20051201 Fire Risk
This document was uploaded by user and they confirmed that they have the permission to share it. If you are author or own the copyright of this book, please report to us by using this DMCA report form. Report DMCA
Overview
Download & View 20051201 Fire Risk as PDF for free.
More details
- Words: 1,847
- Pages: 28
Fire Risk in Metro Tunnels and Stations
The Hong Kong Institution of Engineers, Building Services Division
Hyder Consulting
Presented by:
Dr. Leong Poon Ir. Richard Lau 1 Dec 2005 © Hyder Consulting Pty Ltd
Road tunnels
Sydney Harbour tunnel
Melbourne city link
M5 East tunnel
Cross city tunnel
Western Harbour, HK
Eastern Harbour, HK
© Hyder Consulting Pty Ltd
2
Rail tunnels
Tseung Kwan O Ext., HK New Southern Railway, Sydney Parammatta Rail Link, Sydney GZ Metro
© Hyder Consulting Pty Ltd
West Rail, Mei Foo – Nam Cheong tunnel , HK
3
Stations and platforms, international
Stratford Station Concourse, UK Berlin Hauptbahnhof Station, Germany
Federation Square, Melbourne
© Hyder Consulting Pty Ltd
4
Stations and platforms, East Asia
Guangzhou Line 4 (Huangzhou Station) KCRC West Rail DD400, HK Nam Cheong Station, HK
© Hyder Consulting Pty Ltd
GZ Metro Line 1 Lai King Station, HK
5
Metro Tunnels and Stations – General Characteristics
Limited to metropolitan area (hence the name) Entire network is underground Interspersed by stations every 500 – 800m Predominantly one-way flow (ie single bore)
© Hyder Consulting Pty Ltd
6 Route 8 Cheung Sha Wan to Shatin
Metro Tunnels and Stations – Safety (or risk) characteristics
Traffic is well controlled, hence low accident rates Combustible material is controlled, hence low fire hazard Closely spaced stations allow train to continue to the
station to allow passenger evacuation and fire-fighting Single bore tunnels lack escape passages unlike twin bore tunnels, hence relatively higher risk Large concentration of users, hence any incident places many passengers at risk
© Hyder Consulting Pty Ltd
7 Guangzhou Metro Line 4 - Huangzhou Station Detailed Design
Metro Tunnels and Stations – Objectives (of risk assessment)
Identify relevant fire risks What factors cause incidents/disasters Determine key factors for improving safety Determine recommendations for effective fire protection measures
© Hyder Consulting Pty Ltd
8
Literature Review – Statistics
Cause of fires in metro rails:
Ignition from mechanical/electrical failure, fuel from debris, cabin material & baggage, terrorist activities? Mechanical 13%
Station 17%
Not specified 13% © Hyder Consulting Pty Ltd
Arson 13% Cigarette 10%
Electrical Fault 34%
9
Literature Review – Statistics
Rate of occurrence:
Small rail fire ~ a few a year Severe rail fire ~ 0.5 a year worldwide (Anderson & Paaske)
30 severe incidents 1970-1987
43 fatalities in 5 incidents (King’s Cross = 31)
London underground, July 2005 (terrorist attack)
50 fatalities (> sum of all past records)
Demand for rail metro usage increasing © Hyder Consulting Pty Ltd
Throughput of 26 billion a year Hence potential exposure higher – ie more at risk 10
Literature Review – Fire Hazard
Carriage – main source of fuel + baggage Fire size typically between 6-20 MW Control of lining material will reduce likelihood of fire
development but not necessarily reduce the fire size Terrorist factor ? Significant but highly indeterminate – best handled through a risk assessment approach
© Hyder Consulting Pty Ltd
11
Literature Review – Fire Protection Systems
Purpose is to detect, warn and control For stations, conventional building systems are provided For carriages/tunnels, the following are provided: Detection: – Smoke detectors in air-conditioned carriages – Heat detectors/CCTV may be used in tunnels
Warning:
– Communication systems include break-glass, intercom phone or PA system for staff and passengers
Control:
– Fire suppression systems in engine/equipment areas – Portable systems in passenger area
© Hyder Consulting Pty Ltd
12
Literature Review – Smoke control in tunnels
Smoke control is a key fire protection provision Strategy is to take advantage of longitudinal ventilation Force smoke downstream in the direction of
travel towards the ventilation shaft to be exhausted Passengers take the smoke clear path upstream of air flow Escape stairs may be required for long tunnel sections Escape stairs also used by fire fighters to gain access Train should continue to the next station to facilitate egress and fire-fighting access
© Hyder Consulting Pty Ltd
13
Basic smoke control strategy – Schematics
Direction of longitudinal ventilation Exit
Smoke clear path
Occupant evacuation
© Hyder Consulting Pty Ltd
Downstream
Smoke exhaust
14
Risk assessment concept
Risk is a measure of the consequence of an event, i.e. Risk = Probability × Consequence
Consequence is the estimated measure of the event eg no of fatalities, cost of damage
This is a generic approach – can be readily applied to
assess situations where design is difficult to quantify Life safety and monetary loss usually expressed separately, unless relationship exists, eg 1 fatality = $?????
© Hyder Consulting Pty Ltd
15
Risk assessment application
Main use of risk assessment is as a tool to determine a cost-effective solution by:
Identifying important factors affecting life safety (or cost) Identifying effective protection measures
Effectiveness of each system is measured by its:
Reliability – likelihood of the system operating, and Efficacy – how well it performs its intended function.
A cost-effective solution is the least cost design meeting acceptable level of safety requirements
© Hyder Consulting Pty Ltd
16
Risk parameters Any parameter having an impact on the objective (ie life safety or cost) needs to be assessed. Important categories for life safety are: Fire scenarios – fire size, fire location (hard to predict) Fire detection system – detect and warn Fire protection systems – manage and control fire effects Egress provisions – provide safe egress passageway
human behaviour consideration important
© Hyder Consulting Pty Ltd
17
Simple example using event tree 0.985
0.4925
Train fire in tunnel is controlled 0.5
0.5
0.5 0.5
0.00375
Train is brought to station
Fire starts in tunnel 0.015
0.0075
0.5
0.3 0.5
Fire starts in metro network
Train fire in station is controlled by FB 0.00188
Pedestrians evacuate safely 50
Train fire in station is not controlled
Train fire in tunnel is not controlled 1
0.00188
0.00375
Train is not brought to station
0.00113
Pedestrians threatened 50
Train fire in tunnel is controlled by FB 0.7
0.00263
200
Pedestrians evacuate safely 0.8
0.001
0.0005
Station fire is not controlled
© Hyder Consulting Pty Ltd
Pedestrians threatened
0.5
Fire starts in station
complementary events
0.525
0.4995
Station fire is controlled 0.5
0.05625 Pedestrians threatened
Train fire in tunnel is not controlled 0.999
0.09375
0.0004
Train fire in station is controlled by FB 0.2
0.0001
Train fire in station is not controlled
Pedestrians evacuate safely 200
0.02 Pedestrians threatened
END
0.69518
Simple example using event tree 0.985
0.4925
Train fire in tunnel is controlled 0.5
0.5
0.5 0.5
0.00375
Train is brought to station
Fire starts in tunnel 0.015
Train fire in tunnel is not controlled
0.3 0.5
Fire starts in metro network
0.5
0.00188
Pedestrians evacuate safely
0.00375
Train is not brought to station
0.00113
Pedestrians threatened
0.00263
Pedestrians threatened
Pedestrians evacuate safely
0.5 0.8
Fire starts in station 0.001
0.0005
Station fire is not controlled complementary events
© Hyder Consulting Pty Ltd
Pedestrians threatened
0.4995
Station fire is controlled 0.5
0.525
200
Train fire in tunnel is not controlled 0.999
0.05625
50
Train fire in tunnel is controlled by FB 0.7
0.09375
50
Train fire in station is not controlled
0.0075
1
0.00188
Train fire in station is controlled by FB
0.0004
Train fire in station is controlled by FB 0.2
0.0001
Train fire in station is not controlled
Pedestrians evacuate safely 0.02
200
Pedestrians threatened
END
0.695 19
Sub event trees 0.95 1 Fire starts in tunnel
Does not develop or self-extinguishes 0.05
0.05
Tunnel fire sustains development
0.7 Fire controlled by extinguishers 0.3
0.015 Fire is not uncontrolled
= 1 - 0.015 = 0.985 Train fire in tunnel is controlled
0.99 1 Fire starts in station
Does not develop or self-extinguishes 0.01
0.01
Station fire sustains development
0.9 Fire controlled by sprinklers 0.1
0.001
Fire not controlled by sprinklers
© Hyder Consulting Pty Ltd
= 1 - 0.001 = 0.999 Train fire in tunnel is controlled
20
The expected risk
Each unfavourable event has a potential consequence. The consequence is the expected number of
passengers threatened by the fire event. The expected risk of an unfavourable event is: Riskevent = Probabilityevent × Consequenceevent
The expected risk of the scenario is the cumulative sum of all the risks for unfavourable events: ERL = ∑ Riskevent
© Hyder Consulting Pty Ltd
21
Determining Consequences
The consequence of an unfavourable event is
determined by direct computation or modelling For example, to determine the unfavourable event for ‘Train fire in tunnel is not controlled’:
© Hyder Consulting Pty Ltd
A large fire is modelled, say 20MW, using CFD Occupant egress is simulated under untenable conditions Occupants threatened by the effects of high temperatures Occupant movement is limited by reduced visibility
22
Results of CFD simulation – FDS (Fire Dynamics Simulator)
© Hyder Consulting Pty Ltd
Temperature
SECTIONAL VIEW
Visibility
Temperature
PLAN VIEW
Visibility 23
Other CFD models available – Fluent, Solvent (more dedicated to thermal fluid flow)
© Hyder Consulting Pty Ltd
24
Occupant evacuation
Occupant movement speed affected by:
Crowding density Visibility Decision making
Time to exit depends on: texit = tdetect + taware + tresponse + tmovement where tdetect = time to detect and communicate fire cue taware = time occupant becomes aware tresponse = time to respond to cue tmovement = movement time to exit
Simulation models available for simulating occupant behavioural interaction with the environment.
© Hyder Consulting Pty Ltd
25
Sensitivity study Purpose is to:
Assess accuracy of assumptions (eg input values) Identify key factors by varying important parameters
Parameter
Base
Min
END,min
Max
END,max
Fire start in station
0.5
0.1
1.22
0.9
0.171
Tunnel fire does not sustain development
0.95
0.7
4.07
0.99
0.155
Tunnel fire controlled by extinguishers
0.7
0.4
1.37
0.9
0.245
Train fire brought to station
0.5
0.1
1.09
0.9
0.305
Tunnel fire controlled by Fire Brigade
0.3
0.1
0.808
0.8
0.414
Station fire does not sustain development
0.99
0.9
0.875
0.999
0.677
Station fire controlled by automatic sprink.
0.9
0.5
0.775
0.99
0.677
Station fire controlled by Fire Brigade
0.8
0.5
0.725
0.95
0.68
Note: The END for the Base case is 0.695 (values <0.3 and >1.0 are shown in bold)
© Hyder Consulting Pty Ltd
26
Summary
Important aspects of a risk assessment requires a good
understanding of the potential hazards and scenarios Many difficult design parameters can be assessed with a simple risk concept: Risk = Probability × Consequence A sensitivity analysis allows important parameters to be identified and hence used to minimize risk in design Various scenarios can be assessed to determine a cost-effective design solution. This has been demonstrated for assessing fire risks in metro tunnels and stations
© Hyder Consulting Pty Ltd
27
Hyder Consulting Thank you
www.hyderconsulting.com
© Hyder Consulting Pty Ltd
28
The Hong Kong Institution of Engineers, Building Services Division
Hyder Consulting
Presented by:
Dr. Leong Poon Ir. Richard Lau 1 Dec 2005 © Hyder Consulting Pty Ltd
Road tunnels
Sydney Harbour tunnel
Melbourne city link
M5 East tunnel
Cross city tunnel
Western Harbour, HK
Eastern Harbour, HK
© Hyder Consulting Pty Ltd
2
Rail tunnels
Tseung Kwan O Ext., HK New Southern Railway, Sydney Parammatta Rail Link, Sydney GZ Metro
© Hyder Consulting Pty Ltd
West Rail, Mei Foo – Nam Cheong tunnel , HK
3
Stations and platforms, international
Stratford Station Concourse, UK Berlin Hauptbahnhof Station, Germany
Federation Square, Melbourne
© Hyder Consulting Pty Ltd
4
Stations and platforms, East Asia
Guangzhou Line 4 (Huangzhou Station) KCRC West Rail DD400, HK Nam Cheong Station, HK
© Hyder Consulting Pty Ltd
GZ Metro Line 1 Lai King Station, HK
5
Metro Tunnels and Stations – General Characteristics
Limited to metropolitan area (hence the name) Entire network is underground Interspersed by stations every 500 – 800m Predominantly one-way flow (ie single bore)
© Hyder Consulting Pty Ltd
6 Route 8 Cheung Sha Wan to Shatin
Metro Tunnels and Stations – Safety (or risk) characteristics
Traffic is well controlled, hence low accident rates Combustible material is controlled, hence low fire hazard Closely spaced stations allow train to continue to the
station to allow passenger evacuation and fire-fighting Single bore tunnels lack escape passages unlike twin bore tunnels, hence relatively higher risk Large concentration of users, hence any incident places many passengers at risk
© Hyder Consulting Pty Ltd
7 Guangzhou Metro Line 4 - Huangzhou Station Detailed Design
Metro Tunnels and Stations – Objectives (of risk assessment)
Identify relevant fire risks What factors cause incidents/disasters Determine key factors for improving safety Determine recommendations for effective fire protection measures
© Hyder Consulting Pty Ltd
8
Literature Review – Statistics
Cause of fires in metro rails:
Ignition from mechanical/electrical failure, fuel from debris, cabin material & baggage, terrorist activities? Mechanical 13%
Station 17%
Not specified 13% © Hyder Consulting Pty Ltd
Arson 13% Cigarette 10%
Electrical Fault 34%
9
Literature Review – Statistics
Rate of occurrence:
Small rail fire ~ a few a year Severe rail fire ~ 0.5 a year worldwide (Anderson & Paaske)
30 severe incidents 1970-1987
43 fatalities in 5 incidents (King’s Cross = 31)
London underground, July 2005 (terrorist attack)
50 fatalities (> sum of all past records)
Demand for rail metro usage increasing © Hyder Consulting Pty Ltd
Throughput of 26 billion a year Hence potential exposure higher – ie more at risk 10
Literature Review – Fire Hazard
Carriage – main source of fuel + baggage Fire size typically between 6-20 MW Control of lining material will reduce likelihood of fire
development but not necessarily reduce the fire size Terrorist factor ? Significant but highly indeterminate – best handled through a risk assessment approach
© Hyder Consulting Pty Ltd
11
Literature Review – Fire Protection Systems
Purpose is to detect, warn and control For stations, conventional building systems are provided For carriages/tunnels, the following are provided: Detection: – Smoke detectors in air-conditioned carriages – Heat detectors/CCTV may be used in tunnels
Warning:
– Communication systems include break-glass, intercom phone or PA system for staff and passengers
Control:
– Fire suppression systems in engine/equipment areas – Portable systems in passenger area
© Hyder Consulting Pty Ltd
12
Literature Review – Smoke control in tunnels
Smoke control is a key fire protection provision Strategy is to take advantage of longitudinal ventilation Force smoke downstream in the direction of
travel towards the ventilation shaft to be exhausted Passengers take the smoke clear path upstream of air flow Escape stairs may be required for long tunnel sections Escape stairs also used by fire fighters to gain access Train should continue to the next station to facilitate egress and fire-fighting access
© Hyder Consulting Pty Ltd
13
Basic smoke control strategy – Schematics
Direction of longitudinal ventilation Exit
Smoke clear path
Occupant evacuation
© Hyder Consulting Pty Ltd
Downstream
Smoke exhaust
14
Risk assessment concept
Risk is a measure of the consequence of an event, i.e. Risk = Probability × Consequence
Consequence is the estimated measure of the event eg no of fatalities, cost of damage
This is a generic approach – can be readily applied to
assess situations where design is difficult to quantify Life safety and monetary loss usually expressed separately, unless relationship exists, eg 1 fatality = $?????
© Hyder Consulting Pty Ltd
15
Risk assessment application
Main use of risk assessment is as a tool to determine a cost-effective solution by:
Identifying important factors affecting life safety (or cost) Identifying effective protection measures
Effectiveness of each system is measured by its:
Reliability – likelihood of the system operating, and Efficacy – how well it performs its intended function.
A cost-effective solution is the least cost design meeting acceptable level of safety requirements
© Hyder Consulting Pty Ltd
16
Risk parameters Any parameter having an impact on the objective (ie life safety or cost) needs to be assessed. Important categories for life safety are: Fire scenarios – fire size, fire location (hard to predict) Fire detection system – detect and warn Fire protection systems – manage and control fire effects Egress provisions – provide safe egress passageway
human behaviour consideration important
© Hyder Consulting Pty Ltd
17
Simple example using event tree 0.985
0.4925
Train fire in tunnel is controlled 0.5
0.5
0.5 0.5
0.00375
Train is brought to station
Fire starts in tunnel 0.015
0.0075
0.5
0.3 0.5
Fire starts in metro network
Train fire in station is controlled by FB 0.00188
Pedestrians evacuate safely 50
Train fire in station is not controlled
Train fire in tunnel is not controlled 1
0.00188
0.00375
Train is not brought to station
0.00113
Pedestrians threatened 50
Train fire in tunnel is controlled by FB 0.7
0.00263
200
Pedestrians evacuate safely 0.8
0.001
0.0005
Station fire is not controlled
© Hyder Consulting Pty Ltd
Pedestrians threatened
0.5
Fire starts in station
complementary events
0.525
0.4995
Station fire is controlled 0.5
0.05625 Pedestrians threatened
Train fire in tunnel is not controlled 0.999
0.09375
0.0004
Train fire in station is controlled by FB 0.2
0.0001
Train fire in station is not controlled
Pedestrians evacuate safely 200
0.02 Pedestrians threatened
END
0.69518
Simple example using event tree 0.985
0.4925
Train fire in tunnel is controlled 0.5
0.5
0.5 0.5
0.00375
Train is brought to station
Fire starts in tunnel 0.015
Train fire in tunnel is not controlled
0.3 0.5
Fire starts in metro network
0.5
0.00188
Pedestrians evacuate safely
0.00375
Train is not brought to station
0.00113
Pedestrians threatened
0.00263
Pedestrians threatened
Pedestrians evacuate safely
0.5 0.8
Fire starts in station 0.001
0.0005
Station fire is not controlled complementary events
© Hyder Consulting Pty Ltd
Pedestrians threatened
0.4995
Station fire is controlled 0.5
0.525
200
Train fire in tunnel is not controlled 0.999
0.05625
50
Train fire in tunnel is controlled by FB 0.7
0.09375
50
Train fire in station is not controlled
0.0075
1
0.00188
Train fire in station is controlled by FB
0.0004
Train fire in station is controlled by FB 0.2
0.0001
Train fire in station is not controlled
Pedestrians evacuate safely 0.02
200
Pedestrians threatened
END
0.695 19
Sub event trees 0.95 1 Fire starts in tunnel
Does not develop or self-extinguishes 0.05
0.05
Tunnel fire sustains development
0.7 Fire controlled by extinguishers 0.3
0.015 Fire is not uncontrolled
= 1 - 0.015 = 0.985 Train fire in tunnel is controlled
0.99 1 Fire starts in station
Does not develop or self-extinguishes 0.01
0.01
Station fire sustains development
0.9 Fire controlled by sprinklers 0.1
0.001
Fire not controlled by sprinklers
© Hyder Consulting Pty Ltd
= 1 - 0.001 = 0.999 Train fire in tunnel is controlled
20
The expected risk
Each unfavourable event has a potential consequence. The consequence is the expected number of
passengers threatened by the fire event. The expected risk of an unfavourable event is: Riskevent = Probabilityevent × Consequenceevent
The expected risk of the scenario is the cumulative sum of all the risks for unfavourable events: ERL = ∑ Riskevent
© Hyder Consulting Pty Ltd
21
Determining Consequences
The consequence of an unfavourable event is
determined by direct computation or modelling For example, to determine the unfavourable event for ‘Train fire in tunnel is not controlled’:
© Hyder Consulting Pty Ltd
A large fire is modelled, say 20MW, using CFD Occupant egress is simulated under untenable conditions Occupants threatened by the effects of high temperatures Occupant movement is limited by reduced visibility
22
Results of CFD simulation – FDS (Fire Dynamics Simulator)
© Hyder Consulting Pty Ltd
Temperature
SECTIONAL VIEW
Visibility
Temperature
PLAN VIEW
Visibility 23
Other CFD models available – Fluent, Solvent (more dedicated to thermal fluid flow)
© Hyder Consulting Pty Ltd
24
Occupant evacuation
Occupant movement speed affected by:
Crowding density Visibility Decision making
Time to exit depends on: texit = tdetect + taware + tresponse + tmovement where tdetect = time to detect and communicate fire cue taware = time occupant becomes aware tresponse = time to respond to cue tmovement = movement time to exit
Simulation models available for simulating occupant behavioural interaction with the environment.
© Hyder Consulting Pty Ltd
25
Sensitivity study Purpose is to:
Assess accuracy of assumptions (eg input values) Identify key factors by varying important parameters
Parameter
Base
Min
END,min
Max
END,max
Fire start in station
0.5
0.1
1.22
0.9
0.171
Tunnel fire does not sustain development
0.95
0.7
4.07
0.99
0.155
Tunnel fire controlled by extinguishers
0.7
0.4
1.37
0.9
0.245
Train fire brought to station
0.5
0.1
1.09
0.9
0.305
Tunnel fire controlled by Fire Brigade
0.3
0.1
0.808
0.8
0.414
Station fire does not sustain development
0.99
0.9
0.875
0.999
0.677
Station fire controlled by automatic sprink.
0.9
0.5
0.775
0.99
0.677
Station fire controlled by Fire Brigade
0.8
0.5
0.725
0.95
0.68
Note: The END for the Base case is 0.695 (values <0.3 and >1.0 are shown in bold)
© Hyder Consulting Pty Ltd
26
Summary
Important aspects of a risk assessment requires a good
understanding of the potential hazards and scenarios Many difficult design parameters can be assessed with a simple risk concept: Risk = Probability × Consequence A sensitivity analysis allows important parameters to be identified and hence used to minimize risk in design Various scenarios can be assessed to determine a cost-effective design solution. This has been demonstrated for assessing fire risks in metro tunnels and stations
© Hyder Consulting Pty Ltd
27
Hyder Consulting Thank you
www.hyderconsulting.com
© Hyder Consulting Pty Ltd
28
Related Documents
20051201 Fire Risk
October 2019 17
Fire Safety Risk Assesment.docx
May 2020 22
Fire Risk Assessment Proforma
November 2019 15
Fire Explosion Risk
December 2019 16
Fire Risk Zone Mapping
July 2020 13
Prospect Theory Fire Risk Etc.
August 2019 27More Documents from ""
20061103 Tutorship Present Rev6
October 2019 10
20051015 Joint Institutions Forum
October 2019 12
20051104 Hkb Presentation
October 2019 17
20060119 Water Treatment Report
October 2019 12
20051201 Fire Risk
October 2019 17