327985515-helical-staircase.xlsx

  • Uploaded by: Uday Udmale
  • 0
  • 0
  • November 2019
  • PDF

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 327985515-helical-staircase.xlsx as PDF for free.

More details

  • Words: 873
  • Pages: 18
NGASI CONSULTING ENGINEE

P. O BOX 2680 NAIROBI - 00202 TEL: 3860246, 2016972 FA NCCK JUMUIA CONFERENCE CENTRE, L FITNESS CENTRE HELICAL STAIRCASE CALCULATION

REF REINFORCED

Materials

CONCRETE

Concrete

fcu

=

20

N/mm2

DESIGNER'S

Reinforcement

fy

=

500

N/mm2

fyv

=

250

N/mm2

HANDBOOK

( C. E

REYNOLDS & J. C. STEEDMAN)

Cross section Depth of section

h

=

Width of stair

b

=

Cover

=

Diameter of main reinforcement

=

Internal radius, Ri

=

500

mm

External radius, Ro

=

1753

mm

Load Calculation Dead Load Concrete slab, gslab Steps, gsteps

=

h/1000*24

=

170 mm /1000 * 24

g = gslab

+ gsteps

Live Load q=

4

Ultimate Load Case =

1.4 g

+

For helical stair case of

1.200

m

kN/m2 1.6 q

width

W=

m. w

Design Moment, shear and torsion Total angle subtended by helix in plan,

β

Slope of tangent to helix centerline

φ

measured from horizontal Radius of centerline of loading, R1

=

2( Ro3-Ri3) 3( Ro2-Ri2)

Radius of Centerline of steps, R2

b =

=

R1 = R2

8.00

h Chart table

0.5* ( Ro+Ri )

1.10

Parameters

176 k1

=

k2

-0.01

=

Redundant moment acting tangentially at midspan Mo = k1.W.R22 Horizontal redundant force at midspan H = k2.W.R2 Vertical moment at supports Mvs = k3.W.R22 At support

θ=

0.5*β

0.70

NGASI CONSULTING ENGINEE

REF

P. O BOX 2680 NAIROBI - 00202 TEL: 3860246, 2016972 FA NCCK JUMUIA CONFERENCE CENTRE, L FITNESS CENTRE HELICAL STAIRCASE CALCULATION Lateral moment Mn = Mo.Sin(θ).Sin(φ) - H.R2.θ.Tan(φ).Cos(θ).Sin(φ) H.R2.Sin(θ)Cos(φ) + W.R1.Sin(φ).(R1Sin(θ)-R2.θ) Torsional moment T = (Mo.Sin(θ)- H.R2.Cos(θ).Tan(φ) + W.R12Sin(θ) - W.R1.R2.θ).Cos(φ) + H.R2.Sin(θ)Sin(φ) Vertical moment My = Mo.Cos(θ) + (H.R2.θ.Tan(φ).Sin(θ)) - W.R12.(1-Cos(θ)) Thrust N = -H.Sin(θ).Cos(φ) - W.R1.θ.Sin(φ) Lateral shearing force across stair Vn = W.R1.θ.Cos(φ) - H.Sin(θ).Sin(φ) Radial horizontal shearing force Vh = H.Cos(θ)

Design of edge tension reinforcement Design moment

=

Lateral Moment, Mn

�= 𝑀/(𝑓_𝑐𝑢 ℎ 〖� _1 〗 _^2 ) �= �_1 [0.5+ √((0.25− �/0.9) )]

= k

=

�= �_1 [0.5+ √((0.25− �/0.9) )]

Reinforcement

�_(𝑠 )= 𝑀/ (0.95𝑓_𝑦 �)

Provide

z

=

�_𝑠

=

�_(𝑠 𝑝𝑟𝑜𝑣)

3 Y12

=

Design of tension reinforcement Design moment

=

Vertical Moment, My

�= 𝑀/(𝑓_𝑐𝑢 𝑏�_^2 )

k

=

z

=

�_𝑠

=

�= �_1 [0.5+ √((0.25− �/0.9) )]

Reinforcement

�_(𝑠 )= 𝑀/ (0.95𝑓_𝑦 �)

Provide

5 Y10

Distribution reinforcement Provide

Y8 @

=

=

�_(𝑠 𝑝𝑟𝑜𝑣)

=

0.13/10 0 𝑏ℎ

= �_(𝑠 𝑝𝑟𝑜𝑣)

150 mm centers

Shear reinforcement Design shear

=

Lateral shearing force across stair, Vn Average shear stress,

𝑀𝑎𝑥𝑖𝑚𝑢𝑚 (5, 0.8√(𝑓_𝑐𝑢 ))

𝑣= 𝑉_𝑛/𝑏�

Limiting shear =

𝑣_𝑐= 0.79/1.25 × [(100�_𝑝𝑟𝑜𝑣)/𝑏�]^(1/3) × [400/�]^(1/4) ∴

𝑣_𝑙𝑖 𝑚

𝑣_𝑐= 0.79/1.25 × [(100�_𝑝𝑟𝑜𝑣)/𝑏�]^(1/3) × [400/�]^(1/4) ∴

No shear reinforcement required

NGASI CONSULTING ENGINEE

P. O BOX 2680 NAIROBI - 00202 TEL: 3860246, 2016972 FA NCCK JUMUIA CONFERENCE CENTRE, L FITNESS CENTRE HELICAL STAIRCASE CALCULATION

REF

Torsional resistance Design torsion =

Ttor

Check torsion reinforcement

hmin = hmax =

Shear stress induced by torsion

=

𝑣_𝑡 = (2 𝑇_𝑡𝑜𝑟)/( 〖ℎ _𝑚𝑖𝑛 〗 ^2 [ℎ_𝑚𝑎𝑥 − ℎ_𝑚𝑖𝑛/3] )

Limiting torsional shear stress Provide torsional reinforcement Links

6

Distance to center of links Link dimensions Link spacing

=

Torsional resistance

Y10

t=

35

𝑥_1=𝑏−2𝑡

150 mm

𝑇_𝑟=0.8[�_𝑠𝑣/𝑠_𝑣 . 𝑥_1. 𝑦_1. 〖 0.95𝑓 〗 _𝑦𝑣 ]

Check for torsion combined with bending and shear stress v = v t + vf Total shear Limiting shear ∴

=𝑀𝑖𝑛(5 , 0.8√(𝑓_𝑐𝑢 ))

=

3.58

Safe for torsion combined with bending and shear stress

CONSULTING ENGINEERS

202 TEL: 3860246, 2016972 FAX: 2016973 MUIA CONFERENCE CENTRE, LIMURU FITNESS CENTRE HELICAL STAIRCASE CALCULATION

150

mm

1200

mm

25

mm

12

mm

12/303

PAGE

1

DATE

Jun-12

MADE BY

JWM

OUTPUT

d= d1=

kN/m3

=

3.75

kN/m2

kN/m3

=

4.25

kN/m2

=

8

kN/m2

=

17.6

kN/m2

w

JOB NO

119

mm

1169

mm

W

=

21.12

kN/m

=

219

°

=

3.82

rads

=

35.49

°

=

0.62

rads

R1

=

1.24

m

R2

=

1.13

m

k3

=

-0.20

Mo

=

-0.17

kNm

H

=

16.57

kNm

Mo

=

-5.25

kNm

θ

=

1.91

rads

( Ro+Ri )

m

CONSULTING ENGINEERS

202 TEL: 3860246, 2016972 FAX: 2016973 MUIA CONFERENCE CENTRE, LIMURU FITNESS CENTRE HELICAL STAIRCASE CALCULATION

0.01

�_1

12/303

PAGE

2

DATE

Jun-12

MADE BY

JWM

OUTPUT

Mn

=

-24.44 kNm

T

=

-11.18 kNm

My

=

-17.77 kNm

N

=

-41.84 kN

Vn

=

31.77

kN

Vh

=

-5.53

kN

R12Sin(θ) - W.R1.R2.θ).Cos(φ) +

-24.44 kNm

JOB NO

0.95

�_1

46

mm2

339

mm2

�_(𝑠 𝑟𝑎𝑡𝑖𝑜 )

=

0.19 %

�_(𝑠 𝑟𝑎𝑡𝑖𝑜 )

=

0.22 %

-17.77 kNm 0.05

0.94 �_1

�_(𝑠 𝑝𝑟𝑜𝑣)

335

mm2

393

mm2

234

mm2

=

335

mm2

=

31.77

kN

=

0.22

N/mm2

=

5.00

N/mm2

=

0.53

N/mm2

v

<

vc

CONSULTING ENGINEERS

202 TEL: 3860246, 2016972 FAX: 2016973 MUIA CONFERENCE CENTRE, LIMURU FITNESS CENTRE HELICAL STAIRCASE CALCULATION

JOB NO

12/303

PAGE

3

DATE

Jun-12

MADE BY

JWM

OUTPUT

-11.18 kNm 150

mm

1200

mm

𝑇_𝑡𝑜𝑟)/( 〖ℎ _𝑚𝑖𝑛 〗 ^2 − ℎ_𝑚𝑖𝑛/3] )

𝑣 _ 𝑡

𝑣_(𝑡 𝑚𝑖𝑛)

mm mm

Asv

0.86

N/mm2

=

0.40

N/mm2

=

471 mm2

𝑦_1=ℎ−2𝑡 𝑇_𝑟 =

v= 3.58

=

N/mm2

ned with bending and shear stress

54 kNm

1.09

N/mm2

vt

>

vtmin

x1

=

1130

mm

y1

=

80

mm

More Documents from "Uday Udmale"

Cpe 41450.pdf
April 2020 4
Staircase Drg.pdf
November 2019 19
Staircase Model 2.pdf
November 2019 19
Staircase Drg.pdf
November 2019 18