Proper post-cast for structure - Specifying waterproofing details @ interface

-Normal/ established procedures for staging the JHZH-PM works to protect adjacent utilities -Regular review instrumentation reading -Permit to remove strut system followed to prevent inappropriate removal of struts -No stockpiling against D-wall -Emergency Response planning including Contingency planning - Never start D-walling without having the cages ready.

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10

Mar-17

Mar-17

Oct-17

Oct-17

Oct-17

Oct-17

Oct-17

Oct-17

Due Date By

Revision K 13 14

7 months

7 months

13 months

13 months

13 months

13 months

13 months

13 months

Risk Exposure Period

C

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Open

Status

Date: 16/08/2017 15 16 17 Remarks

102

102

102

102

T309/CNSS

Pilling T309/CNSS

T309/CNSS

102

T309/CNSS

T309/CNSS

010

009

010

009

008

T309/CDSS/102/004

T309/CDSS/102/001

NA

NA

NA

Piling

D Wall & Excavation

Lifting with crane

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

5

- Injury and/or fatalities to public and construction personnel

- Wrong instruments specified

C

- Set up the correct trigger value by QP(D).

- Exchange instrumentation design with neighbour contractors to cover whole stretch and interface boundary with T308 & T310.

Instrumentation snd Monitoring Plan for T309

-Instability of ERSS wall trenches - Low shear strength in Marine Clay - Loose fills - Possible removal of buried obstructions - Presence of thick peaty layers - High pore water pressure in Marine Clay - Close proximity of adjacent activities such as jet grout piles or casting of nearby trench

- Design is not checked or back analyzed

- Anomalities or unexpected behaviour is not investigated

- Records of monitoring are falsified

- Site staff do not understand the results of monitoring

- Water ingress - Lost toe Stability - Loss of fines - Settlement of structures

V

D

- Use of adequate plant / equipment for ERSS wall construction

Page 5 of 17

III

- Method Statements to ensure safe working methods - Regular monitoring of critical structures - Stability calculations - Contingency planning e.g. (backfilling) in case of collapse, additional temporary struts - Trial panel - Raised guide walls - Control of bentonite properties (e.g. viscosity, sand content, PH value, density) - Visual inspection - Pre-qualify contractors - Apply PTW (e.g. piling) daily before commencement of work

- Regularly check the machine condition.

- Contractor to ensure site activity planning takes into account the results of the monitoring where necessary.

- QP(S)/QP(D) and Contractor to review monitoring results daily and QP(S)/QP(D) to promptly issue any necessary instruction regards progress of the works.

II

C

- Cage design must get endorsement of PE - Regular inspection of interface with good records - Lifting points to be marked, identified and approved - Engineer to be present to confirm lifting points prior liftng rebar cage. - Ensure moin load radius is taken into consideration when preparing lift plan.

- Damage of instrument

IV

II

B

- Approved PTW (e.g lifting) daily before commencement of work - Lifting Supervisor to ensure correct method of usage - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Avoid loading and unloading near edge of properties or access walkways - Low speed in lifting and lowering of material '- Signaller to communicate with crane operator during lifting and lowering operation - Lifting points to be marked, identified and approved - Approved Lifting plan - Material shall be stacked safely and within stacking limit and load

- Apply PTW (e.g. lifting) daily before commencement of work - Monthly inspection of lifting mechanisms - Lifting Supervisor to ensure correct method of usage - Colour coding all lifting mechanisms for validity and serviceability levels - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Lifting points to be marked, identified and approved - Approved Lifting Plan -Weekly boom down inspection with mechanics

- To ensure that Instrumentation and Monitoring Plan is implemented by the Instrumentation Contractor.

- Inadequare review of monitoring

- Structural damage/deflection of existing structures - Damage to utilities - Traffic accidents with associated injuries - Damage to road surfaces

IV

I

B

B

Ri

8 Mitigation Measures

- Frequency of readings is insufficient

- Ground heave / settlement or additional stresses on other structures

- Collapse of adjacent structures

- Insufficient coverage of instruments

- Instruments are faulty or not correctly calibrated

- Collapse of temporary works

IV

I

IV

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

S I

F

7 Initial Risk Category Ri IV

Insufficient monitoring during construction

Package 1 Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities -Crane topple -Tanish reputation

- Injury to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities - Rebar cage fall off during lifting process. - Crane damanged by swing load e.g. windscreen damaged by lifted rebar cage.

Inadequate water tightness - Poor concrete compaction - Inadequate concrete cover and reduced durability due to honeycomb - Poor workmanship

Excessive ground movement of adjacent structures and utilities

Instability or failure of D Walls due to insufficient monitoring during construction

6 Impact

- Poor design - Poor workmanship - Poor rigging method

- Improper securing of material/ equipment/ cages - Overloading of material/ equipment/ cages - Slight tilt in crane '- Sudden movement of crane boom

Failing of loose material/ equipment/ rebar cages

Instability of rebar cage (including cages for Lshape d-wall panel)

- Breakage of lifting chain - Breakage of lifting sling - Failure of brake motor/gear - Failure of sling/chain buckles and hooks - Overloading of carried loads over limited of design capacity - Unauthorized modification of lifting points -Inadequate rigging method.

Hazard Cause

Failure of lifting mechanism

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

V

IV

V

III

II

II

I

I

V

V

I

S

V

F

D

C

C

C

C

C

Ri

Residual Risk Category Rr

- High quality construction inspection and records - Method Statements to ensure safe working methods

- Regular review Instrumentation reading -Permit to remove strut system followed to prevent inappropriate removal of struts - Emergency Response planning - Review SI report and cross check at site - Provide water relief wells when necessary

- Monitoring value is reviewed by QP(S)/QP(D) as required.

- Set up trigger, alert value

- Instrumentation Plan

- Emergency Response planning including Contingency planning - Adopt 3X3 lifting principles. - Only R/S is allowed to give signal to crane operator.

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10 11

12

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-SBM

JHZH-SBM

JHZH-SBM

JHZH-LE/SO

JHZH-LE/SO

JHZH-PM

JHZH-PM

JHZH-LE/SO

*Action Owner

JHZH-PM

Risk Owner

Mar-17

Mar-17

Mar-23

Mar-17

Oct-17

Oct-17

Due Date By

Revision K 13 14

7 months

7 months

79 months

7 months

13 months

13 months

Risk Exposure Period

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Status

Date: 16/08/2017 15 16 17 Remarks

T309/CNSS

102

011

NA

Bored pile test

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

Kentledge collapse

Hazard

4

5 Hazard Cause

- Failure of jack, jack force is not locked in - Unbalance pressure force in jack

- Bored Pile testing

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

- Injury to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Injury to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

Impact

Package 1

F

IV

IV

B

B

Ri

8 Mitigation Measures

- Contractor shall provide -uniform hydraulic pressure supply to all jacks to main balance force in test - Mechanical safe lock (safety valve) to lock pressure in jack during jack operation in case of pressure loss

- Test set up must get endorsement of PE

Page 6 of 17

I

I

S

Initial Risk Category Ri

7

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

V

V

F

I

I

S

C

C

Ri

Residual Risk Category Rr

11 Risk Owner

- Provide physical barrier (interlocked properly) JHZH-PM and safety signs around test sites - Emergency Response planning including Contingency planning - Proper design of kentledge system - Pre-qualify the subcontractor - Approved Method Statement

-Monitoring of overall settlement and differential JHZH-PM settlement of the kentledge - Provide physical barrier (interlocked properly) and safety signs around test sites Contingency planning - Emergency Response planning - Proper design of kentledge system - Pre-qualify the subcontractor - Approved Method Statement

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10 12

JHZH-SBM

JHZH-SBM

*Action Owner

Mar-17

Mar-17

Due Date By

Revision K 13 14

7 months

7 months

Risk Exposure Period

C

C

Target Risk Rating

Open

Open

Status

Date: 16/08/2017 15 16 17 Remarks

105

105

T309/CNSS

T309/CNSS

003

002

T309/CDSS/105/003

T309/CDSS/105/002

T309/CDSS/105/001

Adjacent Structures or Buildings T309/CNSS 105 001

NA

T309/CDSS/103/001

103

Permanent Works T309/CNSS

012

001

102

T309/CNSS

Construction work nearby to adjacent structures or buildings

Construction work nearby stake holders

Construction work nearby to school

Construction of Permanent Works

Lifting with crane

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

5

- Breakage of lifting chain - Breakage of lifting sling - Failure of brake motor/gear - Failure of sling/chain buckles and hooks - Overloading of carried loads over limited of design capacity - Unauthorized modification of lifting points

Hazard Cause

- Improper securing of material/ equipment/ cages - Overloading of material/ equipment/ cages - Slight tilt in crane '- Sudden movement of crane boom

Excessive ground and building settlement

Damage / excessive settlement to buildings/structures: - Victoria School Access Bridge - 2-storey semi-detached houses at Kee Sun Ave - St. Andrew's Autism Centre - Elliot at The East Coast - Laguna Park Electrical Substation (Block 5000F) - 2-storey semi-detached houses at Elliot Walk - Opera Estate Canal & Culverts Interface with the public.

Stop or delay school operation. Interface with the public.

- Activation criteria and minimum head are not given

- Ineffectiveness of recharge well layout given in the A/E design '- Some recharge well points will not provide effective recharging due to their locations being far from the buildings to be protected - Filter may not be compatible with the existing ground conditions - Pile test and D-wall test

-Long term settlements - Scheduling of work planning

-Unforeseen ground conditions -Excavation works causing unforeseen settlements -Groundwater drawdown

-Proximity of schools has special implications, -Victoria school is boarding school) - Scheduling of work planning

Excessive settlement - Insufficient ground information available for (Victoria School bridge and design canal structures)

Failing of loose material/ equipment/ rebar cages

Crane topple / Hoisted load - Poor crane footage hit crane - Incompetent lifting team - Poor lift plan - Congested work environment

Failure of lifting mechanism

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

- Damage to utilities - Damage to property

- Disruption to the site activities during installation of recharge well - Blockage of the filter gravel - Excessive water flow rate provided by the pumping system but little recharging effect

- Claims - Damage to buildings/structures - Complains from the public - Injuring the public

- Damage to buildings/structures - Delays - Claims - Closure of roads - Injuries / fatalities of construction workers and public

-Noise disruption to schools -Pick up and drop off times Damaged - Complains from the public - Injuring the public

- Serviceability issue with the bridge

IV

IV

V

V

III

IV

IV

C

C

C

C

C

C

B

B

B

Ri

8 Mitigation Measures

-Activation criteria and minimum have been designed and indicated (Zone 1 to 3)

- Contractor's consultant has designed the recharging system, modified the configuration - Design of filter gravel has been provided

- Instrumentation / Monitoring - Reduce work inteface with public during peak hours

- Contractor’s Method Statements - instrumentation / monitoring - Real time monitoring - Specification of instrumentation and monitoring requirements by AE consultant - Strengthening and temporary propping when necessary - Additional site investigation

- Contingency planning, inspection and monitoring - Method Statements - Additional site supervision (e.g. traffic marshal) - Reduce work inteface with public during peak hours

- Provision of additional boreholes for bridge and canal design

- Approved PTW (e.g lifting) daily before commencement of work - Lifting Supervisor to ensure correct method of usage - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Avoid loading and unloading near edge of properties or access walkways - Low speed in lifting and lowering of material '- Signaller to communicate with crane operator during lifting and lowering operation - Lifting points to be marked, identified and approved - Approved Lifting plan - Material shall be stacked safely and within stacking limit and load

- Design and COS crane access - No Overloading at all times - Proper maintenance of crane - Only competent lifting team is allowed - Implemet Permit to lift - Include both Max. and Min load radius - Do not conduct lifting in congested work environment. - Provide exclusion zone and Provide warning signs. - Provide sufficient tag lines

- Apply PTW (e.g. lifting) daily before commencement of work - Monthly inspection of lifting mechanisms - Lifting Supervisor to ensure correct method of usage - Colour coding all lifting mechanisms for validity and serviceability levels - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Lifting points to be marked, identified and approved - Approved Lifting Plan

Page 7 of 17

III

III

I

I

IV

III

I

I

IV

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

I

S

IV

F

7 Initial Risk Category Ri

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

Impact

Package 1 Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

IV

IV

V

V

III

IV

III

III

I

I

IV

III

I

I

V

V

I

S

V

F

C

C

C

C

C

C

C

C

C

Ri

Residual Risk Category Rr

11

- Provide proper recharging system - Provide proper filter gravel - Instrumentation/ Monitoring of settlement - Additional Site investigation

- Emergency Response planning - Provide proper recharging system - Provide proper filter gravel - Instrumentation/ Monitoring of settlement - Additional Site investigation - Control of bentonite pressures

- Perform ground improvements when necessary

-Emergency Response planning including Contingency planning -Instrumentation/monitoring to monitor strut loads. - Instrumentation/ real time monitoring - Sufficient vibration monitors with appropriate trigger levels to be installed. - Provision of recharge wells. -Provide proper recharging system -Provide proper filter gravel

12

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-SBM

JHZH-SBM

JHZH-SBM

JHZH-SBM

JHZH-SBM

JHZH-SBM

JHZH-LE/SO

JHZH-LE/SO

JHZH-PM

JHZH-PM

JHZH-LE/SO

*Action Owner

JHZH-PM

Risk Owner

JHZH-PM - Proper planning and traffic control - Provide soundproof wall - Close communication with the school and be cognisant of critical times in the school calendar

- Emergency Response planning - Insturmentation and monitoring of settlement - Additional Site investigation when necessary

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

May-20

Oct-17

Oct-17

Oct-17

Due Date By

Revision K 13 14

79 months

79 months

79 months

79 months

79 months

45 months

13 months

13 months

13 months

Risk Exposure Period

C

C

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Open

Open

Status

Date: 16/08/2017 15 16 17 Remarks

105

105

T309/ CNSS

T309 / CNSS

005

004

NA

N.A

Traffic Diversion for Option 1C (Laguna Park)

Traffic Diversion around Victoria School

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

5

'- Lack of communication between LTA, main contractors, and sub contractors.

Motorist confusion

Noise

Complaints from stakeholder

Traffic jam / congestion

'- Lack of coordination between JHZHJV and subbies operation team

- Poor planning

-Public confusion

Workers hit by traffic

- Congested road leading to Victoria school - Construction activities in front of Victoria school - Heavy machinery stationed along Siglap Link - Heavy traffic from new egress to Marine Parade Road - Pedestrians jaywalking -Inadequate signage and poor traffic control measures -Unsafe traffic layout -Failure to carryout trial trench for UG services -Failure to barricade work area and provide banksman to guide vehicular movement on site -Failure to equip with proper PPE

Hazard Cause

Risk associated with Traffic Diversion -Unsafe traffic conditions, accident hot spot and vehicles crashing into site -Damaged to UG services -Noise and dust pollution

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

- Collision of construction and public vehicles - Fatality - Delays - Claims - Injury to public or construction personnel - Tarbish reputation

- Collision of construction and public vehicles - Delays - Claims - Injury to public or construction personnel

Impact

Package 1

C

C

Ri

8 Mitigation Measures

-Clear and advance notification to all stake holders - Sufficient and clear notification signage to motorist – e.g. VMS - Coordinate closely with relevant authority e.g. LTA - Organise “work session” to brief all relevant parties - Briefing session to be conducted with all relevant parties on personnel on process of diversion. - Apply for lane closure - Close lane in accordance with COP Traffic control - Put up sufficient advance warning signage - Brief TCP to all relevant person prior work start - Carry out traffic diversion off peak hours. - Inform NEA about late traffic diversion work Potential noise issue - Ensure workers put on reflective vest. - Traffic controllers to equipped with light batons

- Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan '- Guard rail or rigid barrier to be setup and interlocked properly - designated path for access by pedestrians '- Code of Practise of Traffic Control and Work Zone -Approval of temporary traffic diversion layout by TM -Traffic layout and signage to follow TCP -Submit PSR (road) for clearance -Ensure good visibility of signage --Apply permit to dig prior to start work -Conduct RA/ SWP briefing

Page 8 of 17

II

II

IV

S

F IV

Initial Risk Category Ri

7

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

II

II

V

S

F IV

C

C

Ri

Residual Risk Category Rr

11 Risk Owner

- Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan '- Guard rail or rigid barrier to be setup and interlocked properly - designated path for access by pedestrians '- Code of Practise of Traffic Control and Work Zone -Approval of temporary traffic diversion layout by TM -Traffic layout and signage to follow TCP -Submit PSR (road) for clearance -Ensure good visibility of signage --Apply permit to dig prior to start work -Conduct RA/ SWP briefing

JHZH-PM

JHZH-PM - To provide traffic marshals to direct traffic when necessary - To study provision of temporary traffic lights to faciltate passing of construction and public vehicles smoothly when necessary - Placement of cone or barrier during diversion without reduction in lane width -Desk top study of all utilities and carryout appropriate trial trench -Barricade work area and provide proper signage and warning to motorist and pedestrian. -Lane closure to avoid peak hours, applicable hours is 9:30-16:30 for daytime and 16:30-09:30 for night time closure -Flow chart indicating the flow of instruction enabling the lorry truck to enter the lane closure work area during soil removal or delivery of materials.

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10 12

JHZH-PM

JHZH-SBM

*Action Owner

Jul-17

Mar-23

Due Date By

Revision K 13 14

10 months

79 months

Risk Exposure Period

C

C

Target Risk Rating

Closed

Open

Status

Date: 16/08/2017 15 16 17

Further improvemen ts will be discuss in PSR roadworks

Remarks

106

106

106

106

106

106

106

109

Existing Utilities T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

Existing Conditions T309/CNSS

006

006

005

004

004

003

002

001

T309/CDSS/109/006

N.A

N.A

N.A

N.A

T309/CDSS/106/003

T309/CDSS/106/002

T309/CDSS/106/001

Excavation

Excavation for Utility Diversion Works

Excavation for Utility Diversion Works

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

Seawall obstruction

Damage to HV cable

Damage to LV cable

Damage to Water pipe

Limited Work Areas

Damage to utilities

Damage to utilities and disruption to services

Damage to submarine cable

Hazard

4

5 Hazard Cause

- Injury or fatalities of public and construction workers Unplanned excavation -Insufficient marking on site -Failure to conduct detection test

Abandon seawall

Accidental damage - Excavator hitting protection pipe

Accidental damage - Excavator hitting protection pipe

Accidental damage - Excavator hitting protection pipe

- Damage to the equipment used - Deep foundation and diaphragm wall are not constructed properly

- Voltage drop

- Property damage -

- Disruption to water supply - Low pressure water supply

- Work areas too restricted or efficient workings - Schedule delays - Work areas require significant temporary - Unsafe environment for construction personnel works for their establishment traffic congestion

-Diversion and support of utilities across excavation: - Water pipe - Power Grid cables - SP Telecom cables - Starhub cables

6 Impact

Disturbance to public

-Non coordinated inter-contract utility diversion, - Delay - Remote disruption -Unforeseen obstructions - Missing information from utilities agencies - Insufficient trial trenches

Insufficient information about cable location

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Package 1

IV

III

III

III

D

C

C

C

C

C

C

C

Ri

8 Mitigation Measures

- Additional trial trench and site investigation

- Bracket to be fabricated and installed according to design and use of correct material - Use of heavy duty flexible hose to protect cable - Additional cables to create slag and prevent tension '- Ensure team is at work zone within 1hour of issues - clear demarcation of work zone - Apply Utilities service damage plan and utilities preventation plan - Positive identification of utiltiies

- Bracket to be fabricated and installed according to design and use of correct material - Use of heavy duty flexible hose to protect cable - Additional cables to create slag and prevent tension '- Ensure team is at work zone within 1hour of issues - clear demarcation of work zone - Apply Utilities service damage plan and utilities preventation plan - Serve affect resident notice during water diversion works - Positive identification of utiltiies

- Bracket to be fabricated and installed according to design and use of correct material - Ensure team is at work zone within 1hour of issues - clear demarcation of work zone - Apply Utilities service damage plan and utilities preventation plan - Supply of water bag/ water tank during water disruption by PUB '- PUB Technician to supervise valve closing operation - Elbow joints to be haunched - Positive identification of utiltiies

- Buidling temporary decking for efficient road/land use - Detailed SHE procedure to enforce safety

- Ongoing co-ordination with relevant utility companies - Contractor's Method Statement - Approved NCE - Pre-qualify Contractors - Apply PTW daily before commencement of work -Thorough study of utilities drawings -Cable detections by qualified LCDW -Provide clear utilities marking on site -Provide A3 size drawing of utility plan -Apply permit to dig -Barricade work area while trenching -Contact relevant utility agency for any presence of unidentified utility -Always treat utility as `live’ if encountered -Only manual digging allowed for trial trench -Full time supervision during trial trench -No mechanical excavation within 3 meters from live utilities. - Only manual excavation allowed for trial trench digging. - Brief utilities plan in language understood by the workmen.

- Method Statements - Additional site investigation - Approved NCE

- To divert submarine cable away from the station box

Page 9 of 17

IV

III

III

III

III

I

V

III

III

I

S

III

V

F

Initial Risk Category Ri

7

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

III

IV

IV

IV

III

III

IV

IV

III

I

V

IV

III

I

S

IV

V

F

D

C

C

C

C

C

C

C

Ri

Residual Risk Category Rr

11

12

- Cross check at site - Laise with related authority about the information of seawall

-Close communication with utilities agencies -Identify clear markers for utilities locations lines and brief staffs, workers and subcontractors -Emergency Response planning including Contingency planning

-Close communication with utilities agencies -Identify clear markers for utilities locations lines and brief staffs, workers and subcontractors -Emergency Response planning including Contingency planning

-Close communication with utilities agencies -Identify clear markers for utilities locations lines and brief staffs, workers and subcontractors -Emergency Response planning including Contingency planning

- Efficient site utilization plan for each different working stage - Hire a professional road safety review learn and checking when necessary

JHZH-UE

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-UE

JHZH-UE

JHZH-PM

JHZH-PM

JHZH-UE

JHZH-UE

-Utility cable detection and trial trench should be JHZH-PM carried out to identify the alignment -Diversion out of the structure footprint -Emergency Response planning including Contingency planning -Close communication with utilities agencies -Cable detection -Properly mark the location of utilities and briefing site staffs, workers and sub-contractors -If unclear with the finding of services after reaching the 2m limit, conduct further detection to determine the presence of any services below. -Dimensions and depth of Trial Trenches recorded by Project Survey Team for As Build information Photo records of trial trench including any utility discovered are recorded

JHZH-PM

JHZH-UE

-Design protective measures and temporary support scheme for utilities across excavation -Close communication with inter-contract and utilities agencies -Identify clear markers for utilities locations lines and brief staffs, workers and subcontractors -Cable detection -Emergency Response planning including Contingency planning

JHZH-PM

*Action Owner

JHZH-UE

Risk Owner

- Divert submarine cable away from the station JHZH-PM box and identify the clearly marker

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10

Jan-17

Dec-18

Dec-18

Dec-18

Oct-17

Oct-17

Oct-17

Oct-17

Due Date By

Revision K 13 14

5 months

27 months

27 months

27 months

13 months

13 months

13 months

13 months

Risk Exposure Period

C

C

C

C

C

C

C

C

Target Risk Rating

Closed

Open

Open

Open

Open

Open

Open

Open

Status

Date: 16/08/2017 15 16 17 Remarks

T309/CDSS/110/005

Future developments or Addition & Alteration works 112 001 T309/CNSS T309/CDSS/112/001

005

T309/CNSS

110

T309/CDSS/110/004

Interface with Adjacent Contracts T309/CNSS 110 004

Future developments or Addition & Alteration works

Excavation

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

Clashes between railway structures and future underground infrastructure works and/or future above ground developments

Interfacing with adjacent contracts

Incompatible Interfacing with adjacent contracts

Hazard

4

5 Hazard Cause

6 Impact

- Unforeseen higher than designed surcharge

- Damage to utilities - Damage to road surfaces - Damage to property

-Proposals for future underground infrastructure - Incompatible construction techniques and developments in direct conflict with alignment and stations - Delay of works - Unaware of future infrastructure and developments proposals

Effect of T310 TBM tunnels on D-Walls subway - Excessive ground movement near Entrance C - Movement to adjacent structures

- Excessive ground movement Unappropriate or non-workable connection design at interface of bored tunnels and station - Movement to adjacent structures - Groundwater drawdown end walls - Waterproofing problem and associated repairs

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Package 1

V

V

V

V

F

C

C

C

C

Ri

8 Mitigation Measures

- PE to ensure surcharge level to within acceptable loading

- Contractor to review Development Interface Report in detail - Coordination meetings between interfacing designers - Coordination between all parties (Client, Contractor, designers)

- Coordination meetings between interfacing contractors and designers to be managed by Contractors - Construction Interface report by Contractor - Coordination between all parties (Client, Contractor, Designers)

- Coordination meetings between interfacing contractors - Construction Interface report by Contractor - Coordination between all parties (Client, Contractor, Designers) - Specifying waterproofing details @ interface

Page 10 of 17

II

II

I

I

S

Initial Risk Category Ri

7

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

V

V

V

V

F

II

II

I

I

S

C

C

C

C

Ri

Residual Risk Category Rr

- No stockpiling

- Close coordination with related parties

- Instrumentation and monitoring - Close coordination

- Emergency Response planning e.g. grouting - Methods Statement - Close coordination

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10 11

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

Risk Owner

12

JHZH-PM

JHZH-PM

JHZH-CM

JHZH-CM

*Action Owner

May-20

May-20

May-20

May-20

Due Date By

Revision K 13 14

45 months

45 months

45 months

45 months

Risk Exposure Period

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Status

Date: 16/08/2017 15 16 17 Remarks

118

Ground Improvements T309/CNSS 118

T309/CNSS

Construction Methodology T309/CNSS 117

001

9

009

T309/CDSS/118/001

T309/CDSS/117/010

T309/CDSS/117/009

Jet grouting

"L" shape D- wall cage installation - Tandam Lift

Lifting with crane

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

Ground improvement failure

●Collision of cranes ●Crane collapse or failure ●Toppling of crane ●Crane hit surrounding structures, eg silo ●Hoisted material hit crane ●D wall stich snap ●Hoisted material hit crane

●Crane collapse or failure ●Toppling of crane ●Crane hit surrounding structures, eg silo ●Hoisted material hit crane

Hazard

4

5 Hazard Cause

Inappropriate jet grouting methods

-Overloading of lifting equipment -Failure to observe safe work procedures -- Instability of working platform. - Failure of loose material equipment/ rebar cages - Lack of communication - Inadequate supervision and control - Unplanned and poor control of crane movement - Substandard lift plan

-Overloading of lifting equipment -Failure to observe safe work procedures -- Instability of working platform. - Failure of loose material equipment/ rebar cages - Lack of communication - Inadequate supervision and control - Unplanned and poor control of crane movement - Substandard lift plan

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

- Collapse of ground - Injury or fatality of construction workers and public - Waterproofing problems and associated repair - Damage to buildings - Delay of works - Movements of adjacent structures

-Injury to site staff -Delay to construction -Damage to property

-Injury to site staff -Delay to construction -Damage to property

Impact

Package 1

V

IV

IV

F

C

C

C

Ri

8 Mitigation Measures

- Contractor to produce robust design - Jet grouting trials - Specifying waterproofing details @ interface - Instrumentation / Monitoring e.g. LBs to monitor building movement, LGs for ground movement and IW or XYZ for ERSS. - Additional site investigation and geophysics

- Provide support plates for firm support - Apply PTW (e.g. lifting) daily before commencement of work - Full extension of outrigger prior to lifting - Approved Lifting Permit - No workers shall be allowed to stand below suspended loads - Lifting Supervisor to ensure correct method of usage - Approved lifting plan (e.g. full extension of outrigger, approved and proper use of slings) - Lifting points to be marked, identified and approved -Safety zone established -Tag line with coloured flag to be installed along hoarding to warn operator from crossing the line when turning during lifting -Tag line with coloured flag to be installed at the top of bentonite tank to warn crane operator and signal man to guide operator during crane movement. -Bentonite tanks near to Dwall will only be erected after the completion of Dwall. -To include min load radius in lift plan.

- Provide support plates for firm support - Apply PTW (e.g. lifting) daily before commencement of work - Full extension of outrigger prior to lifting - Approved Lifting Permit - No workers shall be allowed to stand below suspended loads - Lifting Supervisor to ensure correct method of usage - Approved lifting plan (e.g. full extension of outrigger, approved and proper use of slings) - Lifting points to be marked, identified and approved -Safety zone established -Tag line with coloured flag to be installed along hoarding to warn operator from crossing the line when turning during lifting -Tag line with coloured flag to be installed at the top of bentonite tank to warn crane operator and signal man to guide operator during crane movement. -Bentonite tanks near to Dwall will only be erected after the completion of Dwall. -To include min load radius in lift plan.

Page 11 of 17

II

II

II

S

Initial Risk Category Ri

7

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

V

V

V

F

II

II

II

S

C

C

C

Ri

Residual Risk Category Rr

11

JHZH-PM

JHZH-PM

Risk Owner

- High quality construction records and material JHZH-PM testing - Methods statement - Pre-qualify contractors - Regular review instrumentation reading of inclinometers and ground settlement markers in trial test and feedback main works - Emergency Response Planning including Contingency planning e.g. stop all excavation, ensure safe escape route for workers, additional temporary struts.

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Reminder in tool box meeting - Lifting zone to be barricaded before works commence -Provide adequate hardstanding /firm working platform -Put in place the lifting permit system and display the relevant details on site. -Ensure no overloading of crane -Signaler to communicate with crane operator -Lift load by 300mm, hold for 3 seconds, all personnel 3m away -Approved lifting plan, reviewed by LE and approved by PM -Lifting operation supervised by lifting supervisor -Banksmen to guide crawler crane movement, ensuring no tracking over drain, trench or uneven ground. -Lifting points to be identified and approved -Low speed in lifting and lowering -Material shall be stacked safely and within stacking limit and load -Authorization of all machineries movement from point to point -Establish a permit to move system for heavy machineries -A lockout /tagout system during maintenance and breakdown period of mchineries -Maincon to control all machineries movement on site with daily discussion during coordination meeting -Setting up a security management plan that involved site security to be aware of the delivery of materials and ensuring no material delivery during lunch time and peak hour

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Reminder in tool box meeting - Lifting zone to be barricaded before works commence -Provide adequate hardstanding /firm working platform -Put in place the lifting permit system and display the relevant details on site. -Ensure no overloading of crane -Signaler to communicate with crane operator -Lift load by 300mm, hold for 3 seconds, all personnel 3m away -Approved lifting plan, reviewed by LE and approved by PM -Lifting operation supervised by lifting supervisor -Banksmen to guide crawler crane movement, ensuring no tracking over drain, trench or uneven ground. -Lifting points to be identified and approved -Low speed in lifting and lowering -Material shall be stacked safely and within stacking limit and load -Authorization of all machineries movement from point to point -Establish a permit to move system for heavy machineries -A lockout /tagout system during maintenance and breakdown period of mchineries -Maincon to control all machineries movement on site with daily discussion during coordination meeting -Setting up a security management plan that involved site security to be aware of the delivery of materials and ensuring no material delivery during lunch time and peak hour

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10 12

JHZH-SBM

JHZH-LE

JHZH-LE/SO

*Action Owner

Jul-17

May-20

May-20

Due Date By

Revision K 13 14

10 months

45 months

45 months

Risk Exposure Period

C

C

C

Target Risk Rating

Open

Open

Open

Status

Date: 16/08/2017 15 16 17 Remarks

118

121

T309/CNSS

Fire and Explosions T309/CNSS

001

002

T309/CDSS/121/001

T309/CDSS/118/002

Construction works involving flammable or explosive materials

Construction works for ERSS or permanent walls

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

5 Hazard Cause

Fire or explosion during construction

-Encounter flammable materials - Breakage of buried services - Ignition of methane from peat layers - Contaminant gas - War relics/unexploded ordnances - Heavy vehicles carrying flammable materials may be driven into the construction site

Excessive deflection of Insufficient ground improvement / treatment ERSS or permanent walls works

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

- Injury or fatality of public or construction workers - Damage to existing structures and services

- Flooding of excavation - Collapse of temporary works and adjacent structures - Injury of public or construction personnel - Disruption of essential services - Delays - Claims

Impact

Package 1

C

C

Ri

8 Mitigation Measures

- Provision of appropriate plant - additional site investigation and geophysics when necessary - Gather knowledge from people with relevant experience - Apply PTW (e.g hot works) daily before commencement of work - Safety Datasheet and Warning signs and Emergency contacts on display - Reporting to Safety and Security Department

- Contractor to produce robust Design - Method Statements to ensure safe working methods - Robust ERSS Design - instrumentation / monitoring e.g. LBs to monitor building movement, LGs for ground movement and IW or XYZ for ERSS.

Page 12 of 17

I

II

V

V

S

F

Initial Risk Category Ri

7

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

I

II

V

V

S

F

C

C

Ri

Residual Risk Category Rr

- Proper and independent flammable materials storage and management - Emergency Response Planning including Contingency planning e.g. quick evacuation route - Permit to carry hazardous material

- Provide efficient geometric design and the road level to mitigate flooding - Witness the instrumentation reading - Regular review and analyse instrumentation reading - Emergency Response planning include Contingency planning, inspection and monitoring

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10 11

JHZH-PM

JHZH-PM

Risk Owner

12

JHZH-SO

JHZH-SBM

*Action Owner

Mar-23

Jan-18

Due Date By

Revision K 13 14

79 months

16 months

Risk Exposure Period

C

C

Target Risk Rating

Open

Open

Status

Date: 16/08/2017 15 16 17 Remarks

122

994

994

Flooding T309/CNSS

Site set up T309/CNSS

T309/CNSS

002

001

002

NA

NA

T309/CDSS/122/001

4

5 Hazard Cause

MEWP topple

Hit by fallen object

Fall from height

Noise Barrier structural failure

6

- Collapse of temporary works - Excessive movement / Collapse of adjacent structures - Injury or fatalities of public and construction workers

-Interrupted construction, -Delays, -Environmental pollution

Impact

-Damage to own and public properties (Claims) - Injury or fatalities of public and construction workers

Old machinery and poor maintenance causing disturbance to nearby resident

Installation of sheet piles Noise pollution (foundation support for sound barrier)

Installation of sheet piles Accidental dislodgement of -Carelessness and inexperience operator. (foundation support for sheet pile during driving - Faulty vibro hammer sound barrier)

Structure failure of machinery

Installation of sheet piles Using of poor condition (foundation support for machinery sound barrier)

-Serious injury to worker and property. -Stop work causing delay

-Disturbance to neighbouring resident -Hearing injury to workers

-Low productivity Job delay and behind schedule -Cost implication

-Serious injury to worker and property. -Stop work causing delay

Installation of sheet piles Poor ground condition (foundation support for sound barrier)

-Toppling of machinery resulting in damage to property. -Injury to surrounding people.

-Serious injury to worker and property. -Stop work causing delay -Damage to machineries

Installation of sheet Collision of machinery and piles Constraint of work area (foundation support for site people. sound barrier)

-Damage to underground services -Disruption to stakeholders Location of utilities not reflected in utility drawing -Penalty charges by authority -Stop work order by authority -Delay to work schedule

-Failure to provide fall protection provision - Failure to provide control - Poor footage - Over loading of MEWP

-

- Collapse of temporary works - Incorrect information on adjacent structures - Not identifying the behaviour and response of - Damage to own and public properties (Claims) - Injury or fatalities of public and construction the ground and adjacent structures workers

-Flawed design of temporary works - Inappropriate use / misinterpretation of design codes - Lack of understanding of design software and output - Temporary works design is incompatible with adjacent structures

Flooding from the Opera -Damage the canal or foundation during Estate Canal at Siglap Link construction, -Extreme flooding event; -Tidal fluctuation -Structural problem of the canal

Hazard

Installation of sheet piles Damage to utilities (foundation support for sound barrier)

Setting up of Noise Barriers

Construction works near Opera East Canal

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Package 1

IV

IV

IV

IV

IV

IV

B

C

C

B

B

C

C

C

C

C

Ri

8 Mitigation Measures

V

V

-Additional sling tied to sheetpile and machinery as extra protection in case grabber gives way -Ensure sheetpile is clamped tightly between the grabber jaws before hoisting up vertically for installation

V

V

V

V

I

II

II

I

I

II

II

II

V

V

II

I

S

V

V

F

C

C

C

C

C

C

C

C

C

C

Ri

Residual Risk Category Rr

11 Risk Owner

12

Daily pre operation check on grabber by operator before start of work

Regular maintenance regime in place

LOTO system applied during maintenance period

-Ground preparation completed with the issuance of COS from PE -Ensure no overloading of machinery (Load kept at 75% of SWL

Apply for permit to move for machinery movement from point to point

Cable detection by LEW

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-PM

JHZH-SBM

JHZH-SBM

JHZH-SBM

JHZH-SBM

JHZH-SBM

JHZH-SBM

JHZH-SBM

JHZH-SBM

- Strengthening of noise barrier when necessary JHZH-PM - Additional site investigations and localized ground improvement when necessary - Emergency Response planning including Contingency planning e.g. stop all excavation, ensure safe escape route for workers, additional temporary struts. - Approved Method Statement

-Enveloped MEWP work platform with scaffold JHZH-PM netting to contain material. Limit max. 2 person on MEWP. Max. weight 120kg. Firm and compacted ground for MEWP access. Provide adequate exclusion zone and signage. Provide banksman to ensure no authorised entry in to work zone.

JHZH-SBM

JHZH-SBM/ ECO

*Action Owner

JHZH-PM - Engage experienced and competent consultant to perform the design - Engage experienced and competent contractor - Emergency Response planning including Contingency planning e.g. stop all excavation, ensure safe escape route for workers, additional temporary struts. - Approved Method Statement

JHZH-PM - Provide efficient geometric design and the road level to mitigate flooding -Awareness of climatic conditions -Regular monitor of water level in Opera estate Canal -Emergency Response planning including Contingency planning

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10

-Installed sound barrier. -Used of silent piler. -Refrain from working at night and weekend/PH

-Machine to be inspected and certified by AE. -Regular monthly maintenance of machineries

-Access to be laid with hardcore and compacted. -Steelplate to be laid on top of hardcore. -Movement of machinery must be guided by benchemen

-Work zone to be barricaded to prevent unauthorized entry -Used of tag line to control swaying of load - Employed skilled operator and experienced lifting team

-Carry out cable detection and trial trench along the path of sheet piles. -Apply permit to dig prior to work start.

- Provision of Fall Protection Plan. - Establish PTW-Height system. - Provide proper access. - Provide adequate work platform. - Licensed MEWP operator. - Familiarisation briefing prior appointment.

- Perform further structural or geotechnical investigations e.g. coring, trial trenching - Apply PTW (e.g. welding) daily before commencement of work - Certified welder

- Sensitivity of design input parameters - Pre-qualify contractor - Apply PTW (e.g. welding) daily before commencement of work - Certified welder

- Method Statements - Additional site investigation -Confirmation with LTA on any specific flood protection measures required during construction

Page 13 of 17

I

II

II

I

I

II

II

II

IV

IV

II

I

S

IV

V

F

Initial Risk Category Ri

7

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

Due Date By

Revision K 13 14

79 months

79 months

79 months

79 months

79 months

79 months

79 months

79 months

79 months

79 months

Risk Exposure Period

C

C

C

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Open

Open

Open

Status

Date: 16/08/2017 15 16 17 Remarks

994

996

996

997

T309/CNSS

Vector Management T309/CNSS

T309/CNSS

Mobilization T309/CNSS

001

002

001

003

NA

NA

NA

NA

Traffic Diversion

Workers working on site

Setting up of Hoarding

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

5 Hazard Cause

Risk associated with Traffic Diversion -Unsafe traffic conditions, accident hot spot and vehicles crashing into site -Damaged to UG services -Noise and dust pollution

Transmission of Dengue and Zika

Mosquito bites on construction/ public personnel

6

- Collapse of temporary works - Excessive movement / Collapse of adjacent structures - Injury or fatalities of public and construction workers

Impact

- Transfer (delivery and lifting) material, plant and manpower -Inadequate signage and poor traffic control measures -Unsafe traffic layout -Failure to carryout trial trench for UG services -Failure to barricade work area and provide banksman to guide vehicular movement on site -Failure to equip with proper PPE

- Mosquito breeding - Mosquito bites

- Mosquito breeding - Mosquito bites

- Traffic jam - Injury to public or construction personnel - Claims - Delays

- Injury or fatality of public or construction personnel - Claims - Delays

- Injury to public or construction personnel - Claims - Delays

- Collapse of temporary works - Incorrect information on adjacent structures - Not identifying the behaviour and response of - Damage to own and public properties (Claims) the ground and adjacent structures

Hoarding structural failure -Flawed design of temporary works - Inappropriate use / misinterpretation of design codes - Lack of understanding of design software and output - Temporary works design is incompatible with adjacent structures

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Package 1

F

IV

IV

IV

IV

IV

C

B

B

C

C

Ri

8 Mitigation Measures

- Code of Practise of Traffic Control and Work Zone - Use of barrier and/or gate guards for exit/entrances to site -Approval of temporary traffic diversion layout by TM -Traffic layout and signage to follow TCP -Submit PSR (road) for clearance -Ensure good visibility of signage --Apply permit to dig prior to start work -Conduct RA/ SWP briefing -Desk top study of all utilities and carryout appropriate trial trench -Barricade work area and provide proper signage and warning to motorist and pedestrian. -Lane closure to avoid peak hours, applicable hours is 9:30-16:30 for daytime and 16:30-09:30 for night time closure

- Pest control '- Emergency Response planning - Vector control management - Additional supervision - Oiling in stagnant water and other respective areas - Provision of insect repellents to site staff

- Pest control - Emergency Response planning - Vector control Management - Additional supervision - Oiling in stagnant water and other respective areas - Provision of insect repellents to site staff

- Perform further structural or geotechnical investigations e.g. coring, trial trenching

- Sensitivity of design input parameters - Engage experienced and competent consultant to do the design - Engage experienced and competent contractor - Pre-qualify contractor

Page 14 of 17

II

I

I

II

II

S

Initial Risk Category Ri

7

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

IV

V

V

V

V

F

II

I

I

II

II

S

C

C

C

C

C

Ri

Residual Risk Category Rr

11 Risk Owner

JHZH-PM

JHZH-PM

JHZH-PM - Properly traffic control and signages with qualified traffic marshal - Clearly defined zones for accessible pathways and restricted areas - Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan - Emergency Response planning including Contingency planning, inspection and monitoring - Lifting zone to be barricaded before works commence - Placement of cone or barrier during diversion without reduction in lane width -Flow chart indicating the flow of instruction enabling the lorry truck to enter the lane closure work area during soil removal or delivery of materials.

- Regular inspection of site to identify and eliminate breeding sites - Misting

- Regular inspection of site to identify and eliminate breeding sites - Misting

JHZH-PM - Strengthening of hoarding when necessary - Additional site investigations and localized ground improvement when necessary - Emergency Response planning including Contingency planning e.g. stop all excavation, ensure safe escape route for workers, additional temporary struts.

JHZH-PM - Engage experienced and competent consultant to perform the design - Engage experienced and competent contractor - Emergency Response planning including Contingency planning e.g. stop all excavation, ensure safe escape route for workers, additional temporary struts.

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10 12

JHZH-SBM

JHZH-SBM/ECO

JHZH-SBM/ECO

JHZH-PM

JHZH-PM

*Action Owner

Mar-23

Mar-23

Mar-23

Mar-23

Mar-23

Due Date By

Revision K 13 14

79 months

79 months

79 months

79 months

79 months

Risk Exposure Period

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Closed

Closed

Status

Date: 16/08/2017 15 16 17 Remarks

T309/CNSS

T309/CNSS

997

997

3

002

N.A

NA

Lifting with crane

Lifting with crane

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

5

- Breakage of lifting chain - Breakage of lifting sling - Failure of brake motor/gear - Failure of sling/chain buckles and hooks - Overloading of carried loads over limited of design capacity - Unauthorized modification of lifting points

Hazard Cause

Sharp edge material being - Site personnel cut by sharp material during lifted/ lowered/ handled handling

- Improper securing of material/ equipment Failing of loose material/ equipment including heavy - Overloading of material/ equipment - Slight tilt in crane mchineries / equipment '- Sudden movement of crane boom - Early release of jack base / hydraulic jack out riggers

Crane topple / Hoisted load - Poor crane footage hit crane - Incompetent lifting team - Poor lift plan - Congested work environment

Failure of lifting mechanism

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title: 6

- Injury and fatality to construction personnel - Delays - Claims

II

IV

C

B

B

B

Ri

8 Mitigation Measures

- Store all sharp material into material cages when possible - Pack/ organize sharp material - Use of PPE (e.g appropriate safety gloves, long sleeves, helmet and safety boots and glasses)

- Approved PTW (e.g lifting) daily before commencement of work - Lifting Supervisor to ensure correct method of usage - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Avoid loading and unloading near edge of properties or access walkways - Low speed in lifting and lowering of material '- Signaller to communicate with crane operator during lifting and lowering operation - Lifting points to be marked, identified and approved - Approved Lifting plan - Material shall be stacked safely and within stacking limit and load - Always secure materilas/heavy machineries on lorry bed before release out riggers / hydraulic jack. - Do not stay in libne of fire at all times.

- Design and COS crane access - No Overloading at all times - Proper mainyenance of crane - Only competent lifting team is allowed - Implemet Permit to lift - Include both Max. and Min load radius - Do not conduct lifting in congested work environment. - Provide exclusion zone and Provide warning signs. - Provide sufficient tag lines

- Apply PTW (e.g. lifting) daily before commencement of work - Monthly inspection of lifting mechanisms - Lifting Supervisor to ensure correct method of usage - Colour coding all lifting mechanisms for validity and serviceability levels - Safety zone to establish and marked - Clear signages place to warn entry of unauthorized personnel - Lifting points to be identified and approved - Approved Lifting Plan

Page 15 of 17

I

IV

I

IV

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

I

S

IV

F

7 Initial Risk Category Ri

- Injury and fatality to public or construction personnel - Delays - Claims - Damage adjacent structures and utilities

Impact

Package 1 Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

I

II

IV

I

V

V

I

S

V

F

C

C

C

C

Ri

Residual Risk Category Rr

11

12

JHZH-LE/SO

- '- Identify sharp material and dipose (e.g. nails, JHZH-PM broken glasses) - Wrap sharp edges when possible

JHZH-LE/SO

JHZH-PM

JHZH-LE/SO

JHZH-LE/SO

*Action Owner

JHZH-PM

Risk Owner

JHZH-PM

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

- Adopt three 3s as a guide - Lifting load by 300mm - Hold for 3 seconds - All personnel 3m away from lifting operation - Lifting zone to be barricaded before works commence - Reminder in toolbox meeting

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10

Oct-17

Mar-23

Oct-17

Mar-23

Due Date By

Revision K 13 14

13 months

79 months

13 months

79 months

Risk Exposure Period

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Status

Date: 16/08/2017 15 16 17 Remarks

999

999

999

999

999

999

Other Hazards T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

006

005

004

003

002

001

T309/CDSS/999/006

T309/CDSS/999/005

T309/CDSS/999/004

T309/CDSS/999/003

T309/CDSS/999/002

T309/CDSS/999/001

4

Damage to construction works

-Traffic congestion - Unauthorized entry of personnel to site

Road vehicles entering construction site / excavations

Noise, dust and vibration

Hazard

5

Setting up of Noise Barrier

Traffic Diversion

-Occurrence of a natural disaster during construction - Flooding - Heavy rainfall causing significant ground water table rise

- Construction activities require frequent transport movements - Works at site with long working hours for 7 days a week

-Construction works in close proximity to the public and existing housing -Excessive noise due to construction

-Spoil removed to designated location remote Movement of heavy vehicles causing disruption from site to traffic movement

Noise Barrier and foundation

6

- Injury to public or construction personnel - Disruption of essential services - Negative PR - Delays - Claims

Impact

- Injury to public or construction personnel - Disruption of essential services - Negative PR - Delays - Claims

- Delay and accidents, - ECM issues, - Mosquito breeding, - Security problems

D

C

D

C

C

C

C

Ri

8 Mitigation Measures

- Method Statements - additional site investigation - Provision of Noise barrier - Monitoring of Noise - Noise control plan - Engage community regularly and gather feedback

- Method Statements -Additional traffic management

- Method Statements - additional site supervision - ECM Plan

- Robust ERSS design including flood barriers when necessary - Temporary groundwater controls and pumps within excavation - Specifying water proofing details @ interface

- Design and approved traffic diversions - Minimise traffic around construction sites - Use of barrier and/or gate guards for exit/ entrances to site

- Design and approved traffic diversions - Clear and good signages - Minimise traffic around construction sites

- Contingency planning, e.g. additional noise barriers, inspection and monitoring - Method Statements to ensure safe working methods - Installation of noise barriers - Noise level monitoring - Engaging community for feedback '- Noise, dust control plan

Page 16 of 17

III

III

III

V

IV

IV

I

V

- Flooding of excavation - Collapse of temporary works and adjacent structures - Injury or fatality of public or construction personnel - Disruption of essential services - Delays - Claims

II

III

S

II

IV

IV

F

7 Initial Risk Category Ri

IV

-Environmental pollution

Package 1 Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

- Complaint from nearby occupants - Complaint from LTA - Working time may be reduced with delay to programme

-Traffic congestion due to minimum diversions, - Injury to public or construction personnel drivers seeking alternative routes - Damage to temporary or permanent works

-Construction works in close proximity to the public -Excessive noise due to construction -Excessive noise due to bored and barette pile testing

Hazard Cause

Discharge into Canal from -Heavy rain construction - Insufficient control on site -Surface run off, construction materials Construction Works (bentonite, concrete, grout, near Drains and Canal maintenance/cleaning facilities)

Construction Works near Drains and Canal

Traffic Diversion

Construction Works near Residental area

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

V

IV

III

III

IV

I

V

IV

II

II

III

S

V

V

V

F

D

C

D

C

C

C

D

Ri

Residual Risk Category Rr

11

JHZH-PM

Risk Owner

12

JHZHSBM/CWM

JHZH-PM

JHZH-PM

JHZH-SBM

JHZH-SBM

JHZH-PM - To provide traffic marshals to direct traffic when necessary - To study provision of temporary traffic lights to faciltate passing of construction and public vehicles smoothly -Designated haul routes -Contingency planning, inspection and monitoring - Placement of cone or barrier during diversion without reduction in lane width - Minimize loud noise activity during evening and weekends - Monitor noise meters at designated intervals - Contingency planning, inspection and monitoring

JHZHSBM/CWM

JHZH-PM - Install additional EC measures (e.g. silt fences, nets) when necessary '- Regular inspection of site by ECO at affected zones - Contingency planning, inspection and monitoring

- Close communication with related authority - Emergency Response planning including Contingency planning e.g. quick evacuation route - Provide efficient geometric design and the road level to mitigate flooding

JHZH-SBM

JHZH-SBM

JHZH-SBM

*Action Owner

JHZH-PM - To provide traffic marshals to direct traffic when necessary - Clearly defined zones for accessible pathways and restricted areas - Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan - Guard rail or rigid barrier to be setup and interlocked properly - Code of Practise of Traffic Control and Work Zone - Placement of cone or barrier during diversion without reduction in lane width

JHZH-PM - To provide traffic marshals to direct traffic when necessary - Clearly defined zones for accessible pathways and restricted areas - Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan - Guard rail or rigid barrier to be setup and interlocked properly - Code of Practise of Traffic Control and Work Zone - Placement of cone or barrier during diversion without reduction in lane width

- Vibration control plan - Vibration monitoring

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10

Mar-20

Mar-23

Mar-20

Mar-23

Mar-23

Mar-23

Mar-23

Due Date By

Revision K 13 14

45 months

79 months

45 months

79 months

79 months

79 months

79 months

Risk Exposure Period

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Status

Date: 16/08/2017 15 16 17 Remarks

999

999

999

999

999

999

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

T309/CNSS

PM- Project Manager CM- Coordination Manager SBM- Station Box Manager CWM- Canal Works Manager LE- Lifting Engineer UE- Utility Engineer SO- Safety Officer ECO - Environment Control Officer

999

T309/CNSS

013

012

011

010

009

008

007

N.A

N.A

N.A

N.A

N.A

N.A

N.A

Operation of machineries / equipment

Recahrge well work

Lifting with Excavator (Pick and Carry)

Traffic Diversion

Traffic Diversion

Removal of sludge

Cleaning

3

Work Activity

2

Previous Hazard ID

1

Hazard ID Hazard No. Hazard Running number Code

5

-Pipe leakage and burst -Loose connection

-Pipe leakage and burst -Loose connection -Lose control of hose

Hazard Cause

- Engine catch fire - Hydraulic oil leakage - Unvoluntary movement of machines boom / arm. - Load bearing componant give way.

Water pipe. Power grid cables. Telecom cables. High tension cables.

6

-Damage of machinery -Injury of worker -Damage of materials

-Damage of machinery -Injury of worker -Damage of materials

- Traffic jams hindering construction vehicles - Bottlenecks hindering traffic speed - Crossed traffic and pedestrian circulation paths - injury to public and/or construction work

- Traffic jams hindering construction vehicles - Bottlenecks hindering traffic speed - Crossed traffic and pedestrian circulation paths - injury to public and/or construction work

'- Injury to public or construction personnel - Contaminate soil, groundwater and surface water

- Injury to public or construction personnel

Impact

- Overloading or over running of machineries / -Damage of machinery -Injury of worker equipment result in over heating. -Damage of materials - Hydraulic leak - Poor maintenance reguime - Misue of machineries or equipment

-Unplanned Drilling. - Insufficient marking on site. - Failure to conduct detection test.

-Uneven ground - Unauthorised lifting - Improper rigging -Overloading -Inexperience operator

-“A’ frame topple - Injury to public - Fingers / hand caught in rotating parts

-Damaged to :

-Uneven ground - Unauthorised lifting - Improper rigging -Overloading -Inexperience operator

-Toppling of excavator - Falling of load/ material

Risk associated with Traffic - Change to road condition due to delivering Diversion material to site

Risk associated with Traffic - Change to road condition due to construction Diversion work, poor line of sight - Changed traffic condition causes confusion to road users - Improper/ unclear signages - Improper/ unclear separation of pedestrians paths and work site ingress/ egress points - Pedestrians jaywalking

Sludge spill

Use of high ultra water jet

Hazard

4

CONTRACT T309 CONSTRUCTION OF SIGLAP STATION FOR THOMSON-EAST COAST LINE

Project Title:

Package 1

F

IV

IV

IV

IV

IV

IV

IV

B

B

B

B

C

C

C

Ri

8 Mitigation Measures

- Ensure maintenance regime is carried out properly. - Always equip machineries / equipment with valid fire extinguisher - Never misuse machineries / equipment. Use it as what it is intended for.

-Thorough study of utilities drawings. - Cable detections by qualified LCDW - Provide clear utilities marking on site - Provide A3 size drawing of utility plan - Apply permit to dig and implement “checklist for working near utility” - Barricade work area while trenching

- Ensure work assess is planned. - Ensure adequate access for work mobilisation and public access. - Only competent lifting crew is allowed to involved in mobilisation. - PTW-Lifting approved prior unloading. - Provide proper exclusion zone to segregate work and public. - Provide warning signs.

●The excavator designed for pick and carry operations must have load chart stating clearly the limitattions for picks and carry operation ●Tag line shall be used during operation ● Ensure the route of travel is firm and level ●Lifting supervisor to ensure the load is firmly secured and tied ●Benchman to guide excavator during the pick and carry operation

- Design stages of traffic diversion to allow construction to be carried out section by section - Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan - Safety barrier to be setup at designated storage zones - Proper signages display at prominent locations - Code of Practise of Traffic Control and Work Zone - designated path for access by pedestrians - Control unauthorized entry of personnel into loading/unloading zone during material delivery

- Design stages of traffic diversion to allow construction to be carried out section by section - Traffic elements (e.g speed bumps/ road markings/ warning signs) indicated on plan - Guard rail or rigid barrier to be setup and interlocked properly Proper signages display at prominent locations - Code of Practise of Traffic Control and Work Zone

- Competent staff - Provide safety warning signage to keep other works clear from work area - Provide safety access to treatment plant - Permit for handling of sludge - Provide emergency contact no.

- Assign two trained hydro jetting operators. - Rotate shift every alternate hours - Provide safety warning signage to keep other works clear from work area - Provide safety access to washing bay

Page 17 of 17

II

II

II

II

II

II

II

S

Initial Risk Category Ri

7

Diaphragm wall, bored piles, ground improvement and enabling works

Risk Register

V

V

V

V

V

II

II

II

II

II

II

II

V

V

S

F

C

C

C

C

C

C

C

Ri

Residual Risk Category Rr

11

JHZH-PM

JHZH-PM

Risk Owner

JHZH-PM

JHZH-PM - Ensure fire extingisher is checked on a monthly basis - Monitor mechnais attendance for maintenance closely -

-Contact relevant utility agency for any presence JHZH-PM of unidentified utility Always treat utility as `live’ if encountered Only manual digging allowed for trial trench Full time supervision during trial trench

- Provide blinker lights to alert night motorist and /or pedestrian. - Ensure footage is firm and level at all times. - Never drag load. Lift vertically.

-AE to examine the lifting capacity of excavator JHZH-PM and issued the certification for the lifting. -Pick and carry operation is guided in SS536 : 2008

JHZH-PM - To provide traffic marshals to direct traffic when necessary - To study provision of temporary traffic lights to faciltate passing of construction and public vehicles smoothly - Placement of cone or barrier during diversion without reduction in lane width

JHZH-PM - To provide traffic marshals to direct traffic when necessary - To study provision of temporary traffic lights to faciltate passing of construction and public vehicles smoothly - designated path for access by pedestrians - Placement of cone or barrier during diversion without reduction in lane width

- Contain and handle spillage (e.g. excavate spill site and treat with dry sand, temporary diking) immediately - Contact additional emergency services when necessary

- Assign safety supervisor when possible at work place to ensure operation is safe - Barricade work area to prevent unauthorized access and display warning signage.

Future Actions

PREPARED BY TOMMY LEE/ HUA KWAN JONG 9 10 12

JHZH-LE/SO

JHZH-SBM

JHZH-SBM

JHZH-LE/SO

JHZH-SBM

JHZH-SBM

JHZH-SO

JHZH-SO

*Action Owner

May-23

May-23

May-23

Mar-23

Mar-23

Mar-23

May-20

Mar-23

Due Date By

Revision K 13 14

79 months

79 months

79 months

79 months

79 months

79 months

45 months

79 months

Risk Exposure Period

C

C

C

C

C

C

C

C

Target Risk Rating

Open

Open

Open

Open

Open

Open

Open

Open

Status

Date: 16/08/2017 15 16 17 Remarks

particularly to workers on site

2) To cascade the risk and mitigation measures to all parties concerned, 

that may arise.

1) To identify the on going major works activities and potential risk hazards 

Objectives of this workshop:

a) b) c) d) e) f)

Guide wall and Dwall Sheetpile installation Noise barrier erection Bored pile load test Soil Investigation Tree cutting

1)The on going major works activities are:

Mitigation Measures: 1) Provide proper barricade/ railing 2) Install proper ladder with handrail 3) Standby water pump during raining season 4) Conduct daily toolbox meeting and ensure proper PPE with gloves to prevent hand injury due to sharp object 5) Protruding nails to be removed during demoulding of formwork. 6) End treatment to all exposed rebar  7) Step ladder to have handrail on both sides

Construction of Guide Wall Hazard : 1) Fall into excavated pit 2) Flooding of pit during heavy downpour 3) Cut by sharp object, example rebar and protruding nails

Hazard: 1) Collapse of machine 2) Fallen into pit 3) Lowering of rebar cage 4) Connection and lowering of tremie pipes 5) Casting of dwall

Construction of Dwall

Mitigation: 1) Machinery must sit on hard ground with steel plates 2) Work area to be barricaded 3) Slow rotation of crane during hoisting of rebar cages 4) Provide tagline while hoisting of rebar cages to avoid violent  swinging 5) Ensure U‐clips are securely tightened before lowering of cages 6) Worker at platform while lifting of tremie pipes must wear full  hardness and secure to prevent falling from height 7) Banksman to guide concrete truck when reversing during casting 8) Incorporate the SWP and put in place a lifting plan 9) All workers to be trained in Work at height  10) Application of permit to move for heavy machineries movement 11) Approved Certificate of Supervision

Hazard

Damage to utilities

Activity

Installation of sheet piles

b) Sheetpiling – Risk and Mitigation

Location of utilities not reflected  in utility drawing.

Hazard Cause

Carry out cable detection and trial  trench along the path of sheet  piles. Apply permit to dig prior to work start.

Mitigation Measures

Collision of machinery and site people.

Installation of sheet piles

Constraint of work area  Negligence of operator Uneven ground Absence of lifting plan Failure to guide machineries movement

Hazard Cause

Ensuring the alignment and  verticality of the pile. 

Hazard

Activity

1) Sheetpiling – Risk and Mitigation

‐Work zone to be barricaded to prevent  unauthorized entry ‐Used of tag line to control swaying of  load. ‐Employed skilled operator and  experienced lifting team.  ‐Provision of lifting plan . ‐Full compaction and void filled with  quarry dust or mill waste.   ‐daily reminder during toolbox meeting      

Mitigation Measures

Poor ground condition

Installation of sheet piles

Access laid with hardcore and compacted

Hazard

Activity Toppling of machinery resulting in  damage to property Injury to surrounding people

Hazard Cause

Machine sitting on  sheet pile

Access to be laid with hard core  and compacted. Steel plates to be laid on top of  hard core. ‐Full compaction and void filled  with quarry dust or mill waste.   ‐daily reminder during toolbox  meeting                                                   

Mitigation Measures

Using of poor condition machinery

Installation of sheet piles

Maintenance service report, AE inspection  checklist and certificate

Hazard

Activity Structure failure of machinery

Hazard Cause

Machine to be inspected and  certified by AE. Regular monthly maintenance of  machinery 

Mitigation Measures

Accidental dislodge of sheet pile  during driving

Installation of sheet piles

Additional sling tied to sheet pile and machine

Hazard

Activity

Sub‐con approval system to select  skill operator Additional sling tied to sheet pile  and machine as extra protection  in case if grabber gives way.

Mitigation Measures

Sling will only be removed after sheet pile is fully  driven into the ground.

Negligent operator. Faulty vibro head

Hazard Cause

Hazard: 1) Fall from height 2) Faulty machine 3) Poor PPE

c) Noise Barrier Installation

Mitigation: 1) Only 2 person allowed in cabin of  boomlift and not exceeding SWL 2) Full harness and restrained to cabin 3) Workers trained in WAH procedure 4) Supervisor to check the condition of  harness worn by workers 5) Daily check on machinery before  start work 6) Protective shield to be worn during  drilling and cutting of metal. 7) Proper area set up solely for  welding, drilling and cutting of  metal

Bored pile test

Activity

Failure of  kentledge system

Hazard

•Testing area to be laid with hard core and fully compacted with 10 ton  roller

• Inadequate design • Poor ground  condition • No proper lifting plan • Improper loading of  kentledge • Inadequate  monitoring of  kentledge system

•Approved Method Statement

•Ensure loading of kentledge system is carried out in accordance with  the design

•PE’s design of kentledge system

•Provide physical barrier and safety signs around test site                      

•Monitoring of overall settlement and differential settlement of the  kentledge

•Proper lifting plan to be submitted with approval from PM and review  by Lifting Engineer.

•Contractor HSL to produce COS to confirm suitability of ground  preparation and kentledge set prior to pile test.

•Plate load test is to be carried out on test ground to determine the  bearing capacity of compacted ground

Mitigation Measures

Hazard Cause

d) Bored pile test – Risk and Mitigation

Bored pile test

Activity

Failure of kentledge system

Hazard •

d) Bored pile test – Risk and Mitigation

Improper loading of kentledge

Hazard Cause • •

self‐ retractable  lifeline to a  concrete  block 

Use of man‐cage to hoist rigger to top of kentledge set. Rigger to secure self‐retractable lifeline to a concrete block at  all times

Mitigation Measures

Bored pile test

Activity

Failure of kentledge system

Hazard •

Hazard Cause

Mitigation Measures

Surveyor monitoring settlement  daily

• Monitoring of overall settlement and differential  settlement of the kentledge

6 settlement  points  located at  platform to  monitor any  differential  settlement. 

Unequal and large settlement

d) Bored pile test – Risk and Mitigation

Barrette pile test

Activity

Failure of kentledge system

Hazard • • Inadequate design Improper loading of kentledge

Hazard Cause

d) Bored pile/Barrette pile test – Risk and Mitigation

•Approved Method Statement

•Ensure loading of kentledge system is carried out in accordance  with the design

•PE’s design of kentledge system

Mitigation Measures

Bored pile test

Activity

Failure of lifting  mechanism

Hazard

•Adopt approved lifting plan

•Overloading of carried loads over limited design capacity

Yellow for November

•Unauthorized modification of lifting points

•Lifting points to be identified and approved

•Failure of brake motor/gear

Mitigation Measures •Colour coding all lifting mechanisms for validity and serviceability levels

Hazard Cause

•Breakage of lifting chain/ sling

d) Bored pile test – Risk and Mitigation

Mitigation : 1) Qualified operator identified with photo displayed 2) Application of permit to dig 3) Daily check on machine

Hazard: 1) Inexperience operator 2) Faulty machine 

e) Soil Investigation

Hazard: 1) Fall from height 2) Eye and Ear injury 3) Hit by falling branches

f) Tree cutting

Mitigation: 1) Full harness and secured with additional strap to branch 2) Full PPE with goggle and ear plug 3) Barricade work area 4) Experience worker employed 5) Cutting from top down and in layer 6) Banksman to ensure no unauthorised entry

THANK YOU

Minutes Title: Risk Register Workshop Date: 1 Dec 2016 Time: 11am Held at: LTA level 2 meeting room

Chaired by: James Minuted by: Distribution date:

Attendees list See attached

Apologies list

Page 1 of 3

Minutes ITEM

MATTERS DISCUSSED

1.0

Introduction

ACTION

JHZH RMF reported the first Risk Register Workshop and there will be weekly workshop every Thursday, after the weekly progress meeting. Info LTA commented that all site engineers, safety, CM and PM should participate in this weekly workshop discussion. The objective of the workshop is to identify the on-going major works activities and potential risk hazards that may arise and to cascade the risk and mitigation measures to all parties concerned, particularly to workers on site. LTA encourage all present to come forward with any new risk that they encountered on site so that it can be discussed and recorded in the register. All mitigation measures shall also be discussed and recorded.

2.0

Slide presentation RMF presented a slide presentation on the risk hazards when working on:

James

Guide wall and D-wall Sheet pile installation Noise barrier erection Bored pile load test Soil Investigation Tree cutting 2.1

On guide wall/ D-wall construction, LTA(Vima) commented: i) proper storage of formwork ii) protruding nails should not be allowed to be freely thrown on the ground after form work removal. iii) end treatment must be carried out to any exposed rebar to prevent cut by sharp end of the rebar. Iv) construction of d-wall to have in placed a) COS b) SWP c) lifting plan d) permit to move

Page 2 of 3

JHZH

Minutes ITEM

MATTERS DISCUSSED

ACTION

On sheet pile installation, LTA commented: 2.3

i) the flow of full process of trial trenching prior to sheet piling work should be presented

JHZH

ii) there should be a sub-con approval system to select skill and experience operator On Noise Barrier installation, LTA commented: 2.4

JHZH

i) boom lift should not exceed the SWL ii) proper work area should be set up for welding work On Bored pile test, LTA commented: i) the settlement monitoring should be recorded and submitted for review daily

2.5

ii) the colour coated on the lifting gear faded with time, therefore it should be painted regularly

3.0

Any Other Matters: LTA commented the workshop to be kept in one hour duration and for subsequent session, individual engineer will be task to speak on the risk and mitigation findings in their respective zone.

4.0

JHZH

INFO

Next Meeting The next meeting will be scheduled on 8 Dec 2016 @ 11am

NEXT MEETING Date: Time: Location:

Page 3 of 3

All / Info

underground services.

3) All site personnel should be fully informed and clear with the work process concerning

carrying out trench excavation on site.

2) A flow chart to demonstrate the necessary steps to be taken to avoid any mishap while

measures to be adopted.

1) To identify the potential risk hazards concerning underground utilities and the mitigation

Objectives of this workshop:

Damaged to : -Unplanned excavation -Water pipe -Insufficient -Power grid marking on cables site -Telecom -Failure to cables conduct -High tension detection cables test

Locating of Utility services

Hazard Cause

Hazard

Activity

-If unclear with the finding of services after reaching the 2m limit, conduct further detection to determine the presence of any services below.

-Thorough study of utilities drawings -Cable detections by qualified LCDW -Provide clear utilities marking on site -Provide A3 size drawing of utility plan -Apply permit to dig -Barricade work area while trenching -Contact relevant utility agency for any presence of unidentified utility -Always treat utility as `live’ if encountered -Only manual digging allowed for trial trench -Full time supervision during trial trench

Mitigation Measure

Locating of Utility services prior to sheet piling work in Victoria School

JHZH’s UE

All Excavating contractor JHZH’s site engineer or supervisor

JHZH’s engineer, UE/Sub –con Requested by JHZH’s UE JHZH JHZH Excavating Contractor JHZH/sub con UE

Action Owner

Cable detection by LCDW

Production of utility drawing after completion of cable detection

Apply permit to dig

Commence trial trench up to a depth 1.5m

Contact relevant utility agency for any presence of unidentified utility

If unclear with the finding of services after reaching the 2m limit, conduct further detection to determine the presence of any services below.

Backfilled all trial trench once data/photos taken

1

2

3

4

5

6

7

Activity

Flow chart of utility work at Victoria School

JHZH site engineer Approval/Excavating contractor

LCDW/ Request by JHZH UE

JHZH UE

Excavating Contractor/Full time supervision by JHZH’s site engineer

Excavating Contractor

LCDW/ Requested by JHZH UE

Requested by JHZH’s UE

Action Owner

Permit to dig raised by who ever in charge

Indication of nature of work and duration

Completed by RMF together with the attendance of the team after briefing

Briefing will be carried out for: -working in new location -change of location(zone) -change of person in charge

To be completed by QPS

Commencement of cable detection work

Trial trench locations

Updated utility plan

Flow of underground utility work

Mitigation of In-Ground Utilities Prior to Sheet Piling Activities At Victoria School

Mitigation of In-Ground Utilities Prior to Sheet Piling Activities Description Step 1: Establish Site Boundary Obtain Design Alignment of sheet piles and commence desktop study of site environment

Responsibility Main Contractor (JHZH) 1. Utility Engineer 2. Area Site Engineer and/or Supervisor

Step 2: Information Retrieval to ascertain InGround Utilities a) Obtain a preliminary understanding of inground utilities present within and around site boundaries from sources such as Owner’s Construction Drawings, LCDW Reports (NCCDW), Utility Agency drawings, etc. b) Commission a LCDW survey to update Site Utilities Plan if information is lacking within the immediate site boundary

Main Contractor (JHZH) 1. Utility Engineer 2. Area Site Engineer and/or Supervisor 3. Licensed Cable Detection Worker (LCDW)

Plan showing alignment of sheet piles

Site utility Plan from LCDW report

Example of property owner’s construction drawing

Updated LCDW report to supplement previous reports

1

Excavating Contractor to commission cable detection in their immediate area of work.

Step 3: Commence on site investigation to identify signs of in ground utilities that may be present. These photos show the presence of the following in-ground utilities: a) PUB Water Inspection Chamber b) SingTel Manhole Pits c) SP Gas Valve Pit Site survey commenced

In this instance, SP Gas Valve Pit was noted to be inconsistent with Utility Agency drawings. A query was lodge with Singapore Power Gas to obtain more information. Note: A decision was later made to revise pile group locations to avoid the gas utilities.

Main Contractor (JHZH) 1. Utility Engineer 2. Area Site Engineer and/or Supervisor Excavating Contractor to familiarise themselves with existing utilities and their routing with Main Contractor.

Indicative signs of in ground utilities are noted

Mark in-ground utilities identified from site survey and desktop studies

Mark alignment of sheet piles

2

Step 4: On Site Review and Markings a) Mark out locations of sheet piling alignment and pile groups b) Also mark out locations of in-ground utilities identified from the above steps. Possible lines of utility conduits, cables and pipes were plotted on site with information obtained from desktop studies as well as on-site review

Main Contractor (JHZH) 1. Area Site Engineer and/or Supervisor 2. LCDW

Step 5: Establish if there are any Trial Trenches are required Locations of trial trenches were selected base on the following: a) Proximity of in-ground utilities to alignment of sheet piles (trench locations were selected to coincide on top of location of pile groups) b) Any indication of in-ground utilities on-site that are inconsistent when compared with desktop studies required investigation by trial trenching Note: All trial trenches were dug by hand, excavator shown in photo was utilised to clear above ground site vegetation. Any incomplete trial trench was protected with a steel plate as a safety measure. Factory wide Notice to Commence Excavation (NCE) was previously submitted.

Photos showing Site Preparation ahead of sheet piling activity

Site peg for pile group

3

Main Contractor (JHZH) 1. Utility Engineer 2. Area Site Engineer and/or Supervisor Main Contractor hired labour undertaking trial trenching were under full time supervision by JHZH Site Engineer

Step 6: Digging of Trial Trenches by Hand, with full time supervision by JHZH. Step 7: Recording of trial trench findings via: a) Photo and daily diary records b) Survey point by Project Survey Team for As Build Drawing

Findings from Trial Trench recorded

Step 8: Where there is discovery of In-Ground Utilities not previously ascertained or identified: a) Further scanning was conducted by LCDW to focus on a smaller area adjacent to trial trench b) Further trial trenching conducted to investigate route of discovered utility

Further scanning in a smaller area adjacent discovered utility

Scanning also undertaken inside trial trench

4

Lesson learnt: Utility Agency Plans and the limitations of cable detection are liable to errors, an experience team of Utility Engineers and LCDW is required to mitigate risks and ensure due diligence undertaken to avoid of clashing between sheet pile and undiscovered in-ground utility.

Main Contractor (JHZH) 1. RMF and QPS reviewed and give approval for trial trenching to commence 2. Area Site Engineer and/or Supervisor 3. Survey Team Main Contractor (JHZH) 1. Area Site Engineer and/or Supervisor 2. LCDW at the request of Utility Engineer

Step 9: Continuous updating of sheet pile grouping to avoid discovered in-ground utilities

Revised Sheet Pile Alignment after reiterations to avoid utilities

Permit to Dig

Sheet Piling Contractor submits the Step 10: Permit to Dig submitted and reviewed by request to dig Main Contractor Utility Engineer, Risk permit Management Facilitator, QPS and LTA. This is a construction hold point prior to commencing Main sheet piling. Contractor (JHZH) 1. Area Site Engineer and/or Supervisor 2. Design Engineer confirms the revision of sheet pile locations 3. RMF and QPS review and approved for sheet piling to commence Sheet Piling Contractor is responsible to maintain awareness and familiarise with in-ground utilities throughout the entire process

Step 11: Commence sheet piling activity only after hold point is released by review and approval of Permit to Dig.

5

Sheet Piling Contractor lay steel plates to mitigate the influence and impact of track vehicles over any nearby utilities

Minutes Title: Risk Register Workshop No 2 Date: 8 Dec 2016 Time: 11am Held at: LTA level 2 meeting room

Chaired by: James Minuted by: Distribution date:

Attendees list See attached

Apologies list

Page 1 of 3

Minutes ITEM

MATTERS DISCUSSED

1.0

Introduction

ACTION

JHZH RMF reported the first Risk Register Workshop MOM held on 1 Dec 2016 was submitted. Info As suggested by LTA to keep the session within one hour and to highlight one individual risk in each workshop, the risk and hazard of utility services at Victoria school was selected for discussion in this workshop The complete flow of the process will be demonstrated via a short slide presentation The utility engineer, Leonard will provide the necessary information required to carry out the detection of services in a safe manner.

2.0

Slide presentation on flow of work on utility services at Victoria School

James/ Leonard

Attached slides with amended comments added in RED

2.1

LTA commented JHZH should enhanced the traffic control with traffic marshal at Victoria School as there are students staying in the boarding house and may not be familiar with the access route due to the site work activities.

JHZH

2.2

LTA commented the current safety measures taken by T309 are much more stringent than the QPS enhance control measures for Permit to Dig by T305.

Info

New Permit to Dig(T305)

Old Permit to Dig(T305)

T309 standard of control for Permit to Dig

Produce a updated combined utility plan every month

Nil

Factory Wide Combined Utility Plan completed at onset of Project Work Area Specific Utility Plan reviewed in advance from commencement of any tasks at risk to in-ground utilities On site investigations to supplement desktop study of Utilities Plan and steps taken to ensure risks are well communicated to site supervision

Provide dimension of trial trench

Nil

Dimensions and depth of Trial Trenches recorded by Project Survey Team for As Build information Photo records of trial trench including any utility discovered are recorded

Page 2 of 3

Minutes ITEM

3.0

MATTERS DISCUSSED

ACTION

Indicate nearest utility distance on the drawing

Nil

Area Specific Utilities Plan is continuously updated with visits by Licensed Cable Detection Worker (LCDW) while the work activity is ongoing, LCDW will be activated to attend site when suspected utilities are encountered All utilities detected are marked on site with type and route of utility indicated on site

Risk assessment to be conducted when utility within 2m distance

Nil

Standard trial trenching undertaken to 2m for visual verification of suspected utility Risk assessment is undertaken continuously by Utility Engineer/ Site Engineer/ Supervisor/ QPS on site Full time supervision is undertaken while trial trenching

Not use excavator for digging the trial trench below 700mm

Nil

Mechanical trial trenching not permitted. Manual trial trenching to 2000mm

Any Other Matters: As the demolition of brick wall and tree clearing are commencing in Entrance A for drain diversion, it will be appropriate to highlight the risk hazards and mitigations in the next workshop.

4.0

INFO

Next Meeting The next meeting will be scheduled on 15 Dec 2016 @ 11am

Page 3 of 3

All / Info

Entrance A / Kee Sun Ave

Controlled Demolition

demolition work and the associated hazards and risks.

3) All site personnel should be fully informed and clear with the work process concerning

carrying demolition work on site.

2) A flow chart to demonstrate the necessary steps to be taken to avoid any mishap while

1) To identify the potential risk hazards concerning demolition work at Entrance A

Objectives of this workshop:

Hazard

-Eye and hand injury -Noise and dust pollution

Activity

Demolition of brick wall

-Flying debris -Failure to equip with proper PPE -Failure to barricade work area

Hazard Cause

Mitigation Measure

Action Owner

- Conduct RA/ SWP briefing Site - Pre-plant check of machinery engineer/technocrete - Barricade work area and protection set-up to prevent debris falling into drain. - Cutter rail track to be securely mounted on brick wall before cutting. - Operator to ensure that no one is near the cutting zone and the remote control cutter is activated. - Only experienced operator assigned to operate the remote control cutter can do the cutting of wall. - Similarly only qualified person can operate the remote control crusher and breaker. - Spray water during cutting, crushing and hacking to prevent dust pollution - Wear protective goggles and ear plug

Demolition of existing brick walls at Entrance A

RA/SWP Briefing

Checking of plant and machinery before starting of demolition work

Prevent debris from falling into drain during demolition.

Protection Set Up

- Operator to ensure that no one is near the cutting zone and the remote control cutter is activated. - Only experienced operator assigned to operate the remote control cutter can do the cutting of wall.

- Cutter rail track to be securely mounted on brick wall before cutting.

Cutting to Terminate Wall

Cutter rail track to be securely mounted on brick wall before cutting

Mounting of Track

Grab Machine Operated Remotely

- Similarly only qualified person can operate the remote control crusher and breaker. - Spray water during cutting, crushing and hacking to prevent dust pollution

Grab Machine Operated Remotely

- Similarly only qualified person can operate the remote control crusher and breaker. - Spray water during cutting, crushing and hacking to prevent dust pollution

- Similarly only qualified person can operate the remote control crusher and breaker. - Spray water during cutting, crushing and hacking to prevent dust pollution

Hacking Machine Operated Remotely

Bobcat Clearing Debris to Dump Container

Avoid discharging the hard core debris from height to prevent dust and loud noise when debris hit bin

Safety Barriers Demarcating Dumping Zone

THANK YOU

Minutes Title: Risk Register Workshop No 3 Date: 16 Dec 2016 Time: 11am Held at: LTA level 2 meeting room

Chaired by: James Minuted by: Distribution date:

Attendees list See attached

Apologies list

Page 1 of 2

Minutes ITEM

MATTERS DISCUSSED

1.0

Introduction

ACTION

JHZH RMF reported the 3rd Risk Register Workshop MOM held on 16 Dec 2016 was submitted on 17 Dec 2016

Info

The risk and hazard of demolition at Entrance A was selected for discussion in this workshop The complete flow of the process was presented via a short slide presentation The site engineer, Alfred provided the necessary information required to carry out the demolition of brick-wall in a safe manner.

2.0

Slide presentation on the demolition of brick-wall at Entrance A.

James/ Alfred

Attached slides with amended comments added in RED 2.1

LTA commented the following:

JHZH

1) Since the location is fixed, the Action Owner on the risk register should bear the name of actual person in charge. (slide 3) 2) Railing should be provided at edge of drain to prevent workers falling into drain during demolition. (slide 11) 3) Experienced operator controlling the remote control should be changed the appointed operator instead. (slide 3) 4) Bracing of undisturbed wall to provide stability during demolition (slide 7) 2.2

LTA would like to have the risk hazard on guide wall construction as a topic for discussion in the next workshop.

3.0

Any Other Matters: NIL

4.0

Next Meeting

INFO

The next meeting will be scheduled on 22 Dec 2016 @ 11am

Page 2 of 2

All / Info

Sheet Piling.

2) All site personnel should be fully informed and clear with the work process concerning 

mitigation measures to be adopted.

1) To identify the potential risk hazards concerning Sheet Piling at Entrance A and the 

Objectives of this workshop (no.5):

Existing Hoarding

Extension of Noise  Barriers (12m) w  SheetPiling

Two rows of sheet piles

Sheet Pile depth: 9m

Ingress/ Egress

Hazard 

Hazard  Cause

‐Submit lifting plan and machinery record prior to  start of operation ‐Provision of signalman and traffic controller to  guide machinery movement ‐Full compaction and void filled with quarry dust  or mill waste.  

Absence of  lifting plan

Failure to  guide  machineries  movement

Uneven  ground

‐Establish good communication at all times  between operator and signalman ‐Used of tag line to control swaying of load. ‐Provision of steel plate for machinery

‐Ensure work zone is organized with good housekeeping ‐Proper barricade and demarcation of work zone  to prevent unauthorized entry

Mitigation Measure

Negligence of  operator

Installation  Collision of  Constraint of  of sheet  machinery and  work zone  piles site people.

Activity

SheetPiling Risks and Mitigation Measures

Walter Lai

Walter Lai/ Killi

Walter Lai

Walter Lai

Walter Lai/ Jessica Ng

Walter Lai/ Jessica Ng

Action Owner

Ingress/ egress area to be covered with steel plate

SheetPiling Risks and Mitigation Measures

Machine access to be covered with steel plate

Accidental  dislodge of  sheet pile  during driving

Installatio n of sheet  piles

Negligent  operator Faulty vibro head

Hazard  Cause

Walter Lai

Walter Lai

Action Owner

Sling will only be removed after sheet pile is fully  driven into the ground.

Employ skilled operator and perform daily  checks prior to start of operation Additional sling tied to sheet pile and machine  as extra protection in case if grabber gives way.

Mitigation Measure

Additional sling tied to sheet pile and machine

Hazard 

Activity

Ensuring the alignment and verticality of the pile. 

SheetPiling Risks and Mitigation Measures

Damaged to : ‐Unplanned  excavation ‐Water pipe ‐Insufficient  ‐Power grid  marking on  site cables ‐Failure to  ‐Telecom  conduct  cables ‐High tension  detection  test cables

Locating  of Utility  services 

Hazard  Cause

Hazard 

Activity

‐If unclear with the finding of services after  reaching the 2m limit, conduct further  detection to determine the presence of any  services below.

Leonard Kok/ Tan WC/ Walter Lai Tan Hock Huat/ Tan WC Leonard Kok/ Tan WC Leonard Kok/ Tan WC Walter Lai Walter Lai Leonard Kok/ Tan WC

‐Thorough study of utilities drawings ‐Cable detections by qualified LCDW ‐Provide clear utilities marking on site ‐Provide A3 size drawing of utility plan ‐Apply permit to dig ‐Barricade work area while trenching ‐Contact relevant utility agency for any  presence of unidentified utility ‐Always treat utility as `live’ if encountered ‐Only manual digging allowed for trial trench ‐Full time supervision during trial trench 

Leonard Kok/ Tan WC

All Walter Lai Jessica Ng/ Thomas Ng

Action Owner

Mitigation Measure

SheetPiling Risks and Mitigation Measures

Hazard  Eileen Walter Lai

12m/6m noise barrier to be set up Good insulation on equipment, temporary  sound barrier (when necessary) Regular monitoring of noise level during  sheet piling activity

Insufficient Noise insulation  and noise  monitoring

Surface run‐ offs entering   drain Silt fence intact

Guna

Walter Lai/ Guna Guna/ Lina

Mr. Lau

Action Owner

Mitigation Measure

Hazard  Cause

Existing drain to be cleared regularly Installatio Flooding or  Heavy rain (Flash flood) Portable ECM to be in place n of sheet  clogging of  pile existing drain

Installatio Noise level is  n of sheet  above  pile acceptable  level

Activity

SheetPiling Risks and Mitigation Measures

Hazard 

Hazard  Cause

Installatio Gaps in sheet  Poor  n of sheet  piles workmanshi piles p

Activity Minimize gaps by interlocking sheetpile

Mitigation Measure

SheetPiling Hazards and Mitigation Measures

Walter Lai/ Jessica Ng

Action Owner

Hazard 

Hazard  Cause

Installatio Using of poor  Structure  n of sheet  condition  failure of  piles machinery machinery

Activity

Maintenance  service report,  AE inspection  checklist and  certificate

Action Owner

Machine to be inspected and certified by AE. Walter Lai Regular monthly maintenance of machinery 

Mitigation Measure

SheetPiling Risks and Mitigation Measures

Hazard 

Hazard  Cause

Mitigation Measure

Installatio Failure of  n of sheet  lifting  pile mechanism

Brake motor  failed Failure of  sling and  chain

Monthly inspection of lifting mechanism Colour coding all lifting mechanisms Safety zone to be established Lift load for 3 sec, 300mm and personnel 3  m away

Installatio Welding‐ Fire  Combustible Clear of combustible material  n of sheet  damage material pile Inappropriat Provide PPE‐ Welding face shield, apron,  gauntlet e welding  Daily welding set checklist/inspection rod Provision of fire blanket and fire  extinguisher

Activity

SheetPiling Risks and Mitigation Measures

Walter Lai/ Killi Walter Lai Walter Lai/ Crawford Walter Lai

Walter Lai Crawford Ang

Walter Lai

Walter Lai/ Jessica Ng

Action Owner

Hazard: 1) Fall from height 2) Faulty machine 3) Poor PPE

c) Noise Barrier Installation

Mitigation: 1) Only 2 person allowed in cabin of  boomlift and not exceeding SWL 2) Full harness and restrained to cabin 3) Workers trained in WAH procedure 4) Supervisor to check the condition of  harness worn by workers 5) Daily check on machinery before  start work 6) Protective shield to be worn during  drilling and cutting of metal. 7) Proper area set up solely for  welding, drilling and cutting of  metal

THANK YOU

Minutes Title: Risk Register Workshop No 5 Date: 2 Feb 2017 Time: 11am-12pm Held at: LTA level 2 meeting room

Chaired by: Tommy Lee Minuted by: Tommy Lee Distribution date: 8 Feb 17

Attendees list See attached

Apologies list

Page 1 of 3

Minutes ITEM

MATTERS DISCUSSED

1.0

Introduction

ACTION

Mr, Jong, JHZH Safety Manager and RMF joined in for the Risk Workshop no.5 which covers Sheet Piling at Entrance A.

Info

2.0

Slide presentation on sheet piling at Entrance A

Tommy

2.1

LTA noted to establish utilities with Entrance A and siglap park connector area, to ensure that all utilities are identified.

JHZH

2.2

It was noted that Lighting is adequate and will be placed at the hoarding and other designated location. 2.3

2.4

2.5 2.6

2.7

2.8

It was discussed that the sheet pile clearance area is approx. 3.5m and sufficient clearance is required for the vibro machine rotation shall be considered. The schedule for sheet piling and drainage excavation, including the sequence of work shall be made known to LTA and QPS.

Info JHZH

JHZH

Surveys shall be conducted to houses along Kee Sun Ave to access any potential issues during sheet piling.

JHZH

Peter highlighted that one main risk is to secure the 2 trees from toppling within the excavation area. Sheetpile may be driven on its side to secure the trees in position.

JHZH

Ingress for delivery of sheet pile is being delivered from Kee Sun Ave as originally planned with the use of lorry crane. Egress will be towards Marine Parade Road. LTA had emphasised the use of lorry crane for loading and unloading shall be assessed on a case by case basis.

Info

2.9

JHZH suggested the marking of red paint on the hoarding at the machinery operator eye level to give visible information to the operator the hoarding boundaries location.

2.10

Mobilization of the machinery for sheet piling will begin on 6 Feb 2017.

Info

2.11

LTA reminded that any inspection work involving QPS shall be duly informed to the QPS.

Info

QPS mentioned the need to use steel plates for the movement of the machinery. JHZH shall review on it.

Page 2 of 3

Info

JHZH

Minutes ITEM

MATTERS DISCUSSED

3.0

Any Other Matters:

ACTION

LTA reminded on the PD visit to happen on the 14th Feb 17. Housekeeping is essential. A monthly PGI inspection will be conducted on the 7th Feb 17.

4.0

Info

Next Meeting The next meeting will be scheduled on 9 Feb 17 @ 9am (tentative). The topic will be on drainage excavation for Entrance A. The presentation will be conducted by Mr. Jong.

Page 3 of 3

All / Info

drain excavation.

2) All site personnel should be fully informed and clear with the work process concerning 

and the mitigation measures to be adopted.

1) To identify the potential risk hazards concerning drain excavation activities at Entrance A 

Objectives of this workshop (no.6):

Existing Hoarding

Extension of Noise  Barriers (12m) w  SheetPiling

Drain size ‐ 1.5m wide,  2‐3m depth & 80+‐ m long

Drain excavation between  two rows of sheet piles

Ingress/ Egress

Damaged to :

Excavation  work

Water pipe. Power grid  cables. Telecom  cables. High tension  cables.

Hazard 

Activity

Failure to  conduct  detection  test.

Insufficient  marking on  site.

Unplanned  excavation.

Hazard  Cause

If unclear with the finding of services after  reaching the 2m limit, conduct further  detection to determine the presence of any  services below.

•

• • •

• •

Thorough study of utilities drawings Cable detections by qualified LCDW Provide clear utilities marking on site Provide A3 size drawing of utility plan Apply permit to dig and implement “checklist  for working near utility” Barricade work area while trenching Contact relevant utility agency for any  presence of unidentified utility Always treat utility as `live’ if encountered Only manual digging allowed for trial trench Full time supervision during trial trench 

• • • • •

Mitigation Measure

Drain Excavation Risks and Mitigation Measures

Tan WC LCDW Segar (ES Site Supervisor) Hari (ES Engineer)

Leonard Kok/ Tan WC

‐ ‐ ‐ ‐

Action Owner

Provide rigid barricade and warning signage. Provide proper access. Provide toe board. Provide adequate lighting if necessary. Never store material within 1 m from  excavation edge. Provide proper shoring (in this case sheet  pile) Never allow machineries to park close to  excavation trench.

• • • • • •

Excavation collapse

Poor shoring

Missing fall  protection provision

•

Put up extra support for the pine tree. Brief workers and excavator operator to be  aware of the hazard.

• •

Workers hit  by fallen pine  tree

Damaged  roots

Design and construct strutting work to  prevent soil movement. Pre‐con survey on potential infrastructure /  house.

Sub‐standard  • soil restrain  temporary  • work

Soil  movement  affecting existing  infrastructure

Mitigation Measure

Hazard  Cause

Hazard 

Excavation  Worker /  work material fall  into  excavation.

Activity

Drain Excavation Risks and Mitigation Measures

‐ ‐

‐ ‐

‐ ‐

‐ ‐

Segar (ES Site Supervisor) Jessica (JV Engineer)

Segar (ES Site Supervisor) Jessica (JV Engineer)

Segar (ES Site Supervisor) Jessica (JV Engineer)

Jessica (JV Engineer) Erin Rosli (SPRO)

Action Owner

Provide support for the pine tree

GI pipes

Pine tree

I beam

Drain Excavation Risks and Mitigation Measures

Ingress/ egress area to be covered with steel plate

Excavation  work

Activity

Establish good communication at all times  between operator and signalman Used of tag line to control swaying of load. Provision of steel plate for machinery Provision of signalman and traffic controller to  guide machinery movement Provide exclusion zone to control movement  of excavator.

•

• •

Negligence of  operator

Ensure work zone is organized with good housekeeping. Proper barricade and demarcation of work  zone to prevent unauthorized entry

•

Constraint of  work zone 

Failure to  guide  machineries  movement •

•

•

Mitigation Measure

Hazard  Cause

Collision of  machinery and  Uneven  site people. ground

Hazard 

Drain Excavation Risks and Mitigation Measures

‐ ‐

Segar (ES Site Supervisor) Jessica (JV Engineer)

Action Owner

Provide exclusion zone and banksman to prevent  unauthorised entry.

Drain Excavation Risks and Mitigation Measures

Excavation  works

Activity

Surface run‐ offs entering   drain

Heavy rain (Flash flood)

Poor  scheduling of  work. Poor  maintenance  of excavator.

Noise level is  above  acceptable  level

Flooding or  clogging of  existing drain

Hazard  Cause

Hazard 

• •

• • •

Exisiting drain to be clear regularly. Ensure ECM is functioning well. Provide sufficient manpower to maintain silt  fence. No stock pile on site. Cover any residue spoil.

‐ ‐ ‐

Guna (LV ECO) Segar (ES Site Supervisor) Jessica (JV Engineer)

Segar (ES Site Supervisor)

‐

• • • Carryout drain excavation during day time. Proper maintenance of excavator. Provide noise barrier to mitigate noise.

Action Owner

Mitigation Measure

Drain Excavation Risks and Mitigation Measures

Portable treatment plant commissioned to ensure silty  water are properly treated prior discharge into public  drain.

Drain Excavation Risks and Mitigation Measures

Sufficient manpower  deployed to ensure  silt are properly  maintain.

THANK YOU

drain excavation.

2) All site personnel should be fully informed and clear with the work process concerning 

and the mitigation measures to be adopted.

1) To identify the potential risk hazards concerning drain wall bracing activities at Entrance A 

Objectives of this workshop (no.7):

Existing Hoarding

Extension of Noise  Barriers (12m) w  SheetPiling Ingress/ Egress

Drain size ‐ 1.5m wide,  2‐3m depth & 80+‐ m long

Drain excavation between  two rows of sheet piles

Drain wall bracing Risks and Mitigation Measures

Drain wall bracing Risks and Mitigation Measures

Drain wall bracing Risks and Mitigation Measures

Hazard 

Crane topple

Activity

Lifting  work

Ensure crane work within load radius and  within max. capacity. Make known weight of I beam to lifting team. Ensure monthly mechanics inspection Conduct weekly boom down with mechanics Carry out daily inspection by operator Only appointed and certified R/S and LS are  allowed to carryout lifting work. Enforce on PTW – lifting

• • • • •

Failure in LM  mechanical  part

Incompetent  lifting team

No lifting plan

•

• •

Overload

Poor ground  condition.

Design and COS crane access. Appoint LE to inspect ground condition after  adverse weather. Provide steel plates on compacted ground.

Mitigation Measure • •

Hazard  Cause

Drain wall bracing Risks and Mitigation Measures

‐ ‐

Jessica (JV Engineer) Segar (ES Site Supervisor)

Action Owner

•

•

Hoisted load  too near to  public /  resident

Long bulky  load not  considered  for lift plan

Load in  contact with  crane

Reduce length of I beam Provide adequate tag lines to prevent load  from swing to public. Lift plan to include min. load radius RA to consider congested work area Always adopt 3X3 lifting principals 

• •

• • •

Deploy competent lifting team Provide tag lines to control movement of load Never place body part in line of fire

‐ ‐ ‐

‐ ‐

‐ ‐

Jessica (JV Engineer) Segar (ES Site Supervisor) Killi (JV Lifting Engineer)

Jessica (JV Engineer) Segar (ES Site Supervisor)

Jessica (JV Engineer) Segar (ES Site Supervisor)

Jessica (JV Engineer) Segar (ES Site Supervisor)

‐ ‐

• Only appointed and certified R/S and LS are  allowed to carryout lifting work. Provide exclusion zone and only authorised  personnel are allowed to entre. Provide adequate tag lines.

Action Owner

Mitigation Measure

Poor footage  • or missing tag  • lines •

Interface  with public

Body part  place in line  of fire

Poor rigging  method

Fallen I beam

Lifting  work

Missing tag  lines

Hazard  Cause

Hazard 

Activity

Drain wall bracing Risks and Mitigation Measures

Provide exclusion zone and banksman to prevent  unauthorised entry.

Drain wall bracing Risks and Mitigation Measures

Include min load radius in load chart

‐ Property             damaged Fire and  ‐ Injury to  explosion public or  workers

Welding  work

Hazard  Cause

Hazard 

Activity

• •

• • • • •

• • • • PPE: Welding face shield, apron and gauntlet Proper housekeeping Method Statements  Apply PTW (e.g. hot works) daily before  commencements of works Daily welding set checklist/ inspection Standby fire extinguishers and fire blankets Reminder in Tool box meeting Certified welders Remove flammable items (timber, canvas etc..  )from welding premises Monthly inspection of welding equipment Apply Safe Work Procedure

Mitigation Measure

Drain wall bracing Risks and Mitigation Measures

‐ ‐

Segar (ES Site Supervisor) Segar (ES Site Supervisor)

Action Owner

Welding work with fire screen, extinguisher and fire  watchman standby.

Drain wall bracing Risks and Mitigation Measures

No welding during wet weather.

THANK YOU

drain excavation.

2) All site personnel should be fully informed and clear with the work process concerning 

and the mitigation measures to be adopted.

1) To identify the potential risk hazards concerning drain excavation activities at Entrance A 

Objectives of this workshop (no.8):

Existing Hoarding

Extension of Noise  Barriers (12m) w  SheetPiling

Drain size ‐ 1.5m wide,  2‐3m depth & 80+‐ m long

Drain excavation between  two rows of sheet piles

Ingress/ Egress

Sequent 1

CLG904D

Soil truck

Sequent 2

Soil truck

Excavator EC290

Damaged to :

Excavation  work

Water pipe. Power grid  cables. Telecom  cables. High tension  cables.

Hazard 

Activity

Failure to  conduct  detection  test.

Insufficient  marking on  site.

Unplanned  excavation.

Hazard  Cause

If unclear with the finding of services after  reaching the 2m limit, conduct further  detection to determine the presence of any  services below.

Segar (ES Site Supervisor) Segar (ES Site Supervisor) Segar (ES Site Supervisor)

Segar (ES Site Supervisor) Hari (ES Engineer)

Leonard Kok/ Tan WC

‐ ‐ ‐

‐ ‐

•

• • •

• •

‐ ‐ ‐ ‐ ‐

Thorough study of utilities drawings Cable detections by qualified LCDW Provide clear utilities marking on site Provide A3 size drawing of utility plan Apply permit to dig and implement “checklist  for working near utility” Barricade work area while trenching Contact relevant utility agency for any  presence of unidentified utility Always treat utility as `live’ if encountered Only manual digging allowed for trial trench Full time supervision during trial trench 

• • • • •

Tan WC LCDW Segar (ES Site Supervisor) Segar (ES Site Supervisor) Segar (ES Site Supervisor)

Action Owner

Mitigation Measure

Drain Excavation Risks and Mitigation Measures

Provide rigid barricade and warning signage. Provide proper access. Provide toe board. Provide adequate lighting if necessary. Never store material within 1 m from  excavation edge. Provide proper shoring (in this case sheet  pile) Never allow machineries to park close to  excavation trench.

• • • • • •

Excavation collapse

Poor shoring

Missing fall  protection provision

•

Put up extra support for the pine tree. Brief workers and excavator operator to be  aware of the hazard.

• •

Workers hit  by fallen pine  tree

Damaged  roots

Design and construct strutting work to  prevent soil movement. Pre‐con survey on potential infrastructure /  house.

Sub‐standard  • soil restrain  temporary  • work

Soil  movement  affecting existing  infrastructure

Mitigation Measure

Hazard  Cause

Hazard 

Excavation  Worker /  work material fall  into  excavation.

Activity

Drain Excavation Risks and Mitigation Measures

‐

‐

‐ ‐ ‐ ‐ ‐

Segar (ES Site Supervisor)

Segar (ES Site Supervisor)

Segar (ES Site Supervisor) Segar (ES Site Supervisor) Segar (ES Site Supervisor) Segar (ES Site Supervisor) Segar (ES Site Supervisor)

Peter (JV Superintendent) Segar (ES Site Supervisor)

Erin Rosli (SPRO)

‐

‐ ‐

Jessica (JV Engineer)

‐

Action Owner

Provide support for the pine tree

GI pipes

Pine tree

I beam

Drain Excavation Risks and Mitigation Measures

Ingress/ egress area to be covered with steel plate

Excavation  work

Activity

Close  proximity to  existing canal

Soft ground

Failure to  guide  machineries  movement

Stability of  ground  foundation

Over travel

Excavator  topple

Grabber not  stuck / struck  at bracing

Hazard  Cause

Hazard 

•

•

• • •

Design excavator access COS for access Inspection ground stability after adverse  weather condition Signaler man to guide excavator grabber out of  bracing JV staff to perform standing supervision during  drainage diversion work.

Mitigation Measure

Drain Excavation Risks and Mitigation Measures

‐ ‐

‐ ‐ ‐

Segar (ES Site Supervisor) Jessica (JV Engineer)

Jessica (JV Engineer) Jessica (JV Engineer) Killi (JV Lift Engineer)

Action Owner

Excavation  work

Activity

Uneven  ground

Negligence of  operator

Constraint of  work zone 

Hazard  Cause

Moving steel  plate in  congested  access

Collision of  machinery and  Failure to  site people. guide  machineries  movement

Hazard 

•

•

• • •

•

•

• Ensure work zone is organized with good housekeeping. Proper barricade and demarcation of work  zone to prevent unauthorized entry Establish good communication at all times  between operator and signalman Used of tag line to control swaying of load. Provision of steel plate for machinery Provision of signalman and traffic controller to  guide machinery movement Provide exclusion zone to control movement  of excavator. Define proper access for machines and man.

Mitigation Measure

Drain Excavation Risks and Mitigation Measures

‐ ‐ ‐ ‐

‐

‐

‐

Segar (ES Site Supervisor) Segar (ES Site Supervisor) Segar (ES Site Supervisor) Segar (ES Site Supervisor)

Segar (ES Site Supervisor)

Segar (ES Site Supervisor)

Segar (ES Site Supervisor)

Action Owner

Provide exclusion zone and banksman to prevent  unauthorised entry.

Drain Excavation Risks and Mitigation Measures

Excavation  work

Activity

Loose soil  between  sheet pile  drop off.

Hazard  Cause

Collapse of  loose soil suck  between sheet  Excavator  pile bucket not  able to reach  pocket of  sheet pile.

Hazard 

•

• •

Drain

Excavate not more than 1.2 m deep at one go. Workers to crowbar stuck soil between sheet  pile. Never send workers into excavation without  removing all loose soil between sheet piles.

Mitigation Measure

Drain Excavation Risks and Mitigation Measures

‐ ‐

Segar (ES Site Supervisor) Jessica (JV Engineer)

Action Owner

Excavation  works

Activity

Bentonite  over flow

•

Sheet pile too  • near guide  wall •

Provide adequate bund wall to contain  bentonite. Close monitoring of bentonite flow from plant  side. Deploy watch man throughout the period of  de‐sanding.

‐ ‐

‐ ‐ ‐

Exisiting drain to be clear regularly. Ensure ECM is functioning well. Provide sufficient manpower to maintain silt  fence. No stock pile on site. Cover any residue spoil.

• • •

Bentonite spill  into drain

Heavy rain (Flash flood)

Flooding or  clogging of  existing drain

Segar (ES Site Supervisor) Jessica (JV Engineer)

Guna (LV ECO) Segar (ES Site Supervisor) Jessica (JV Engineer)

Segar (ES Site Supervisor)

‐

Carryout drain excavation during day time. Proper maintenance of excavator. Provide noise barrier to mitigate noise.

• • •

• •

Poor  scheduling of  work. Poor  maintenance  of excavator.

Noise level is  above  acceptable  level

Action Owner

Mitigation Measure

Surface run‐ offs entering   drain

Hazard  Cause

Hazard 

Drain Excavation Risks and Mitigation Measures

Portable treatment plant commissioned to ensure silty  water are properly treated prior discharge into public  drain.

Drain Excavation Risks and Mitigation Measures

Sufficient manpower  deployed to ensure  silt are properly  maintain.

THANK YOU

Missing Risk: • Moving the steel plates for excavator access  Constrain site • Define proper access for machineries and workmen. • Presentation and MS not in line. • Include calculation e.g. track seating on both side of sheet pipe. • MS for strut is not approved yet (comment given in Oct16). • Bentonite may spill into drain (Sheet pile very near to guide wall). • Standing supervision by JV staff.

Comment by LTA

drain excavation.

2) All site personnel should be fully informed and clear with the work process concerning 

and the mitigation measures to be adopted.

1) To identify the potential risk hazards concerning lifting rebar  cage activities at Entrance B 

Objectives of this workshop (no.9):

Hazard 

lifting work Crane collapse

Activity

Incompetent operator

Poor crane  footage

Over load

Hazard  Cause

If unclear with the finding of services after  reaching the 2m limit, conduct further  detection to determine the presence of any  services below.

•

•

•

‐

Implement lift plan and PTW system for Lifting Use only competent lifting personnel Crane access must be design by PE. Crane access must be certify before usage. All load must be identified before lifting. Adopt 3X3 lifting principle. Always observe max. load radius to avoid  overloading. Provide exclusion zone and warning sign to  warn off unauthorised workman. Always reinspect crane access after increment  weather

• • • • • • •

Leonard Kok/ Tan WC

Segar (ES Site Supervisor)

Action Owner

Mitigation Measure

Drain Excavation Risks and Mitigation Measures

Lifting rebar cage in congested work area

Provide rigid barricade and warning signage. Provide proper access. Provide toe board. Provide adequate lighting if necessary. Never store material within 1 m from  excavation edge. Provide proper shoring (in this case sheet  pile) Never allow machineries to park close to  excavation trench.

• • • • • •

Excavation collapse

Poor shoring

Missing fall  protection provision

•

Put up extra support for the pine tree. Brief workers and excavator operator to be  aware of the hazard.

• •

Workers hit  by fallen pine  tree

Damaged  roots

Design and construct strutting work to  prevent soil movement. Pre‐con survey on potential infrastructure /  house.

Sub‐standard  • soil restrain  temporary  • work

Soil  movement  affecting existing  infrastructure

Mitigation Measure

Hazard  Cause

Hazard 

Excavation  Worker /  work material fall  into  excavation.

Activity

Drain Excavation Risks and Mitigation Measures

‐

‐

‐ ‐ ‐ ‐ ‐

Segar (ES Site Supervisor)

Segar (ES Site Supervisor)

Segar (ES Site Supervisor) Segar (ES Site Supervisor) Segar (ES Site Supervisor) Segar (ES Site Supervisor) Segar (ES Site Supervisor)

Peter (JV Superintendent) Segar (ES Site Supervisor)

Erin Rosli (SPRO)

‐

‐ ‐

Jessica (JV Engineer)

‐

Action Owner

Provide support for the pine tree

GI pipes

Pine tree

I beam

Drain Excavation Risks and Mitigation Measures

Ingress/ egress area to be covered with steel plate

Excavation  work

Activity

Close  proximity to  existing canal

Soft ground

Failure to  guide  machineries  movement

Stability of  ground  foundation

Over travel

Excavator  topple

Grabber not  stuck / struck  at bracing

Hazard  Cause

Hazard 

•

•

• • •

Design excavator access COS for access Inspection ground stability after adverse  weather condition Signaler man to guide excavator grabber out of  bracing JV staff to perform standing supervision during  drainage diversion work.

Mitigation Measure

Drain Excavation Risks and Mitigation Measures

‐ ‐

‐ ‐ ‐

Segar (ES Site Supervisor) Jessica (JV Engineer)

Jessica (JV Engineer) Jessica (JV Engineer) Killi (JV Lift Engineer)

Action Owner

Excavation  work

Activity

Uneven  ground

Negligence of  operator

Constraint of  work zone 

Hazard  Cause

Moving steel  plate in  congested  access

Collision of  machinery and  Failure to  site people. guide  machineries  movement

Hazard 

•

•

• • •

•

•

• Ensure work zone is organized with good housekeeping. Proper barricade and demarcation of work  zone to prevent unauthorized entry Establish good communication at all times  between operator and signalman Used of tag line to control swaying of load. Provision of steel plate for machinery Provision of signalman and traffic controller to  guide machinery movement Provide exclusion zone to control movement  of excavator. Define proper access for machines and man.

Mitigation Measure

Drain Excavation Risks and Mitigation Measures

Segar (ES Site Supervisor)

Segar (ES Site Supervisor)

‐ ‐

Segar (ES Site Supervisor) Segar (ES Site Supervisor) Segar (ES Site Supervisor) Segar (ES Site Supervisor)

Segar (ES Site Supervisor)

Segar (ES Site Supervisor)

Segar (ES Site Supervisor)

‐ ‐ ‐ ‐

‐

‐

‐

Action Owner

Provide exclusion zone and banksman to prevent  unauthorised entry.

Drain Excavation Risks and Mitigation Measures

Excavation  work

Activity

Loose soil  between  sheet pile  drop off.

Hazard  Cause

Collapse of  loose soil suck  between sheet  Excavator  pile bucket not  able to reach  pocket of  sheet pile.

Hazard 

•

• •

Drain

Excavate not more than 1.2 m deep at one go. Workers to crowbar stuck soil between sheet  pile. Never send workers into excavation without  removing all loose soil between sheet piles.

Mitigation Measure

Drain Excavation Risks and Mitigation Measures

‐ ‐

Segar (ES Site Supervisor) Jessica (JV Engineer)

Action Owner

Excavation  works

Activity

Bentonite  over flow

•

Sheet pile too  • near guide  wall •

Provide adequate bund wall to contain  bentonite. Close monitoring of bentonite flow from plant  side. Deploy watch man throughout the period of  de‐sanding.

‐ ‐

‐ ‐ ‐

Exisiting drain to be clear regularly. Ensure ECM is functioning well. Provide sufficient manpower to maintain silt  fence. No stock pile on site. Cover any residue spoil.

• • •

Bentonite spill  into drain

Heavy rain (Flash flood)

Flooding or  clogging of  existing drain

Segar (ES Site Supervisor) Jessica (JV Engineer)

Guna (LV ECO) Segar (ES Site Supervisor) Jessica (JV Engineer)

Segar (ES Site Supervisor)

‐

Carryout drain excavation during day time. Proper maintenance of excavator. Provide noise barrier to mitigate noise.

• • •

• •

Poor  scheduling of  work. Poor  maintenance  of excavator.

Noise level is  above  acceptable  level

Action Owner

Mitigation Measure

Surface run‐ offs entering   drain

Hazard  Cause

Hazard 

Drain Excavation Risks and Mitigation Measures

Portable treatment plant commissioned to ensure silty  water are properly treated prior discharge into public  drain.

Drain Excavation Risks and Mitigation Measures

Sufficient manpower  deployed to ensure  silt are properly  maintain.

THANK YOU

Missing Risk: • Moving the steel plates for excavator access  Constrain site • Define proper access for machineries and workmen. • Presentation and MS not in line. • Include calculation e.g. track seating on both side of sheet pipe. • MS for strut is not approved yet (comment given in Oct16). • Bentonite may spill into drain (Sheet pile very near to guide wall). • Standing supervision by JV staff.

Comment by LTA

activity.

2) All site personnel should be fully informed and clear with the work process concerning this 

and the mitigation measures to be adopted.

1) To identify the potential risk hazards concerning lifting bulky load activities at Entrance B 

Objectives of this workshop (no.10):

T309 Site over view

Lifting Activities Risks and Mitigation Measures

Lifting rebar cage in congested work area

Due to the tight area, occasional lifting operation in  entrance B involve the management of load swinging over  hoarding supervised by our fully competent lifting team.

Lifting rebar cage in congested work area

lifting work

Crane  collapse

Activity Hazard 

Incompetent operator

Poor crane footage

Over load

Hazard Cause

• •

•

•

• • •

‐ ‐

‐

‐

‐ ‐ ‐

Thiah (HSL Engineer) Killi (JV Lift Engineer)

Shajahan (HSL Lifting Supervisor)

Shajahan (HSL Lifting Supervisor)

Shajahan (HSL Lifting Supervisor) Shajahan (HSL Lifting Supervisor) Shajahan (HSL Lifting Supervisor)

Omar (HSL Safety Coordinator) Desi (JV Engineer) Desi (JV Engineer) Desi (JV Engineer) Killi (JV Lift Engineer)

‐ ‐ ‐ ‐ ‐

• • • • • Implement lift plan and PTW system for Lifting Use only competent lifting personnel ‐ VOC Crane access must be design by PE. Crane access must be certify before usage. Always reinspect crane access after adverse  weather All load must be identified before lifting. Adopt 3X3 lifting principle. Always observe max. load radius to avoid  overloading. Provide exclusion zone and warning sign to  warn off unauthorised workman. Ensure no excavation work to be carried out  next to crane access (unless crane access  integrity is designed and calculated to cater for  it). Do not use degraded crane for lifting work. Conduct weekly boom down to ensure  structure integrity of crane.

Action Owner

Mitigation Measure

Lifting Activities Risks and Mitigation Measures

lifting  work

Load hit on  crane e.g.  wind screen

Hit by fallen  load

Activity Hazard 

‐ ‐ ‐

Inadequate  load radius

Congested work area ‐ ‐

Incompetent  lifting team ‐

‐

Lift plan got to take min load radius into  consideration based on the physical load size. Adopt 3X3 lifting principle Competent rigger Proper communication between lift team  members. Deploy additional measures for lift activities  in congested  area. Do not jerk or swing boom too fast. Provide sufficient tag lines

‐ ‐

‐

‐ ‐ ‐

‐

Ng Bok Soon (HSL Crane Operator) Shajahan (HSL LS)

Shajahan (HSL LS)

Shajahan (HSL LS) Junaet (HSL R/S) Shajahan (HSL LS)

Thiah (HSL Engineer)

Killi (JV Lift Eng) Junaet (HSL R/S) Omar (HSL Safety Coordinator) Shajahan (HSL LS) Shajahan (HSL LS) Ng Bok Soon (HSL Crane Operator) Shajahan (HSL LS) Shajahan (HSL LS)

‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐

‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐

Monthly colour code system No over loading Competent rigger Proper storage of LG Proper maintenance of LG No suspended over workmen at all times. Provide exclusion zone and warning signage. Identify approved lifting points of rebar cage.

Action Owner

Mitigation Measure

Bulky load

Suspended load over  people

LG failure

Hazard  Cause

Lifting Activities Risks and Mitigation Measures

Diverted hoarding

Lifting Activities Risks and Mitigation Measures

Existing hoarding alignment

Lifting Activities Risks and Mitigation Measures

Traffic control when hoisting material above hoarding

Hazard 

Workmen  lifting work being crushed  by moving  cranes

Activity

Failure to  control traffic

Blind spot

Hazard  Cause

• •

Desi (JV Engineer) Desi (JV Engineer) Killi (JV Lift Engineer) Segar (ES Site Supervisor) Desi (JV Engineer)

‐ ‐ ‐ ‐ ‐

• • Provide exclusion zone and warning signs. Ensure rigger/signaller are deployed to  prevent unauthorised entry into lift zone. Never place tools/material on lifting machines. Avoid working in congested work area.

Action Owner

Mitigation Measure

Lifting Activities Risks and Mitigation Measures

THANK YOU

activity.

2) All site personnel should be fully informed and clear with the work process concerning this 

the mitigation measures to be adopted.

1) To identify the potential risk hazards concerning Noise Barrier erection at Elliod Walk and 

Objectives of this workshop (no.11):

Elliod Walk

Elliod Walk

Existing noise barriers

Noise  barrier  Erection

Activity

MEWP topple

Hit by fallen  object

Fall from  height

Risk

Over loading  of MEWP

Poor footage

Failure to  provide  control

•

•

Familiarisation briefing prior appointment.

Licensed MEWP operator.

Provide adequate work platform.

Provide proper access.

• •

Establish PTW‐Height system.

•

‐

‐

‐

‐

‐

Richee Supervisor

Richee Supervisor

Richee Supervisor

Richee Supervisor

JV Safety Dept.

Richee engineer 

‐

•

Failure to  provide fall  protection  provision Provision of Fall Protection Plan.

Action Owner

Mitigation Measure

Hazard  Cause

Noise Barrier Erection – Elliod Walk

Ensure proper MEWP footage

Noise Barrier Erection – Elliod Walk

Max. 2 person in MEWP bucket

Noise  barrier  Erection

Activity

MEWP topple

Hit by fallen  object

Fall from  height

Risk

Over loading  of MEWP

Poor footage

Failure to  provide  control

Firm and compacted ground for MEWP access. Provide adequate exclusion zone and signage. Provide banksman to ensure no authorised 

• • •

entry in to work zone.

Max. weight 120kg.

Limit max. 2 person on MEWP.

netting to contain material.

•

•

•

Failure to  provide fall  protection  provision Enveloped MEWP work platform with scaffold 

Mitigation Measure

Hazard  Cause

Noise Barrier Erection – Elliod Walk

‐

‐

‐

‐

‐

‐

Richee Supervisor

Richee Supervisor

JV Engineer

MEWP Operator

Richee Supervisor

Richee Supervisor

Action Owner

Lifting work

Activity

Crane hit surrounding structures, e.g. silo

Crane Toppling

Risk 

•Load hit onto crane

•Instability of working platform

•Failure of loose material equipment/ rebar cages

Hazard Cause

Noise Barrier Erection – Elliod Walk

‐

Richee LS

Richee SC

‐ • Look into min load radius when hoisting bulky items e.g. rebar cage. •Only R/S can give signal. Trade supervisor cannot involved in lifting work.

Richee R/S

Richee LS

Richee CO Richee LS

‐

‐

‐ ‐

•Signaler to communicate with crane operator

•Safety zone established

•Material shall be stacked safely and within stacking limit and load

•Low speed in lifting and lowering

JV Engineer

JV LE

‐

•Approved lifting plan, reviewed by LE and approved by PM

‐

Richee LS

‐

•Lift load by 300mm, stabilized for 3 seconds.

•Lifting points to be identified and approved

Action Owner

Mitigation Measure

Provide exclusion zone and banksman to prevent  unauthorised entry.

Noise Barrier Erection – Elliod Walk

Include min load radius in load chart

Lifting work

Activity

Crane hit surrounding structures, e.g. silo

•Banksmen to guide crawler crane movement, ensuring no tracking over drain, trench or uneven ground.

Richee R/S

Richee LS

‐ ‐

JV PM

Richee supervisor

‐

‐

Richee supervisor

‐

•Put in place the lifting permit system and display the relevant details on site.

•Instability of working platform •Ensure no overloading of crane •Failure of loose material •Signaler to communicate with crane equipment/ rebar cages operator •Lack of communication •Approved lifting plan, reviewed by LE and approved by PM •Inadequate supervision and control •Lifting operation supervised by lifting supervisor

JV Superintendent

‐

•Provide adequate hardstanding /firm working platform

crane Toppling

Action Owner

Mitigation Measure

Hazard Cause

Risk 

Noise Barrier Erection – Elliod Walk

Welding work with fire screen, extinguisher and fire  watchman standby.

Noise Barrier Erection – Elliod Walk

No welding during wet weather.

THANK YOU

By: Tommy Lee/ Peter Nugent

activity.

Date: 26 Apr 17

2) All site personnel should be fully informed and clear with the work process concerning this 

and the mitigation measures to be adopted.

1) To identify the potential risk hazards concerning Noise Barrier erection at Laguna Park 

Objectives of this workshop (no.12):

Traffic Diversion Stage 1C

Traffic Diversion Stage 1C

Traffic Diversion Stage 1C

Traffic Diversion Stage 1C

Traffic Diversion Stage 1C

Traffic Diversion Stage 1C

Utility Bridge– Siglap link

Temporary Drain Diversion

TD1C

Noise  barrier  Erection

Activity

MEWP topple

Hit by fallen  object

Fall from  height

Risk

Over loading  of MEWP

Poor footage

•

•

•

Familiarisation briefing prior appointment.

Licensed MEWP operator.

Provide adequate work platform.

Provide proper access.

•

‐

‐

Sayeed Hassan (Richee LS)

Sayeed Hassan (Richee LS)

Sayeed Hassan (Richee LS)

Sayeed Hassan (Richee LS)

‐

Establish PTW‐Height system.

•

‐

JV Safety Dept.

‐

Failure to  provide  control

Sayeed Hassan (Richee LS)

‐

•

Failure to  provide fall  protection  provision Provision of Fall Protection Plan.

Action Owner

Mitigation Measure

Hazard  Cause

Noise Barrier Erection – Laguna Park

Ensure proper MEWP footage

Noise Barrier Erection – Laguna Park

Max. 2 person in MEWP bucket

Noise  barrier  Erection

Activity

MEWP topple

Hit by fallen  object

Fall from  height

Risk

Over loading  of MEWP

Poor footage

Failure to  provide  control

Firm and compacted ground for MEWP access. Provide adequate exclusion zone and signage. Provide banksman to ensure no authorised 

• • •

entry in to work zone.

Max. weight 120kg.

Limit max. 2 person on MEWP.

netting to contain material.

•

•

•

Failure to  provide fall  protection  provision Enveloped MEWP work platform with scaffold 

Mitigation Measure

Hazard  Cause

Noise Barrier Erection – Laguna Park

‐

‐

‐

‐

‐

‐

Sayeed Hassan (Richee LS)

Sayeed Hassan (Richee LS)

Jay Cel Galura (JV Engineer)

Atique/ Biswas (MEWP Operator)

Sayeed Hassan (Richee LS)

Sayeed Hassan (Richee LS)

Action Owner

Lifting work

Crane hit surrounding structures, e.g. silo

Crane Toppling

•Material shall be stacked safely and within stacking limit and load

•Low speed in lifting and lowering

•Lifting points to be identified and approved

•Approved lifting plan, reviewed by LE and approved by PM

‐

•Lift load by 300mm, stabilized for 3 seconds.

‐

‐

•Only R/S can give signal. Trade supervisor cannot involved in lifting work.

‐

• Look into min load radius when hoisting bulky items e.g. rebar cage.

operator

‐

‐

Sayeed Hassan (Richee LS)

Sayeed Hassan (Richee LS) Sayeed Hassan (Richee LS) Sayeed Hassan (Richee LS) Sayeed Hassan (Richee LS) Sayeed Hassan (Richee LS)

Jay Cel (JV Engineer)

‐

‐

Killi (JV LE)

‐

Sayeed Hassan (Richee LS)

Action Owner

Mitigation Measure

•Instability of working platform •Safety zone established •Load hit onto crane •Signaler to communicate with crane

•Failure of loose material equipment/ rebar cages

Noise Barrier Erection – Laguna Park Activity Risk  Hazard Cause

Provide exclusion zone and banksman to prevent  unauthorised entry.

Noise Barrier Erection – Laguna Park

Include min load radius in load chart

Lifting work

Activity

Crane hit surrounding structures, e.g. silo

•Instability of working platform •Ensure no overloading of crane •Failure of loose material •Signaler to communicate with crane equipment/ rebar cages operator •Lack of communication •Approved lifting plan, reviewed by LE and approved by PM •Inadequate supervision and control •Lifting operation supervised by lifting supervisor

crane Toppling

•Banksmen to guide crawler crane movement, ensuring no tracking over drain, trench or uneven ground.

•Put in place the lifting permit system and display the relevant details on site.

‐

•Provide adequate hardstanding /firm working platform

‐

Sayeed Hassan  (Richee LS)

Sayeed Hassan  (Richee LS) Frank Yi (JV PM) Sayeed Hassan  (Richee LS)

‐ ‐ ‐

Sayeed Hassan  (Richee LS)

‐

Peter Nugent (JV Superintendent)

Action Owner

Mitigation Measure

Hazard Cause

Risk 

Noise Barrier Erection – Laguna Park

Welding work with fire screen, extinguisher and fire  watchman standby.

Noise Barrier Erection – Laguna Park

No welding during wet weather.

THANK YOU

Minutes Title: Risk Register Workshop No 12 Date: 26 Apr 2017 Time: 10.00am-11.00am Held at: LTA level 2 meeting room

Chaired by: Tommy Lee/ Peter Nugent Minuted by: Tommy Lee Distribution date: 4 May 17

Attendees list See attached

Apologies list

Page 1 of 3

Minutes ITEM

MATTERS DISCUSSED

1.0

Introduction

ACTION

Risk Workshop will be on Noise Barrier installation at Laguna Park held on 26 Apr 2017 was submitted. This is the no. 12 workshop held.

Info

The complete flow of the process will be demonstrated via a short slide presentation The project superintendent will provide the necessary information required to mitigate risks on Noise Barrier installation.

2.0

Slide presentation on Noise Barrier performed at Laguna Park Area

Peter

2.1

LTA informed JHZH that Lighting shall be sufficient for the street after installation of Noise Barrier.

JHZH

2.2

QPS informed JHZH when tighening the bolt, JHZH shall inform RTO.

JHZH

2.3

QPS informed that the spacing of the support between the noise barrier shall be checked and reinforced.

JHZH

2.4

QPS informed that once inspected, no changes shall be made.

JHZH

2.5

LTA informed that MEWP specification shall be attached in the permit. Safety hardness anchorage point must be identified and all approved personnel to operate the MEWP shall be displayed clearly.

JHZH

2.6

LTA informed that flashback arrester shall be available with the hot works equipment.

JHZH

2.7

LTA informed that utilities cable shall be boxed-up/ encased to prevent damage.

JHZH

2.8

JHZH commented that CCTV location has been identified and proposed.

Info

Page 2 of 3

Minutes ITEM

MATTERS DISCUSSED

3.0

Any Other Matters:

ACTION

The next workshop shall cover TD1 connection to canal works at Entrance A or L-shap D-wall panel installation between Entrance B and C.

4.0

INFO

Next Workshop The next workshop will be scheduled on 4 May 17 @ 10am

Page 3 of 3

All / Info

Drainage Diversion.

2) All site personnel should be fully informed and clear with the work process concerning 

and the mitigation measures to be adopted.

1) To identify the potential risk hazards concerning Drainage Diversion TD1 at Entrance A 

Objectives of this workshop (no.13):

Drainage Diversion TD1 details

Drain Length: 77.5m (37.3m+ 40.2m) Width: 1.5m Depth: Max. 3.15m

Start: 10 Apr 17 Finish: 18 May 17

Drainage Diversion TD1 details

Scope of works 1. Underground Utility detection/ trial trenching 2. Sheetpiling 3. Installation of working platform 4. Excavation, Installation of walers and struts and access 5. Subgrade compaction 6. Concrete pouring and casting at base 7. Laying Precast Channel and pipe installation and hardcore 8. Sandbag installation at drain/canal connection  9. Water Pump installation upstream to downstream 10. Sheetpile connection to existing drain 11. Backfill and demolish existing drain

Excavation TD1 details

Drainage Diversion TD1 details

Damaged to :

Excavation  work

Water pipe. Power grid  cables. Telecom  cables. High tension  cables.

Hazard 

Activity

Failure to  conduct  detection  test.

Insufficient  marking on  site.

Unplanned  excavation.

Hazard  Cause

If unclear with the finding of services after  reaching the 2m limit, conduct further  detection to determine the presence of any  services below.

•

• • •

• •

Thorough study of utilities drawings Cable detections by qualified LCDW Provide clear utilities marking on site Provide A3 size drawing of utility plan Apply permit to dig and implement “checklist  for working near utility” Barricade work area while trenching Contact relevant utility agency for any  presence of unidentified utility Always treat utility as `live’ if encountered Only manual digging allowed for trial trench Full time supervision during trial trench 

• • • • •

Mitigation Measure

Drain Excavation Risks and Mitigation Measures

Tan WC LCDW Segar (ES Site Supervisor) Hari (ES Engineer)

Leonard Kok/ Tan WC

‐ ‐ ‐ ‐

Action Owner

Provide rigid barricade and warning signage. Provide proper access. Provide toe board. Provide adequate lighting if necessary. Never store material within 1 m from  excavation edge. Provide proper shoring (in this case sheet  pile) Never allow machineries to park close to  excavation trench.

• • • • • •

Excavation collapse

Poor shoring

Missing fall  protection provision

•

Put up extra support for the pine tree. Brief workers and excavator operator to be  aware of the hazard.

• •

Workers hit  by fallen pine  tree

Damaged  roots

Design and construct strutting work to  prevent soil movement. Pre‐con survey on potential infrastructure /  house.

Sub‐standard  • soil restrain  temporary  • work

Soil  movement  affecting existing  infrastructure

Mitigation Measure

Hazard  Cause

Hazard 

Excavation  Worker /  work material fall  into  excavation.

Activity

Drain Excavation Risks and Mitigation Measures

‐ ‐

‐ ‐

‐ ‐

‐ ‐

Segar (ES Site Supervisor) Jessica (JV Engineer)

Segar (ES Site Supervisor) Jessica (JV Engineer)

Segar (ES Site Supervisor) Jessica (JV Engineer)

Jessica (JV Engineer) Erin Rosli (SPRO)

Action Owner

Support for the pine tree

GI pipes

Pine tree

I beam

Drain Excavation Risks and Mitigation Measures

Excavation  work

Activity

Establish good communication at all times  between operator and signalman Used of tag line to control swaying of load. Provision of steel plate for machinery Provision of signalman and traffic controller to  guide machinery movement Provide exclusion zone to control movement  of excavator.

•

• •

Negligence of  operator

Ensure work zone is organized with good housekeeping. Proper barricade and demarcation of work  zone to prevent unauthorized entry

•

Constraint of  work zone 

Failure to  guide  machineries  movement •

•

•

Mitigation Measure

Hazard  Cause

Collision of  machinery and  Uneven  site people. ground

Hazard 

Drain Excavation Risks and Mitigation Measures

‐ ‐

Segar (ES Site Supervisor) Jessica (JV Engineer)

Action Owner

Provide exclusion zone and banksman to prevent  unauthorised entry.

Drain Excavation Risks and Mitigation Measures

Excavation  works

Activity

Surface run‐ offs entering   drain

Heavy rain (Flash flood)

Poor  scheduling of  work. Poor  maintenance  of excavator.

Noise level is  above  acceptable  level

Flooding or  clogging of  existing drain

Hazard  Cause

Hazard 

• •

• • •

Existing drain to be clear regularly. Ensure ECM is functioning well. Provide sufficient manpower to maintain silt  fence. No stock pile on site. Cover any residue spoil.

‐ ‐ ‐

Guna (LV ECO) Segar (ES Site Supervisor) Jessica (JV Engineer)

Segar (ES Site Supervisor)

‐

• • • Carryout drain excavation during day time. Proper maintenance of excavator. Provide noise barrier to mitigate noise.

Action Owner

Mitigation Measure

Drain Excavation Risks and Mitigation Measures

Sufficient manpower deployed to  ensure silt are properly maintain.

Drain Excavation Risks and Mitigation Measures

THANK YOU

Minutes Title: Risk Register Workshop No 13 Date: 4 May 2017 Time: 10.00am-11.00am Held at: LTA level 2 meeting room

Chaired by: Tommy Lee/ Peter Nugent Minuted by: Tommy Lee Distribution date: 12 May 17

Attendees list See attached

Apologies list

Page 1 of 3

Minutes ITEM

MATTERS DISCUSSED

1.0

Introduction

ACTION

Risk Workshop will be on TD1 canal works at Entrance A held on 4 May 2017 was submitted. This is the no. 13 workshop held.

Info

The complete flow of the process will be demonstrated via a short slide presentation The project superintendent will provide the necessary information required to mitigate risks on TD1 canal works.

2.0

2.1

2.2

2.3

Slide presentation on TD1 canal works performed at Entrance A LTA informed JHZH that any close out drain needs to inform LTA project team as it may lead to environmental issues such as mosquito breeding. LTA informed that there should be a standard procedure to evacuate personnel who have accessed into drain.

JHZH informed that the pine tree at Ent A shall be inspected and maintained during the construction phase.

2.4

Peter

JHZH

JHZH

JHZH

JHZH LTA informed to check any impact on D-wall when clearing out the old canal.

2.5

JHZH JHZH informed that only two types of barriers are to be within the site. The fixed and movable type. Water barriers are to be only used for road works.

2.6

2.7

JHZH informed that permanent ECM is in use during construction.

JHZH commented that CCTV location has been identified and proposed.

Page 2 of 3

JHZH

JHZH

Minutes ITEM

MATTERS DISCUSSED

3.0

Any Other Matters:

ACTION

The next workshop shall cover TD1 connection to canal works at Entrance A during 3 months look ahead programme.

4.0

INFO

Next Workshop The next workshop will be scheduled on 19 May 17 @ 10am. It will be a 3 month look ahead programme.

Page 3 of 3

All / Info

such work activities.

2) All site personnel should be fully informed and clear with the work process concerning 

and the mitigation measures to be adopted.

1) To identify the potential risk hazards concerning mob and demob of heavy machineries 

Objectives of this workshop (14):

Mob / demo  heavy  machineries 

Activity

Workers hit by  topple  machineries

Machines topple

Hazard 

Poor  supervision

Poor planning

Hazard  Cause

Ensure proper footage Mob/demob on clear weather condition

‐ ‐

Provide exclusion zone and banksman Only relevant staff are allowed to be involved in mob/demob Risk assessment must be approved prior activity Never mob/demob at congested work area Always ensure height limit is <4.5m Operator deployed must be appointed and licensed (if applicable) Machines must be approved by LTA prior mobilisation New machines to comply with LTA “Approval Procedure for new  machine”.

‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐

Never mob/demob during wet weather condition

Angle of ramp within machine manufacturer recommendation

‐

‐

Ramp of trailer must be equal or wider than machine crawler belt.

‐

trailers is used for mob / demob

JV LE (Killi) Sub con supervisor

‐ ‐

Sub con supervisor JV LE (Killi) JV super. (Peter) JV super. (Peter) Sub con supervisor Sub con supervisor JV LE (Killi) JV LE (Killi)

‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐

Sub con supervisor

JV LE (Killi)

‐

‐

JV LE (Killi)

‐

JV LE (Killi)

‐

‐

Obtained machineries technical information to ensure fix for purpose 

Action Owner

Mitigation Measure

Mob / demobilisation Risk and measures

New machines – Seek approval by submission of relevant  document and requirement prior mobilisation.

Mob / demobilisation Risk and measures

Never mob/demob at congested work area

Avoid mob/demob on night shift

Mob/demob on clear and dry weather condition

Ground preparation to ensure stable footage for mobilisation

Mob / demobilisation Risk and measures

• Turning radius of trailers etc

• Length and height of trailers

• Capacity of trailers

trailers <4.5m.

• Total height of loaded machines on 

• Weight of machine

• Width of machine

• Width of machine track

FOS)

• Max angle of machines travel (giving 

Obtain technical information of  machineries such as;

Mob / demobilisation Risk and measures

conditions etc.

• Machineries in good working 

submitted and accepted.

• All required documentation 

• Approval of machines by LTA / JV

accordance with design

• Area to park and steel plate layout 

machineries (giving FOS)

• Ground bearing for heavy 

Obtain other information such as;

Provide exclusion zone for mob‐demob  activity

Conduct pre‐check prior mob/demob of  machines

Mob / demobilisation Risk and measures

Alcohol check on operator involved in mob/demob  prior operation

Traffic control in place to ensure  smooth transition into worksite

Only relevant personnel are allowed to  get involved in mob/demob operation

Mob / demobilisation Risk and measures

Conduct briefing to relevant personnel involved in mob/demob activity

End

activity.

2) All site personnel should be fully informed and clear with the work process concerning this 

mitigation measures to be adopted.

1) To identify the potential risk hazards concerning Walkway erection at Elliot Walk and the 

Objectives of this workshop (no.15):

Location of walkway Erection ‐ Elliot Walk

Erected walkway: Length: 80m Width: 1.5m

Elliot Walk

Workers work platform

Walk way  Erection

Activity

Slip trip and  fall

Hit by fallen  object

Fall into drain

Risk

Poor footage

Mishandling  of I beam

Failure to  provide  proper access

Hazard  Cause

Noise Barrier Erection – Elliot Walk

•

Ensure proper barricades are put up. Provide adequate toe board.

•

Provide proper work access for erectors.

• •

Provide anti skid platform.

Sreedam (LE Supervisor) Sreedam (LE Supervisor)

•

Sreedam (LE Supervisor)

• •

Sreedam (LE Supervisor)

Sreedam (LE Supervisor)

Sreedam (LE Supervisor)

•

Only qualified welders allowed to carry out welding. •

area.

Storage of materials only at designated storage 

•

•

•

Sreedam (LE Supervisor)

•

• Provide proper walk way – footage over drain

Action Owner

Mitigation Measure

‐ Property             damaged Fire and  ‐ Injury to  explosion public or  workers

Welding  work

Hazard  Cause

Hazard 

Activity

• •

• • • • •

‐ ‐

‐ ‐ ‐ ‐ ‐

Sreedam (LE Supervisor) Sreedam (LE Supervisor)

Sreedam (LE Supervisor) Sreedam (LE Supervisor) Sreedam (LE Supervisor) Sreedam (LE Supervisor) Sreedam (LE Supervisor)

Sreedam (LE Supervisor) Sreedam (LE Supervisor) Sreedam (LE Supervisor) Sreedam (LE Supervisor)

‐ ‐ ‐ ‐

• • • • PPE: Welding face shield, apron and gauntlet Proper housekeeping Method Statements  Apply PTW (e.g. hot works) daily before  commencements of works Daily welding set checklist/ inspection Standby fire extinguishers and fire blankets Reminder in Tool box meeting Certified welders Remove flammable items (timber, canvas etc..  )from welding premises Monthly inspection of welding equipment Apply Safe Work Procedure

Action Owner

Mitigation Measure

Drain wall bracing Risks and Mitigation Measures

Welding work with fire screen, extinguisher and fire  watchman standby.

Walk Way Erection – Elliot Walk

No welding during wet weather.

Manual  Handling

Activity

Load dropped  on foot

Back strain

Risk

Poor footage

Insufficient  manpower

Load too  heavy

Hazard  Cause

Noise Barrier Erection – Elliot Walk

•

• • •

‐

Sreedam (LE Supervisor)

Sreedam (LE Supervisor) Sreedam (LE Supervisor) Sreedam (LE Supervisor) Sreedam (LE Supervisor) Sreedam (LE Supervisor) Sreedam (LE Supervisor) Sreedam (LE Supervisor) Sreedam (LE Supervisor)

‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐

• • • • Position load (I beam) close to the body. Use two hand rather than one hand. Plan your routes. Proper communication if more than one  person are lifting. Introduce proper task rotation. Introduce short and frequent work‐rest cycles. Try using large muscles groups instead of  small. Minimized the number of time the load is  lifted.

Action Owner

Mitigation Measure

• Minimized the number of time the load is lifted.

• Try using large muscles groups instead of small.

• Introduce short and frequent work‐rest cycles.

• Introduce proper task rotation.

• Proper communication if more than one person are lifting.

• Plan your routes.

• Use two hand rather than one hand.

• Position load (I beam) close to the body.

Manual Handing ‐ Risk Control

Noise Barrier Erection – Elliot Walk

Lift load using thigh and calf muscles.   Load maintain close to body.

Ensure firm grip is applied, bend  knees and straighten back.

THANK YOU

activity.

2) All site personnel should be fully informed and clear with the work process concerning this 

measures to be adopted.

1) To identify the potential hazards concerning TD1C construction and the mitigation 

Objectives of this workshop (no.16):

Traffic diversion – 1C

Elliot Walk

Traffic diversion – 1C

Traffic  Diversion

Activity

Poor planning

Hazard Cause

Noise 

Complaints  from  stakeholder

Traffic jam /  congestion

Lack of  coordination

Workers hit by  Lack of  traffic communication

Motorist  confusion

Public  confusion

Risk

Risk mitigation

Traffic diversion – 1C

Apply for lane closure Close lane in accordance with COP Traffic control Put up sufficient advance warning signage

• •

parties on personnel on process of diversion.

Briefing session to be conducted with all relevant 

parties

Organise “work session” to brief all relevant 

LTA

Coordinate closely with relevant authority e.g. 

•

•

•

•

Sufficient and clear  notification signage to 

• motorist – e.g. VMS

Clear and advance notification to all stake holders

•

Mitigation Measure

Jay Cel (JV Site Engineer) Hari (ES Engineer) Jay Cel (JV Site Engineer)

• •

Jay Cel (JV Site Engineer)

• •

Jay Cel (JV Site Engineer)

Jay Cel (JV Site Engineer)

Jay Cel (JV Site Engineer)

Erin (JV SPRO)

•

•

•

•

Action Owner

Traffic  Diversion

Activity

Noise

Complaints  from  stakeholder

Traffic jam /  congestion

Lack of  coordination •

•

Inform NEA about late traffic diversion work 

•

Workers hit by  Lack of  communication traffic

Carry out traffic diversion off peak hours.

•

Poor planning

Motorist  confusion

batons

Traffic controllers to equipped with light 

Ensure workers put on reflective vest.

– Potential noise issue

start

Brief TCP to all relevant person prior work 

Mitigation Measure •

Hazard Cause

Public  confusion

Hazard 

Risk mitigation

Traffic diversion – 1C

•

Hari (ES Engineer)

Mike (JV Safety)

Arron  (JV ECO)

• •

Jay Cel (JV Site Engineer)

Jay Cel (JV Site Engineer)

•

•

Action Owner

Communication ‐ Authority

Traffic diversion – 1C

Notification to eRMA with the help of LTA project team

LTA communication with Main contractors

Communication – LTA / Main Contractors  /Sub contractors

Traffic diversion – 1C

Contractors communication

Main contractors to stake holders

Communication – Stakeholders/residents

Traffic diversion – 1C

Briefing to stakeholders

Presentation to Laguna Park Residents 

Communication – Laguna Park resident

Traffic diversion – 1C

Communication – Motorist 

Traffic diversion – 1C

Information will change accordingly

Traffic Closure

Traffic diversion – 1C

Deployment of APO at strategic location for traffic controls

Traffic Closures ‐ Auxiliary Police Officers

Traffic diversion – 1C

THANK YOU

Minutes Title: Risk Register Workshop No 16 Date: 22 Jun 2017 Time: 10.30am-11.30am Held at: LTA level 2 meeting room

Chaired by: Tommy Lee/ Peter Nugent Minuted by: Tommy Lee Distribution date: 28 Jun 17

Attendees list See attached

Apologies list

Page 1 of 3

Minutes ITEM

MATTERS DISCUSSED

1.0

Introduction

ACTION

Risk Workshop will be on Traffic Diversion 1C on 22 Jun 2017 was submitted. This is the no. 16 workshop held.

Info

The complete flow of the process will be demonstrated via a short slide presentation The project superintendent together with site engineer will provide the necessary information required to mitigate risks on Traffic Diversion 1C works.

2.0

2.1

2.2

2.3

2.4

2.5

2.6

Slide presentation on TD1C performed at Laguna Park

T309P informed that VMS recovery takes long. JHZH said currently we have 12 batteries on standby and the recovery should be manageable. T309P informed that Elliot at East Coast Park shall be notified on the change of footpath by sending out a simplified circular. JHZH informed walkway at the back is in progress. T309P informed that JHZH shall follow up on the implementation that residents use proper footpath. JHZH and subcon will continue to educate the drivers and pedestrians to use designated crossing, footpath and follow road direction. Once pedestrian path close at Ent D, additional signage may be required. T309P informed that the hoarding needs to be properly closed.

T309P informed that emergency reporting must be in place and use of whatsapp to inform.

JHZH informed a separate session on the 20 hours road closure will be presented to LTA addressing each stage of the traffic control zone.

Peter/ Jay Cel JHZH

JHZH

JHZH

JHZH

JHZH

Note

2.7 T309P mentioned some of the risks are not covered, risks on road works, shifting of bus stop, managing live traffic near siglap link, marine parade road and laguna park exit intersection. It will be conducted covering these risks on 6th Jul 17.

Page 2 of 3

JHZH

Minutes ITEM

MATTERS DISCUSSED

3.0

Any Other Matters:

ACTION

The next workshop shall cover utilities services in general.

4.0

INFO

Next Workshop The next workshop will be scheduled on 29 Jun 17 @ 10am. It will be a weekly programme.

Page 3 of 3

All / Info

such work activities.

2) All site personnel should be fully informed and clear with the work process concerning 

and the mitigation measures to be adopted.

1) To identify the potential risk hazards concerning mob and demob of heavy machineries 

Objectives of this workshop (18):

Mob / demo  heavy  machineries 

Activity

Workers hit by  topple  machineries

Machines topple

Hazard 

Poor  supervision

Poor planning

Hazard  Cause

Ensure proper footage Mob/demob on clear weather condition

‐ ‐

Provide exclusion zone and banksman Only relevant staff are allowed to be involved in mob/demob Risk assessment must be approved prior activity Never mob/demob at congested work area Always ensure height limit is <4.5m Operator deployed must be appointed and licensed (if applicable) Machines must be approved by LTA prior mobilisation New machines to comply with LTA “Approval Procedure for new  machine”.

‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐

Never mob/demob during wet weather condition

Angle of ramp within machine manufacturer recommendation

‐

‐

Ramp of trailer must be equal or wider than machine crawler belt.

‐

trailers is used for mob / demob

JV LE (Killi) Sub con supervisor

‐ ‐

Sub con supervisor JV LE (Killi) JV super. (Peter) JV super. (Peter) Sub con supervisor Sub con supervisor JV LE (Killi) JV LE (Killi)

‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐

Sub con supervisor

JV LE (Killi)

‐

‐

JV LE (Killi)

‐

JV LE (Killi)

‐

‐

Obtained machineries technical information to ensure fix for purpose 

Action Owner

Mitigation Measure

Mob / demobilisation Risk and measures

New machines – Seek approval by submission of relevant  document and requirement prior mobilisation.

Mob / demobilisation Risk and measures

Never mob/demob at congested work area

Avoid mob/demob on night shift

Mob/demob on clear and dry weather condition

Ground preparation to ensure stable footage for mobilisation

Mob / demobilisation Risk and measures

• Turning radius of trailers etc

• Length and height of trailers

• Capacity of trailers

trailers <4.5m.

• Total height of loaded machines on 

• Weight of machine

• Width of machine

• Width of machine track

FOS)

• Max angle of machines travel (giving 

Obtain technical information of  machineries such as;

Mob / demobilisation Risk and measures

conditions etc.

• Machineries in good working 

submitted and accepted.

• All required documentation 

• Approval of machines by LTA / JV

accordance with design

• Area to park and steel plate layout 

machineries (giving FOS)

• Ground bearing for heavy 

Obtain other information such as;

Provide exclusion zone for mob‐demob activity

Conduct pre‐check prior mob/demob of machines

Alcohol check on operator  involved in mob/demob prior  operation

Mob / demobilisation Risk and measures

Traffic controllers  to guide  mob/demob  in/out site  assisted by LE and  relevant staff

Traffic control in place to ensure  smooth transition into worksite

Only relevant personnel are allowed to  get involved in mob/demob operation

Mob / demobilisation Risk and measures

Conduct briefing to relevant personnel involved in mob/demob activity

End

such work activities.

2) All site personnel should be fully informed and clear with the work process concerning 

measures to be adopted.

1) To identify the potential risk hazards concerning recharge well and the mitigation 

Objectives of this workshop (19):

Recharge Well Installation

Cooling Tower

Cooling Tower Works

Damaged to :

Recharge  well works

Insufficient  marking on  site.

Unplanned  Drilling.

Hazard  Cause

Permit to work system

Water pipe. Power grid  cables.

Risk 

Activity

1) Recharge well– Risk mitigation

Works at Ent. A

•

Trial Trench

LCDW  Carry out  cable  detection

‐

TBM briefing

Peter (JV Super)

Tan WC (JV UE) LCDW Tan WC (JV UE) Peter (JV Super) Peter (JV Super)

‐ ‐ ‐ ‐ ‐

• • • • • Thorough study of utilities drawings Cable detections by qualified LCDW Provide clear utilities marking on site Provide A3 size drawing of utility plan Apply permit to dig and implement “checklist  for working near utility” Barricade work area while drilling

Action Owner

Mitigation Measure

Damaged to :

Recharge  well works

Telecom  cables. High tension  cables.

Hazard 

Activity

•

•

•

• • • •

‐

‐

‐

‐ ‐ ‐ ‐

Peter (JV Super)

Tan WC

Peter (JV Super)

Peter (JV Super) Peter (JV Super) Peter (JV Super) Peter (JV Super)

Tan WC (JV UE)

‐

• Contact relevant utility agency for any  presence of unidentified utility Always treat utility as `live’ if encountered Only manual digging allowed for trial trench Full time supervision during trial trench  No mechanical drilling within 3m from  identified utilities. Brief utility plan in language understood by the  workmen. Provide watch man to watchout for utilities  during excavation Senior staff to be involved in site inspection  prior to PTW approval.

Action Owner

Mitigation Measure

Mark out detected cable clearly on site.  Drill only when identified cables are exposed.  Utilities marker are only allowed to shift or remove unless approved by JV UE.

Only manual  excavation is  allowed for  trial trench  works

Failure to  conduct  detection  test.

Hazard  Cause

1) Recharge well– Risk mitigation

Works at Ent. A

“A’ frame  topple

Recharge  well work

Fingers / hand  caught in  rotating parts

Injury to public

Risk 

Activity

Incompetent  crew

Poor ground  condition

Poor footage

Poor  mobilization  planning

Hazard  Cause

Recharge Well work – Risk mitigation

• •

• •

• •

•

‐ ‐

‐ ‐

‐ ‐

‐

JV Lift Engineer Sub‐con lifting supervisor

Sub‐con supervisor Sub‐con supervisor

Sub‐con supervisor Sub‐con supervisor

Sub‐con Engineer

JV Superintendent JV Supervisor

‐ ‐

• • Ensure work assess is planned. Ensure adequate access for work mobilisation  and public access. Only competent lifting crew is allowed to  involved in mobilisation. PTW‐Lifting approved prior unloading. Provide proper exclusion zone to segregate  work and public. Provide warning signs. Provide blinker lights to alert night motorist  and /or pedestrian. Ensure footage is firm and level at all times. Never drag load. Lift vertically.

Action Owner

Mitigation Measure

4) Recharge Well work – Risk mitigation

Sample of ground preparation for recharge well

Sample of exclusion zone for recharge well

Risk 

Silty water  flowing out of  work area /  public area

Activity

Recharge  well work

Incompetent  crew •

• •

•

Exposed  ground  condition

‐

‐ ‐

‐

‐

•

Poor planning

JV ECO

Sub‐con supervisor JV ECO

Sub‐con supervisor

Sub‐con Engineer

JV Superintendent JV Supervisor

‐ ‐

• •

Poor ECM  planning

Ensure minimum soil exposed area. All exposed soil to be covered with canvas  sheet Silty water to be channel to appropriate sump  for pumping into ECM plant. Silt fence to be put up prevent silty water from  flowing out of the site. No drilling work during wet weather condition. Ensure designated workers to standby and  ensure water treatment plant is powered and  properly connected for proper operation. Treatment plant to connect to permanent  power instead of generator.

Action Owner

Mitigation Measure

Hazard  Cause

Recharge Well work – Risk mitigation

Portable treatment plant commissioned to ensure silty  water are properly treated prior discharge into public  drain.

Drain Excavation Risks and Mitigation Measures

Sufficient manpower  deployed to ensure  silt are properly  maintain.

End

Minutes Title: Risk Register Workshop No 19 Date:7 Sep 2017 Time: 11.00am-12.00am Held at: LTA level 2 meeting room

Chaired by: Peter Nugent/ Jong Minuted by: Tommy Lee Distribution date: 29 Sep 17

Attendees list See attached

Apologies list

Page 1 of 2

Minutes ITEM

MATTERS DISCUSSED

1.0

Introduction

ACTION

Risk Workshop will be on Recharge well. The complete flow of the process will be demonstrated via a short slide presentation

Info

The project superintendent, Peter Nugent will present the presentation and the mitigation measures.

2.0

Slide presentation on Recharge well

2.1

T309P reminded JHZH to submit a set TRA audit records on a weekly basis.

Peter/ Jay Cel JHZH

TRA audit records was submitted on 3 Oct 17.

2.2

2.3

3.0

T309P commented on the filling and taking measurement for the water in the recharge well. The recharge well will be connected to the PUB water source. It is controlled by controlled valve, with flow meter and pressure gauge for switching on. For monitoring of water level and pressure, piezometer and water standpipe will be in place. Daily monitoring of water level will be carried out.

T309P requested to provide drawings for the recharge well. It will be provided in the submission.

JHZH

Any Other Matters: The next workshop topic will be proposed accordingly.

4.0

JHZH

INFO

Next Workshop The next workshop will be scheduled on 5 Oct 17. . It will be a weekly programme.

Page 2 of 2

All / Info

Sep 2017

Tommy Lee, Risk Management Facilitator

Civil Construction Safety Submission (CNSS) - Package 2

Construction of Siglap Station Thomson-East Coast Line

Contract T309

2

Doc no. T309-JHZH-PRS-PWD-GEN-0002

› Hazards and Mitigation Measures

› Instrumentation and Monitoring

› Construction Stage and Programme

› Geological Profile

› Value Engineering

› Optimization of Traffic Diversion

• Project Overview- Package 2

• PSR Committee endorsement scope

• Objectives

• Key Organization

• Major Key Dates

Content

3

Doc no. T309-JHZH-PRS-PWD-GEN-0002

: 30 June 2020 : 30 October 2020 : 28 February 2023

BSC- Entrance A

BSC- Entrance B,C,D

Completion of the Whole of the Works







Doc no. T309-JHZH-PRS-PWD-GEN-0002

: 30 June 2020

BSC of Station



4

: 17 March 2016

Contract Award



Major Key Dates



QP Design:



5

Doc no. T309-JHZH-PRS-PWD-GEN-0002

RC Subcontractor: China Jiangsu Construction Corporation

QP Supervision: LYL Consultants

One smart Engineering

Aurecon Singapore

Noma Consulting (Temporary Structure)

ARUP (Permanent Structure)

Main Contractor: John Holland Zhen Hua Joint Venture (JHZHJV)



Land Transport Authority

Client:



Key Organization

To demonstrate the control measures to mitigate these risks

To address the construction hazards and their mitigation measures

•To seek PSR committee’s endorsement to commence the works







6

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Package 1 Diaphragm wall, bored piles, ground improvement and enabling works Endorsed – Sep‘16 Package 2 Bulk Excavation, Strutting, Reinforced Concrete works, Flood Protection Plan. Submission – Sep’17

Our Submission for PSR committee’s Endorsement for Construction Activities are:

PSR Comm. Endorsement scope

To demonstrate the residual hazards transferred from Civil DSS



Objectives of Civil Construction Safety Submission are

Objectives

7

Package 2 – Project Overview

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Year 2016 to 2023

Project Timeline

8

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Package 2

• • • • •

U-shape canal upgrade

Box Culvert

Box Drain

Entrance D

Entrance A

9

Entrance C

Entrance B

Doc no. T309-JHZH-PRS-PWD-GEN-0002

1. Total Length: 350m 2. Top-down Station box (220L x 39W x 21D) 3. Cut & Cover Tunnel/Subway (77L x 6W x 21D) 4. Canal Upgrading (length - 157m) 5. 2 nos. Access Bridges to VS

Main Station

4 Entrances (Ent. A,B,C,D) 4 main slabs (Roof, Concourse, Platform, Under Platform) Parameter Dwall (0.8m/1.2m thick) Top Down Method Final Excavation level 22.6m

T309- Siglap Station

Victoria School

Villa Marina

Kee Sun Avenue

T309- Stakeholders

Laguna Park

Marine Parade Road

Elliot at East Coast

10

Doc no. T309-JHZH-PRS-PWD-GEN-0002

St Andrew’s Autism School

- 11 Traffic Diversions required till final reinstatement

Stage TD1C

WORK ZONE

• • • • • •

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Improved the overall safety on the project Separates the Construction Area to Public Elimination of High Risk Works Reduce complex temporary works Reduce congested work zone Reduce public crossing the live traffic

- 3 Traffic Diversions required till final reinstatement

Work Zone

Optimization of Traffic Diversion

Zone 1

Sheetpile

Zone 2

Sheetpile

Zone 3

Zone 4

Traffic Diversion TD1C

Value Engineering (Main Station)

Zone6

1

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Zone5

D-wall

The original Design

Value Engineering (Main Station)

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Value-Engineering Design

Cooling Tower/ Main Station

Geological Profile

14

Doc no. T309-JHZH-PRS-PWD-GEN-0002

D-wall toe level – 77-80 m RL

OA – 87-97 m RL

KF – 90-103 m RL

15

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Package 2 – Construction Stage and Programme

Nov 2018 May 2019 Apr 2019

Excavate & Construct Under Platform

Construct Platform

Internal Structure Works (incl. Ent A,B,C,D)

Sep 2020

Nov 2019

Sep 2019

Jul 2019

Mar 2019

Finish Date

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Jul 2018

Excavate & Construct Concourse

16

Nov 2017

Start Date

Excavate & Construct Roof Slab

Activity

Construction Stage and Programme

Zone 1

Zone 3

Zone 4

Traffic Diversion TD1C

Y

Zone6

Entrance B

1

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Zone5

Entrance C

Permanent openings (Use as construction openings)

Construction openings

Zone 2

Entrance D

Entrance A

Y

Construction Stage and Programme

103.3m RL 101.5m RL

Main Station

Sheet Pile

Section Y-Y

3.5m

Sheet Pile

Sheet Pile

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Cooling Tower

Excavate to Roof level at Cooling Tower

Main Station

98.00m RL

103.3m RL

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Cooling Tower Section Y-Y

Construct Roof Slab (Cooling Tower)

Main Station

98.00m RL

103.3m RL

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Cooling Tower Section Y-Y

Construct Roof Slab (Main Station)

Main Station

98.00m RL

103.3m RL

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Cooling Tower Section Y-Y

Stage 1D

Waterproofing above roof slab Backfilling to Ground level Stage 1D Road works, Implement Stage 1D

98.00m RL

103.3m RL

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Cooling Tower Section Y-Y

Stage 1D

Main Station

Excavate to Concourse

90.90 m RL

98.00m RL

103.3m RL

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Cooling Tower Section Y-Y

Stage 1D

Main Station

Construct Concourse Slab

Main Station

90.90 m RL

98.00m RL

103.3m RL

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Cooling Tower Section Y-Y

Stage 1D

Excavate to Under Platform Level

Main Station

82.63m RL

90.90 m RL

98.00m RL

103.3m RL

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Cooling Tower Section Y-Y

Stage 1D

Construct Under Platform Level Slab

Main Station

82.63m RL

90.90 m RL

98.00m RL

103.3m RL

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Cooling Tower Section Y-Y

Stage 1D

Construct Platform Slab Skin wall (1st lift) and Platform

Main Station

82.63m RL

90.90 m RL

98.00m RL

103.3m RL

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Cooling Tower Section Y-Y

Stage 1D

Construct Skin wall 2nd lift RC internal walls from Platform to Concourse

Main Station

82.63m RL

90.90 m RL

98.00m RL

103.3m RL

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Cooling Tower Section Y-Y

Stage 1D

Construct Skin and RC internal structures from Concourse to Roof

Main Station

82.63m RL

90.90 m RL

98.00m RL

103.3m RL

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Cooling Tower Section Y-Y

Stage 1D

Construct RC Structures to Threshold level Above ground structures

4a

3a

Stage 1C Road Diversion

4a

3a

5

4

3

2

1

Sequence

4

2

Activity Name

[TD1C] [Z2] [GL 1 to 6, A to E] Construct Roof Slab

[TD1C] [Z2] [EA] Construct Roof Slab

[TD1C] [Z6] [EB] Construct Roof Slab

[TD1C] [Z4] [GL 15 to 18+ / A to E] Construct Roof Slab

[TD1C] [Z3] [GL 6 to 15 / A to E] - Construct Roof Slab

[TD1C] [Z4] [CT] Construct Roof Slab

[TD1C] [Z3] [CT] Construct Roof Slab

3

1 5

04-May-18

05-Mar-18

07-Feb-18 06-Mar-18

22-May-18

20-May-18

14-Apr-18

20-Jan-18

09-Jan-18

Finish

09-May-18

15-Apr-18

26-Jan-18

10-Dec-17

07-Dec-17

Start

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Construction Stage and Programme

3

2

Stage 1D Road Diversion

6

5

4

3

2

1

Sequence

[TD1D] [Z6] [EB] Construct Remaining Roof Slab

[TD1D] [Z5] [EC] Remaining Structure Works to Roof

[TD1D] [Z5] [EC] Construct Roof Slab

[TD1D] [Z1] [ED] Construct Roof Slab

[TD1D] [Z2] [GL 1 to 3, A to C] Construct Roof Slab

[TD1C] [Z5] [EC] [SUB] Construct Roof Slab

Activity Name

4

1 5

6

15-Mar-20

31-Oct-19

18-Feb-19

22-Jan-19

01-Jan-19

29-Sep-18

Start

28-Mar-20

09-Dec-19

03-Mar-19

18-Feb-19

21-Jan-19

01-Nov-18

Finish

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Construction Stage and Programme

32

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Package 2 – Instrumentation and Monitoring

30

Settlement contour

33

30

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Monitoring for stakeholders

Instrumentation and Monitoring

34

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Monitoring for Station works

35

Instrumentation and Monitoring

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Monitoring for Utilities

36

Traffic Diversion 1C

Instrumentation and Monitoring

Doc no. T309-JHZH-PRS-PWD-GEN-0002

37

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Package 2 – Hazards and Mitigation Measures

Excavation and Strutting RC Works Box Culvert Works

5 18 52 2

A B C D

-

No.

Risk Class

Summary Initial Risk Class

38

A B C D

Risk Class

0 0 74 3

No.

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Intolerable Undesirable Tolerable Acceptable

Summary of Residual Risk Class

Civil Construction Safety Submission (CNSS)

39

Doc no. T309-JHZH-PRS-PWD-GEN-0002

ES1.Instability of ERSS/ temporary Works ES2.Ground instability during excavation ES3. Prevention of excessive wall deflection and ground movement ES4.Noise Protection Measures ES5.Vibration Protection Measures

Associated with Excavation and Strutting Works

Hazards

Doc no. T309-JHZH-PRS-PWD-GEN-0002

 Sufficient review of instruments monitoring results by Instrument Engineer and QPS

 Independent Instrumentation Monitoring Specialist

 Ensure construction sequence is in accordance with design

ES1. Instability of ERSS/ temporary Works

Instability of temporary works (station boxes or linkways)

Hazard

Hazard Cause

• Poor workmanship

• Insufficient control of the works

•Insufficient monitoring

•Design implementation incorrect

Identified Risks

41

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Good control on the welding quality – UT for butt weld & MPT for fillet weld

•Ensure correct grade, dimensions of steel materials used in strutting system as per details construction drawings.

•Close coordination and required actions to be carried out by CM

•Review of monitoring results by instrumentation engineer and QPS

•Independent Instrumentation / monitoring to monitor strut loads

•Ensure construction sequence is in accordance with design

Mitigation Measures

ES1. Instability of ERSS/ temporary Works

-

-

42

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Recharge well to be installed before excavation commences

ES2. Ground instability during excavation

-

43

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Monitor alert level and suspension level of instruments Ensure all instrumentation are in place before excavation commencement Excavation sequence in accordance with design

ES2.Ground instability during excavation

Ent D

Ent C

Subway

44

Locations of strain gauge

Location of Load Cell Doc no. T309-JHZH-PRS-PWD-GEN-0002

Ent B

 Monitor inclinometer (daily) and strut load readings (real-time)

 Independent monitoring of ERSS including struts loads, and joint review of instrumentation results by Instrumentation Engineer & QP(S).

 Excavation sequence in accordance with design

ES3.Excessive wall deflection and ground movement

Zone 1

Noise Barrier

Zone 2

Zone 3

Zone 4

Traffic Diversion TD1C

ES4. Noise Protection Measures

Zone6

4

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Zone5

    

46

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Equipment and machinery with noise insulating material Setting up of noise barrier around work site Monitoring of site noise level and keep within limits Adhere to designated work hours Keeping stakeholders informed on activities and gather feedback

ES4. Noise Protection Measures

Zone 1

Zone 2

 Noise Monitoring

Zone 3

Zone 4

 D-wall and buttress wall remove by wire cut

ES5. Vibration Protection Measures

Zone6 4

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Zone5

Wirecutting of D-wall

Hazard

Hazard Cause

•Breakage of wire during cutting

Identified Risks

48

Doc no. T309-JHZH-PRS-PWD-GEN-0002

• Hoarding/ Protection shield of wire breakage and loose material

• Approved safe work procedure in place

• Machinery to be maintained as per manufacturers requirements

• Trained and experienced operator to utilise machinery only

• Proper guard of around moving parts of the machine

• Ensure safe distance to wire saw is in place during cutting process (remote control when possible)

• Dedicated exclusion zone maintained around work area, no access by personnel during wire cutting process

Mitigation Measures

ES5. Vibration Protection Measures

49

Doc no. T309-JHZH-PRS-PWD-GEN-0002

RC1.Fall from Height RC2.Working in Confined Space, Hazardous atomsphere RC3. Formwork Structural Failure RC4. Failure in Concrete Placement RC5. Water Leakage between D-wall and Slab

Associated with RC Works

Hazards

Zone 1

Zone 3

Y

Zone 4

Traffic Diversion TD1C

Y

Zone6

Entrance B

5

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Zone5

Entrance C

Permanent openings (Use as construction openings)

Construction openings

Zone 2

Entrance D

Entrance A

RC1- Fall from Height

-

-

TYPICAL EXAMPLE OF CONSTRUCTION OPENINGS AND REQUIREMENT FOR EDGE PROTECTION

Guard rail

Retaining wall

51

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Retaining Wall to be cast (Roof Slab level) Guard Rail to be installed (Concourse level and below)

RC1 - Fall from Height

Fall from Height - Construction openings - Penetration covers

Hazard

• Penetration covers to be mechanically secured

•Penetration covers not secured

52

Doc no. T309-JHZH-PRS-PWD-GEN-0002

• Maintain clear exclusion zone for no storage of material near openings

• Placing of signages to warn of lifting activities/ drop objects around openings

• Proper access/ ladders/ platforms as provided in designated locations

• Construction openings to be secured with guard rail/ cast with retaining wall (secured with edge protection)

•Temporary Construction Openings not secured

Mitigation Measures • Ensure edges are barricaded (with netting) when possible

Hazard Cause

•Working at edge

Identified Risks

RC1. Fall From Height

Working in confined space or constrained site

Hazard

Hazard Cause

•Handling of temporary steelwork within confined site

•-Craning steel members through restricted worksite openings

•Hazardous atmosphere

•Ventilation insufficient, Lighting insufficient

•Staff identification not accounted

Identified Risks

53

Doc no. T309-JHZH-PRS-PWD-GEN-0002

•Signal man to guide operation, tag line when possible

•Dedicated site safety officer

•Securing material on site, inspection by lifting supervisor on lifting prior to lifting

•Planning of storage and handling routes within crane age access

•Barricade of work zone

•Approved lifting plan and method statement in place

• Provision of gas detectors and monitoring every 4 hours interval

• Provision of adequate pumps and blowers, Installation of ventilation duct

•Adequate construction works and ventilation

•Design adequate space for machinery

•Installation of lighting

• Implement Confined Space permit systems

• Implementation of RFID system to monitor the movement of workers working inside station box

• Adhere to confined spaces specification

Mitigation Measures

RC2- Working in Confined Space

Doc no. T309-JHZH-PRS-PWD-GEN-0002

ENT “A” ,COOLING TOWER & ENT “B” EVACUATION ROUTE

Emergency Response

Doc no. T309-JHZH-PRS-PWD-GEN-0002

ENT D & SIGLAP LINK EVACUATION ROUTE

Emergency Response

Wall System Formwork 56

Temporary Propping as part of Design (Stairshaft landing, bottom up construction)

RC3. Formwork Structural Failure

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Scaffold System

-Use of insufficient or poor quality material and poor design

-Installation not as per PE shop drawings

•Design/ installation not being certified by PE

•Ground foundation unstable

•Early formwork removal

Hazard

•due to poor workmanship

•Structural failure due to use of insufficient or poor quality material and poor design

•Ground not compacted to specification, due to insufficient lining of blinding concrete

•The formwork dismantling shall be cordoned off in order to prevent unauthorized entry into work area

•Structural failure due to unauthorized removal prior to concrete achieving design strength

57

Doc no. T309-JHZH-PRS-PWD-GEN-0002

• Emergency response planning including Contingency planning

• Ensure material and design and approved and installed accordingly

•Supervision by engineer to ensure installation is as per shop drawings and according to method statement and RA assessment

•Inspection by PE prior to concreting

•Formwork design shall be endorsed by PE

Ground shall be compacted and level/ cast with blinding concrete

•Proper formwork removal sequence to be followed

•Temporary props are to be secured and not removed unless approved by engineer

•Ensure concrete strength is achieved prior to removal

•Removal inspection checklist to be endorsed

•Formwork removal shall be approved by formwork supervisor.

Mitigation Measures

Hazard Cause

Identified Risks

RC3. Formwork Structural Failure

58

Concrete will typically be placed via concrete boom pump and static lines

Doc no. T309-JHZH-PRS-PWD-GEN-0002

RC4. Failure in Concrete Placement

Concrete Fall from Height Placement with boom/ line/ stationary pump

Hazard

Hazard Cause

•Fatigue management of workers

•Hit by loose concrete

•Concrete pipe burst or choked during concrete casting

•Penetration covers not secured

•Failure of static •Temporary Construction line while Openingsconcrete pumping

•Working •Poor ground at edge conditions

Identified Risks

Additional bin to catch the spillage

59

Doc no. T309-JHZH-PRS-PWD-GEN-0002

• Ensure workers are working on a shift and provide adequate shades/ protection/ water to keep workforce hydrated and alert

• - Use of gunny sack/ bend the rubber hose

• - Use of tagline (for rubber hose)

• If choked or pipe burst, stoppage of work and isolate the issue. Address the issue through close coordination between concrete pump operator and supervisor.

• Static line pipe to be fixed to temporary concrete anchors in accordance with manufacturers recommendations

•

• Ensure ground condition is survey necessary COS is edges are barricaded whenand possible obtained (if applicable) • Use of safety harness • Static line shall be regularly maintained and checking during pre• Construction openings to be covered when not in use at all times start and regular inspections. • Penetration covers to be secured • Spare lengths of rubber concrete hose and steel static line pipe • Proper access/ on ladders/ platforms as provided to be available site during concrete pour • Placing ofcoupling signagesoftostatic warnline fall from height locations Sufficient

Mitigation Measures

RC4. Failure in Concrete Placement

60

Doc no. T309-JHZH-PRS-PWD-GEN-0002

RC5. Water Leakage between D-wall and Slab

Leakage at the interface between Dwall and Roof/ Concourse

Hazard

• Define levels of leak treat accordingly, mark affected area

• Honey comb in concrete

61

Doc no. T309-JHZH-PRS-PWD-GEN-0002

• Approved method statement for different D-wall leakage scenarios in place

• Apply grouting/ injection on affected zone

• Review suitability of grouting system

Perform regular inspection during RC work activities

•

• Poor workmanship

Mitigation Measures • Ensure all D-wall activities control are in place (e.g.water-stop joints, concrete pouring and curing, alignment, rebar placement)

Hazard Cause

• Waterstop joints not continuous

Identified Risks

RC5. Water Leakage between D-wall/ Roof or Concourse

Canal Upgrading Works

62 62

Doc no. T309-JHZH-PRS-PWD-GEN-0002

63

BC1. Flood from Opera Estate Canal BC2. Silty Water Discharge into Canal BC3. Damage to utility bridge

Associated with Box Culvert Works

Hazards

Doc no. T309-JHZH-PRS-PWD-GEN-0002

64

Doc no. T309-JHZH-PRS-PWD-GEN-0002

 Sheetpile to enclose the work area and prevent flooding

BC1. Flood from Opera Estate Canal

Discharge into Canal/ Drain during heavy rain

Hazard

•ECM Plan in place

•Surface run off, construction material (bentonite, concrete, grout)

65

•Contingency planning

Doc no. T309-JHZH-PRS-PWD-GEN-0002

•Regular inspection on site by ECO at affected zones

•Silt fence protection at all open drains/ canal

•Insufficient control on site

Mitigation Measures •Concrete/ Retaining wall for flood mitigation

Hazard Cause

•Heavy rain

Identified Risks

BC2- Silty Water Discharge into Canal

66

BC3- Damage to utility bridge

Doc no. T309-JHZH-PRS-PWD-GEN-0002

Damage to LV cable HV cable

Damage to water pipe

Hazard

Hazard Cause

•Excavator hitting protection pipe

•Accidental damage

•Excavator hitting protection pipe

•Accidental damage

Identified Risks Mitigation Measures

67

Doc no. T309-JHZH-PRS-PWD-GEN-0002

• Positive identification of utiltiies

• Serve affect resident notice during water diversion works

• Apply Utilities service damage plan and utilities prevention plan

• Clear demarcation of work zone

• Ensure team is at work zone within 1hour of issues

• Additional cables to create slag and prevent tension

• Use of heavy duty flexible hose to protect cable

• Bracket to be fabricated and installed according to design and use of correct material

• Positive identification of utiltiies

• Elbow joints to be haunched

• PUB Technician to supervise valve closing operation

• Supply of water bag/ water tank during water disruption by PUB

• Apply Utilities service damage plan and utilities preventation plan

• Clear demarcation of work zone

• Ensure team is at work zone within 1hour of issues

• Bracket to be fabricated and installed according to design and use of correct material

BC3- Damage to utility bridge

68

Thank You

Doc no. T309-JHZH-PRS-PWD-GEN-0002

No 1 Hamsphire Road Block 1 Level 4, Singapore 219428 Tel: (65) 6396 2178

PSR(SUB-COMMITTEE) MEETING

Page 1 of 15 Prepared by : Tan Ming Wooi, PRE(GTT) Vetted by (PRMGTT)

: Dr Chepurthy Veeresh

Approved by : Ow Chun Nam (representing Chairman) AGENDA: 1. Presentation on T315 CNSS for Underpass and A&A Construction with Related Viaduct and Stitching Works 2. Discussion on T315 CNSS for Underpass and A&A Construction with Related Viaduct and Stitching Works 3. Presentation on T309 CNSS Bulk Excavation, Strutting, Flood Protection Plan, Decking and Reinforced Concrete Works 4. Discussion on T309 CNSS Bulk Excavation, Strutting, Flood Protection Plan, Decking and Reinforced Concrete Works 5. Presentation on T212 CNSS CP Permanent Lining & Waterproofing Works 6. Discussion on T212 CNSS CP Permanent Lining & Waterproofing Works 7. Follow-Up Presentation on T301 CNSS Amendment on Bulk Excavation on Rail Depot – Package 2a 8. Discussion on T301 CNSS Amendment on Bulk Excavation on Rail Depot – Package 2a 9. Confirmation of 167th PSR Sub-Committee Minutes of Meeting 10. Next Meeting MEETING ATTENDED BY: PSR (Sub-Com) Members: Ow Chun Nam Song Siak Keong Dr Chepurthy Veeresh Andrew Tan Absent with Apologies: Paul Fok Choo Chai Foong

Ad-hoc Participants: D(TUN) D(CT3)DTL3 PRM(GTT) Representing DDGTT M(SH) Representing DDSA GDIDE DyGDIDE(ISP)

Aman Aboobucker Diong Kim Jun Tan Jui Hock Heng Kok Hui

LCBC LCBC LCBC Tritech

Chuah Eow Tong

Tritech

Hector Perez Ooi Ah Choon Simon L

LTA LTA JHZH

PSR SUB-COMMITTEE MEETING Meeting No: 165 No

Page 2 of 5 Report By: Tan Ming Wooi

Item Discussed

Goh Kok Hun Rama Venkta Chuah Han Leong Liu Png Hock Chelliah Murugamoorthy R Jaysankar Henry Foo Goh Kok Hwa Tan Kian Tong Tan Kok Jin Kulaindran Ariaratnam Chang Kin Boon Simon Hoblyn Alvin Soong

Action

Frank Yi JHZH Chan Gi Jeong JHZH Tommy Lee JHZH Aris Himawan Arup Yong Kuan Yau LYL/QPS Vima LTA Juthamard Subongkot LTA Kong Xiaolei LTA N. Nakamura SKS Masaaki Suzuki SKS RKChaudhary Kenhin Ei Ei Nue Calibre Danilah Norahim Lee Calibre Sharul Rizal LTA Mohiadeen LTA Lin Su Qi LTA Darryl Chen LTA Kek Shu Hua LTA Wong Dikai LTA Jay Jeong GS R. Sarvananthan GS M. Givakumar GS Dae Young You GS Richard Ting TYLin Khoo Kok Sing TY Lin Hu Xiang Bin R&K Siew Kim Choi R&K Hoon Yat Meng LTA CC: Chairman PSR(Road & Rail), Secretary PSR (Road), Secretary PSR (Rail)

3 3.1

4

DD(GTT) DCL D(RLE) DSPP D(CT1)DTL3 DCPRF D(CT3)TEL D(CT1)TEL D(CT6)TEL D(CT2)TEL 1D(CT5)TEL D(CT2)DTL3 1DD(TUN) DDSA

Presentation on T309 CNSS Bulk Excavation, Strutting, Flood Protection Plan, Decking and Reinforced Concrete Works Mr Tommy Lee (RMF) from John Holland Zhen Hua JV (JHZH) presented on T309 CNSS Bulk Excavation, Strutting, Flood Protection Plan, Decking and Reinforced Concrete Works.

Info

Discussion on T309 CNSS Bulk Excavation, Strutting, Flood Protection Plan, Decking and Reinforced Concrete Works

PSR SUB-COMMITTEE MEETING Meeting No: 165 No

4.1

Page 3 of 5 Report By: Tan Ming Wooi

Item Discussed

D(TUN) raised concerns about the following risk whether these have been addressed: -

Action

T309

Bored pile necking Bored pile not in position Water-stop bar

JHZH to revert and clarify. JHZH Response: Bored pile necking and bore pile not in position risks will be added. Water stop bar risks have been addressed in the risk register. 4.2

D(TUN) reminded T309 to include a shying distance when placing barriers on the roads to prevent motorist from the tendency of going into other’s lane.

Info

JHZH Response: Will comply. 4.3

D(TUN) pointed out that AE should come out with a new risk register for the value-engineering. JHZH to revert and clarify.

T309

JHZH Response: JV will request AE for a new register for value engineering. 4.4

JHZH concurred with D(TUN)’s advice to provide a good clutching sheet pile system to ensure water-tight structure.

T309

JHZH Response: Current sheet pile system is using a clutch interlocking method. 4.5

D(TUN) queried about the type of ventilation system that JHZH would be providing. JHZH to revert and clarify.

T309

JHZH Response: Will be using force and extraction ventilation method. 4.5

D(TUN) spoke about the risk associated with working inside a confined space and asked whether JHZH has address the following: -

Evacuation (track the worker at entry and exit point through RFID and biometric system) Lifting Concreting Management of fire hazard (no tarpaulin sheets allowed and duct must be fire-retardant)

T309

PSR SUB-COMMITTEE MEETING Meeting No: 165 No

Page 4 of 5 Report By: Tan Ming Wooi

Item Discussed

-

Action

Ventilation (air change, chiller, etc.) Fire staircase route

JHZH to revert and clarify. JHZH Response: All the above risks have been addressed in the risk register 4.6

D(TUN pointed out that leakages of diaphragm wall must be addressed immediately and not wait until the end of excavation. It must be carried It must be sealed off before proceeding to the next stage of excavation. JHZH informed they would conform.

Info

JHZH Response: Will comply.

4.7

D(TUN) asked JHZH to ensure the subgrade underlying the roof slab must be sufficient to support the slab because of the presence of Kallang Formation. JHZH noted they would conform.

Info

JHZH Response: Will comply.

4.8

On the issue of cutting the diaphragm wall, D(TUN) was concerned about the vibration induced by the hacking of the diaphragm wall would damage the waterproofing membrane. JHZH to revert and clarify.

T309

JHZH Response: Hacking and cutting of diaphragm wall method will be used. Both options and the waterproofing membrane detailing will be reevaluated prior to commencement of works. 4.9

D(TUN) reminded JHZH to capture whatever that’s left behind of the temporary works after the construction to be reflected in the as-built drawing. JHZH noted they would conform.

Info

JHZH Response: Will comply and is currently in practise.

4.10

JHZH concurred with D(TUN)’s suggestion to ensure the excavation area in the station should be lighted up just as good as what is practice (100 lux) in the tunnel. JHZH Response: Noted.

Info

PSR SUB-COMMITTEE MEETING Meeting No: 165 No

4.11

Page 5 of 5 Report By: Tan Ming Wooi

Item Discussed

D(TUN) reminded to have dedicated power points and not loose points on the floor which can cause risk of tipping hazard due to cables laying around on the floor. Cables like that could cause electrocution if floor is wet. JHZH noted they would conform.

Action

Info

JHZH Response: Cables will be hung on mounted brackets and sufficient power points will be allocated for tapping of power within the work zone premises.

4.12

D(TUN) raised concerns about pipe burst connecting the concrete boom pump especially at the joint which is prone to breakage if the joint is the groove type. He asked JHZH to check on this. D(CT3)DTL3 added that the line could only be used for a certain period of time Checking must alert the sub-contractor to change it if necessary. JHZH noted and would engage the right sub-contractor.

Info

JHZH Response: Joints will be inspected periodically and change when necessary. JV had engaged CJCC as the RC works subcontractor. 4.13

D(TUN) cautioned not to use tarpaulin sheet to cover concrete during curing as the material is flammable. JHZH noted and would conform.

Info

JHZH Response: Will comply. 4.14

IR mentioned that all other comments given to T309 CNSS Bulk Excavation, Strutting, Flood Protection Plan, Decking and Reinforced Concrete Works had been addressed. IR recommended PSR SubCommittee to endorse the CNSS for T309.

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4.15

PSR Sub-Committee endorsed T309 CNSS Bulk Excavation, Strutting, Flood Protection Plan, Decking and Reinforced Concrete Works subject to comments and recommendations made.

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Sheet Piling.

2) All site personnel should be fully informed and clear with the work process concerning 

to be adopted.

1) To identify the potential risk hazards concerning Sheet Piling and the mitigation measures 

Objectives of this workshop (no.21):

1

Total distance

55m

22.6m

97.6m

65.3m

8.3m

ID

1

2

3

4

5

4

2 3

21 Nos

163 Nos

244 Nos

57 Nos

138 Nos

Sheetpile qty

Sheet Piling locations and programme (ERSS)

5

12m

6m

6m

12m

12m

Sheetpile length

15 Dec – 18 Dec 17

6 Dec ‐14 Dec 17

21 Nov‐ 5 Dec 17

15 Nov‐ 20 Nov 17

6 Nov‐ 14 Nov 17

Construction Timeline

Section of Sheet Pile

1. 2. 3. 4. 5. 6. 7. 8. 9.

Mobilization/ Demobilization of machinery Collision of Machinery and Site staff Accidental dislodge of sheet pile during driving Welding‐ Fire damage Failure of lifting mechanism Noise Protection Measures Damaged to: 1) Water pipe 2) Bentonite pipe Gaps in sheet piles Sheetpile stacking

Hazards

Mobilization of Machinery

Hazard 

Installation  Mobilization  of sheet  and  pile Demobilization  of machinery

Activity

Mitigation Measure ‐ Ramp width to be min. track width of crane ‐ Experience operator ‐ Banksman to guide the crane during operation ‐ Safety zone to be established ‐ Barricade the operation zone ‐ Establish safe work procedure

Hazard  Cause

‐Toppling of  crane ‐Ramp failure ‐Inexperience  operator

SheetPiling Risks and Mitigation Measures

Walter Lai/ Fan Yuhua Walter Lai Walter Lai Walter Lai/ Crawford Walter Lai Walter Lai/ Crawford

Action Owner

Hazard 

Hazard  Cause

‐Submit lifting plan and machinery record prior to  start of operation ‐Provision of signalman and traffic controller to  guide machinery movement ‐Full compaction and void filled with quarry dust  or mill waste.  

Absence of  lifting plan

Failure to  guide  machineries  movement

Uneven  ground

‐Establish good communication at all times  between operator and signalman ‐Used of tag line to control swaying of load. ‐Provision of steel plate for machinery

‐Ensure work zone is organized with good housekeeping ‐Proper barricade and demarcation of work zone  to prevent unauthorized entry

Mitigation Measure

Negligence of  operator

Installation  Collision of  Constraint of  of sheet  machinery and  work zone  piles site staff

Activity

SheetPiling Risks and Mitigation Measures

Walter Lai

Walter Lai/ Killi

Walter Lai

Walter Lai

Walter Lai/ Fan Yuhua

Walter Lai/ Jessica Ng

Action Owner

Accidental  dislodge of  sheet pile  during driving

Installatio n of sheet  piles

Negligent  operator Faulty vibro head

Hazard  Cause

Walter Lai

Walter Lai

Action Owner

Sling will only be removed after sheet pile is fully  driven into the ground.

Employ skilled operator and perform daily  checks prior to start of operation Additional sling tied to sheet pile and machine  as extra protection in case if grabber gives way.

Mitigation Measure

Additional sling tied to sheet pile and machine

Hazard 

Activity

SheetPiling Risks and Mitigation Measures

Hazard 

Hazard  Cause

Installatio Using of poor  Structure  n of sheet  condition  failure of  piles machinery machinery

Activity

Maintenance  service report,  AE inspection  checklist and  certificate

Action Owner

Machine to be inspected and certified by AE. Walter Lai Regular monthly maintenance of machinery 

Mitigation Measure

SheetPiling Risks and Mitigation Measures

Ensuring the alignment and verticality of the pile. 

SheetPiling Risks and Mitigation Measures

Hazard 

Hazard  Cause

Mitigation Measure

Installatio Failure of  n of sheet  lifting  pile mechanism

Brake motor  failed Failure of  sling and  chain

Monthly inspection of lifting mechanism Colour coding all lifting mechanisms Safety zone to be established Lift load for 3 sec, 300mm and personnel 3  m away

Installatio Welding‐ Fire  Combustible Clear of combustible material  n of sheet  damage material pile Inappropriat Provide PPE‐ Welding face shield, apron,  gauntlet e welding  Daily welding set checklist/inspection rod Provision of fire blanket and fire  extinguisher

Activity

SheetPiling Risks and Mitigation Measures

Walter Lai/ Killi Walter Lai Walter Lai/ Crawford Walter Lai

Walter Lai Crawford Ang

Walter Lai

Walter Lai/ Fan Yuhua

Action Owner

    

Equipment and machinery with noise insulating material Setting up of noise barrier around work site Monitoring of site noise level and keep within limits Adhere to designated work hours Keeping stakeholders informed on activities and gather feedback

Noise Protection Measures

SheetPiling Risks and Mitigation Measures

12

Damaged to : ‐Unplanned  excavation ‐Water pipe ‐Insufficient  marking on  ‐Bentonite  site pipe ‐Failure to  conduct  detection  test

Locating  of Utility  services 

Hazard  Cause

Hazard 

Activity

‐If unclear with the finding of services after  reaching the 2m limit, conduct further  detection to determine the presence of any  services below.

Tan WC/ Walter Lai Tan Hock Huat/ Tan WC Tan WC Tan WC Walter Lai Walter Lai Tan WC

‐Thorough study of utilities drawings ‐Cable detections by qualified LCDW ‐Provide clear utilities marking on site ‐Provide A3 size drawing of utility plan ‐Apply permit to dig ‐Barricade work area while trenching ‐Contact relevant utility agency for any  presence of unidentified utility ‐Always treat utility as `live’ if encountered ‐Only manual digging allowed for trial trench ‐Full time supervision during trial trench 

Tan WC

All Walter Lai Fan Yuhua/ Thomas Ng

Action Owner

Mitigation Measure

SheetPiling Risks and Mitigation Measures

Hazard 

Hazard Cause

Installatio Gaps in sheet  '‐ Leakage through  n of sheet  piles gap in the walls piles ‐Damage to services Groundwater  drawdown ‐ Localized collapse  of soil in the gap  during excavation

Activity

SheetPiling Hazards and Mitigation Measures

Walter Lai/ Fan Yuhua

Minimize gaps by interlocking  sheetpile‐ Utilities diverted from excavation  wherever possible ‐ Instrumentation around gap area  when necessary

Olive/ Walter Lai

Tan WC/ Walter Lai

Action Owner

Mitigation Measure

SheetPiling Risks and Mitigation Measures

Standard Weight of Material

8.6.3) Sheet pile stacking rules - Not more than 4 pieces of sheet pile 2 layer 1000 mm high for stacking sheet pile.

THANK YOU

General Hazards 8. T309/CNSS/121/001‐ Fire or explosion during construction (Page 20) 9. T309/CNSS/997/004‐ Toppling of crane, Ramp failure, Inexperience operator (Page 25) 10. T309/CNSS/999/015‐ Fire explosion due to gas leak (Page 27) 11. T309/CNSS/999/016‐ Electrocution due to electrical leak (Page 27)

New/Revised Risk:   D‐wall 1. T309/CNSS/100/008‐ Instability of temporary works (trenches), open trench, open trench w/o cage, open trench w/  cage (page 4) Bulk Excavation 2. T309/CNSS/104/003‐ Ground instability during excavation to strut S1 level for area with the diverted traffic.  (Page 11) RC Works 3. T309/CNSS/117/011‐ Concrete Placement with boom/ line/ stationary pump (Page 17) 4. T309/CNSS/117/017‐ Strutting failure (Page 18) 5. T309/CNSS/117/018‐ Work from height (Page 18) 6. T309/CNSS/117/019‐ Overloading of Structural slab (Page 18) 7. T309/CNSS/117/020‐ Reinforcement collapse – horizontal slab, walls (Page 18)

Closed Risk:  T309/CNSS/109/002‐ Obstruction of seawall (Page 14)