Up-Down Stand Design

8/13/2019 Up-Down Stand Design

1/23

S.NO. Page

No

1 Introduction

2 Estimation of Seismic Coefficent

3 Summary of Bearing Reactions

4 Design of End Diapghragm for Longitudinal

Seismic Forces

5 Design of Shear Key For Longitudinal

Seismic Forces

6 Design of Shear Key For Transverse

Seismic Forces

Appendix -A Analysisis of Precast Girder

Appendix -B Grillage Analysisis of Deck

For SIDL

Appendix -C Grillage Analysisis of Deck

For Live Load

Design of Diaphragms and Seismic Restrainer for bridge at ch. 55.460

Contents

ITEM

(Span Arrangement 27.59 m c/c Bearing)


2/23

1.0 Introduction

This note presents the detailed design of diaphrams and Seismc restrainer for

bridge at ch 55.460 on proposed Rajkot-Jamnagar-Vadinar in Gujrat. The

bridge is 3 lane with a deck width of 12.0m and carriageway width of 8.75 m

with safe kerb and footpath.The supersrtuctrue comprises of Precast Post

Tensioned Beams with cast in situ deck slab on Elastomeric Bearings. The

Elastomeric bearings are primarily designed to cater for reactions and rotations

due to vertical loads and translations due to temeprature, shrinkage, creep and

elastic shortening.The seismic and braking forces are to be transferred through

concrete shear keyi.e. an upsatnad from pier cap. Under lonfgitudinal seismic

condition, the upstand transfers the loangitunal forces by abuting against End

Diapghragms of superstructure.


3/23

2.0 Estimation of Seismic coefficient

Horizontal Seismic Coefficient ( cl 222.5 of IRC:6-2000)

h =

For Zone IV, Z = 0.24 ( Table 5 of IRC:6-2000)

Sa/g = 2.5 ( Fig 12 5 of IRC:6-2000)

R = 2.5

I = 1.5 (For Important Bridge)

Substituting for above values , we get

h = 0.18

Vertical Seismic Coeffic ient ( cl 222.3 of IRC:6-2000)

v = 0 5 h= 0.09

Considering the bridge location and the Seismic Zoning map of India as per Fig

11 of IRC:6-2200, the bridge is likely to fall in the boundary of zone

demarcation line between Zone III and Zane IV and therefore the higher zone

i.e. Zone IV has been considered for design and detailing.

(Z/2). ( Sa/g)

(R/I)


4/23

3.0 Estimation of Bearing reactions

The summary of Bearings reactions are presnted in the subsequent sheets

The Dead Laod reactios i.e. weight of Precast girder and , deck slab are

obtained by analysis of Precast Girder ( Appendix A) and whereas those due to

SIDL and live laod are obtained by Grillage Analysis (Refer appendix B and

Appendix C)


5/23

3.1 Synopsis of Bearing Reaction due to Dead Load & SIDL

27 m c/c EJ

26 m

3.00 m

1.5 m

C/L of Bridge

1.5 m

3.00 m

Fig. 6.1 Bearing Node Numbering

(Not to Scale)

Load Load Support Node Force-Y Total Total Support Node

Case List No. (t) V (t) MT (tm) No.

A 102 31.43 4.500 141.44 A 102

302 31.43 1.500 47.15 302

Distance

from C/L of

Bridge (m)

Associ ated

MT (tm)

cast

102

302

A

502

702

112

312

B

512

712

502 31.43 -1.500 -47.15 502

702 31.43 -4.500 -141.44 125.72 0.00 702

B 112 31.43 4.500 141.44 B 112

312 31.43 1.500 47.15 312

512 31.43 -1.500 -47.15 512

712 31.43 -4.500 -141.44 125.72 0.00 712

A 102 24.10 4.500 108.45 A 102

302 24.10 1.500 36.15 302

502 24.10 -1.500 -36.15 502

702 24.10 -4.500 -108.45 96.40 0.00 702

B 112 24.10 4.500 108.45 B 112312 24.10 1.500 36.15 312

512 24.10 -1.500 -36.15 512

712 24.10 -4.500 -108.45 96.40 0.00 712

A 102 55.53 4.500 249.89 A 102

302 55.53 1.500 83.30 302

502 55.53 -1.500 -83.30 502

702 55.53 -4.500 -249.89 222.12 0.00 702

B 112 55.53 4.500 249.89 B 112

312 55.53 1.500 83.30 312

512 55.53 -1.500 -83.30 512

712 55.53 -4.500 -249.89 222.12 0.00 712

A 102 18.92 4.500 85.14 A 102

302 6.70 1.500 10.05 302

502 6.70 -1.500 -10.05 502

702 18.92 -4.500 -85.14 51.24 0.00 702

B 112 18.92 4.500 85.14 B 112

312 6.70 1.500 10.05 312

512 6.70 -1.500 -10.05 512

712 18.92 -4.500 -85.14 51.24 0.00 712A 102 74.45 4.500 335.03 A 102

302 62.23 1.500 93.35 302

502 62.23 -1.500 -93.35 502

702 74.45 -4.500 -335.03 273.36 0.00 702

B 112 74.45 4.500 335.03 B 112

312 62.23 1.500 93.35 312

512 62.23 -1.500 -93.35 512

712 74.45 -4.500 -335.03 273.36 0.00 712

DeadLoad(Pre

Girder)

TOTALDEADLOAD

TOTALDEADLOAD+

SIDL

1SIDL

DeadLoad(Deck

S

lab)


6/23

3.2 Synopsis of Bearing Reaction due to Live Load (with Impact)

27.59 m c/c EJ

26 m

3.00 m

1.5 m

C/L of Bridge

1.5 m

3.00 m


(Not to Scale)

NODE Load LOAD Support Node Force-Y Total Total

List CASE No. (t) V (t) MT (tm)

A 102 44.27 4.500 199.22s . 2 D

Distance

from C/L of

Brid e m

Ass ociated

MT (tm)

102

302

A

502

702

112

312

B

512

712

302 48.53 1.500 72.80

502 3.57 -1.500 -5.36

702 -1.83 -4.500 8.24 94.54 274.89

B 112 10.81 4.500 48.65

312 5.85 1.500 8.78

512 4.04 -1.500 -6.06

712 -1.15 -4.500 5.18 19.55 56.54

Load Load LOAD Support Node Force-Y Total Total

Case List CASE No. (t) V (t) MT (tm)A 102 16.96 4.500 76.32

302 59.84 1.500 89.76

502 18.54 -1.500 -27.81

702 -0.81 -4.500 3.65 94.53 141.92

B 112 7.70 4.500 34.65

312 5.43 1.500 8.15

512 5.10 -1.500 -7.65

712 1.32 -4.500 -5.94 19.55 29.21


Case List CASE No. (t) V (t) MT (tm)

A 102 41.63 4.500 187.34

302 37.69 1.500 56.54

502 15.16 -1.500 -22.74

702 -1.50 -4.500 6.75 92.98 227.88B 112 10.48 4.500 47.16

312 6.60 1.500 9.90

512 4.23 -1.500 -6.35

712 -0.21 -4.500 0.95 21.10 51.66

LiveLoadReaction

coexistentwithMa

ReactionatNode3

atSupportA

34

Distance

from C/L of

Ass ociated

MT (tm)

70RWHEELPLACE

MOST

ECCENTRICALLY

LiveLoadR

eactions

coexistentw

ithMax.

ReactionatNode302

atSupportA

230

CLASSA2LANE

PLACEDMOST

ECCENTRICALLY

LiveLoadReactions

coexistentwithMax.

ReactionatNode302at

SupportA

133

Distance

from C/L of

Ass ociated

MT (tm)

70RWHEELPLACED

CENTRALLYIN

CARRIAGEWAY


7/23


27.59 m c/c EJ

26 m

3.00 m

1.5 m

C/L of Bridge

1.5 m

3.00 m


(Not to Scale)

102

302

A

502

702

112

312

B

512

712



A 102 26.29 4.500 118.31

302 40.98 1.500 61.47ctions

Max.

de302

A ANE

ALLY

WAY

Distance

from C/L of

Ass ociated

MT (tm)

. - . - .

702 0.54 -4.500 -2.43 92.99 139.58

B 112 8.10 4.500 36.45

312 6.42 1.500 9.63

512 5.02 -1.500 -7.53

712 1.56 -4.500 -7.02 21.10 31.53



A 102 41.01 4.500 184.55

302 38.69 1.500 58.04

502 41.32 -1.500 -61.98

702 18.45 -4.500 -83.03 139.47 97.58

B 112 9.92 4.500 44.64

312 8.84 1.500 13.26

512 7.43 -1.500 -11.15

712 5.46 -4.500 -24.57 31.65 22.19



A 102 28.96 4.500 130.32

302 40.78 1.500 61.17

502 40.78 -1.500 -61.17

702 28.96 -4.500 -130.32 139.48 0.00

B 112 7.66 4.500 34.47

312 8.16 1.500 12.24

512 8.16 -1.500 -12.24712 7.66 -4.500 -34.47 31.64 0.00

Distance

from C/L of

Ass ociated

MT (tm)

Live

LoadReactions

coexistentwithMax.

ReactionatNode302

atSupportA

527

CL

ASSA3LANE

PLACEDCENTRALLY

INCARRIAGEWAY

LiveLoadRea

coexistentwit

ReactionatNo

atSupport

329

CLASSA2L

PLACEDCENT

INCARRIAGE

Distance

from C/L of

Ass ociated

MT (tm)

LiveLoadReactions

coexistentwithMa

x.

ReactionatNode5

02

atSupportA

428

CLASSA3LANE

PLACEDMOST

ECCENTRICALLY


8/23


9/23


27.59 m c/c EJ

26 m

3.00 m

1.5 m

C/L of Bridge

1.5 m

3.00 m


(Not to Scale)

102

302

A

502

702

112

312

B

512

712



A 102 37.35 4.500 168.08

302 9.14 1.500 13.71ctions

Max.

de702

B ANE

ST

LLY

LLY

Distance

from C/L of

Ass ociated

MT (tm)

. - . - .

702 37.35 -4.500 -168.08 92.98 0.00

B 112 5.97 4.500 26.87

312 4.58 1.500 6.87

512 4.58 -1.500 -6.87

712 5.97 -4.500 -26.87 21.10 0.00LiveLoadRea

coexistentwit

ReactionatNo

atSupport

923

CLASSA2L

PLACEDM

ECCENTRIC

BUT

SYMMETRIC


10/23

4 Sumamry of Bm & Shear Force

The Diaphrgam, down stand and support at top of shear key is modeled in STAAD.

The summary of BM 7 Shear forces are given as hereunder:-

4.1 Sumamry of Design BM & Shear Forces for Horizontal Bending

Beam L/C Node Fx Mton Fy Mton Fz Mton Mx MTon- My MTon- Mz MTon-

Max Fx 6007 1 7 0 0 11.773 0.791 19.52 0

Min Fx 6007 1 7 0 0 11.773 0.791 19.52 0

Max Fy 6007 1 7 0 0 11.773 0.791 19.52 0

Min Fy 6007 1 7 0 0 11.773 0.791 19.52 0

Max Fz 6007 1 7 0 0 11.773 0.791 19.52 0

Min Fz 6035 1 83 0 0 6.618 0.365 14.52 0

Max Mx 6007 1 7 0 0 11.773 0.791 26.80 0

Min Mx 6070 1 178 0 0 8.93 0.24 12.46 0

Max My 6007 1 8 0 0 11.773 0.791 26.80 0

Min My 6070 1 178 0 0 8.93 0.24 12.46 0

Max Mz 6007 1 7 0 0 11.773 0.791 19.52 0Min Mz 6007 1 7 0 0 11.773 0.791 19.52 0

Max 11.773 26.8

Spacing between horizontal members = 0.19 m

Design BM for Plan bending = 26.8

0.19

Design BM for Plan bending = 141 tm per m

Design BM for Plan Shear = 11.773

0.19

Design SF for Plan bending = 62 t per m

4.2 Sumamry of Design BM & Shear Forces for Vertical Bending

Beam L/C Node Fx Mton Fy Mton Fz Mton x MTon- y MTon- Mz MTon-m

Max Fx 181 1 111 0 0 22 -0.043 15.19 0

Min Fx 181 1 111 0 0 18.39 -0.043 15.19 0

Max Fy 181 1 111 0 0 18.39 -0.043 15.19 0

Min Fy 181 1 111 0 0 18.39 -0.043 15.19 0

Max 22 15.19

Spacing between Vertical members = 0.1175 m

Design BM for Vertical Bending = 15.19

0.1175

Design BM for Vertical bending = 129 tm per m

Design BM for Vertical Shear = 22

0.1175

Design SF for Vertocal bending = 187 t per m


11/23

4.0 Design of End Diaphragm for Longitudinal Seismic Forces

The Longitudinal Seismic Forces are considered due to Dead load and SID only and seismic forces due to live shall not be considered as

er clause 222.7 of IRC:6-2000

Total Dead Load = 2 x 222.12 = 444.25 t

(Sum of DL Reactions for Four Bearings)

Total SIDL = 2 x 51.24 = 102.48 t

(Sum of SIDL Reactions for Four Bearings)

Longitudinal Seismic Force due to DL = 0.18 x 444.25 = 79.96 t

= =

.

. .

Total Longitudinal Seismic Force = 79.96 + 18.45 = 98.41 t

Say 99.00 t

As per cl 222.11 of IRC:6-2000, the reaction blocks should be designed for twice the seismic forces.

Design Seismic Force = 2 x 99.00 = 198.00 t

No of Longitudinal girder = = 4

Shear Force = = 99.00 t

Design of Diaphragm at Section 'B" :

owever as t e se sm c restra ners are es gne to prevent s o gement o superstructure

The in plane stiffness of deck slab is very high and the distribution of longitudinal seismic forces may be uniform among precast girders.

The BM cause plan bending of diaphragm.

Thickness of Diaphragm D = = 0.60 m

Effective cover = = 0.07 m

Effective depth d = = 0.53 m

Depth of Diaphragm b = = 1.74 m


12/23


13/23

For M 45 Grade Concrete End Diaphragm at

fck = 45 MPa

fy = 400 MPa

As per IS:456-2000,

Moment of Resistance w.r.t. concrete

MuR = 0.36.fck.b.xu(d-0.416xu)

Where xumax/d = 0.48

=umax .

MuR = 270 tm

> 222.75 tm OK

Proposed tensile Reinforcement on vertical Face of Diaphragm

As = 11 Nos Tor 32 + 11 Nos Tor 25

As = 14246 mm pt = 1.74 %

Actual xu = 0.87 fy As

. . c . .

= 4957725.38

25168.05= 197 mm

< xumax

Therefore section is Under reinforced, and Moment of Resistance is given by

MuR = 0.87fy.As(d-0.42.xu)

= 222 tm

> 222.75 tm OK

Check for Shear

Max. Shear Force = 99 x 1.00E+04

V = 9.90E+05 N

Shear stress = 9.90E+051545 x 530

= 1.21 MPa

< 3.9 MPa O.K

For pt= 1.5 % ( Taken on lower side)

Tc < 0.792 MPa

Vs = 9.90E+05 -0.792 x 1545 x 530

= 3.41E+05 N

Shear Reinforcement

Adopting spacing s = 200 mm

Asv = 3.41E+05 x 200

0.87 x 400 x 530

= 370 mm

Min Asv = 0.4 x 1545 x 200

0.87 x 400

= 355 mm (Governing)

Provide 4-Legged stirrups of 12 mm dia @ 200 mm c/c

Asv = 452 mm > 355 mm


14/23

5.2 Design of Diaphragm for Vertical Bending & Shear

For M 45 Grade Concrete End Diaphragm at

The BM cause plan bending of diaphragm.

Thickness of Diaphragm D = 0.60 m

Assuming 70 mm rff cover d = 0.53 mLength of Diaphragm, b = 1 m

fck = 45 MPa

As per IS:456-2000,

Moment of Resistance w.r.t. concrete

MuR = 0.36.fck.b.xu(d-0.416xu)

Where x d = 270 0848umax .

xumax = 143.1449 m

MuR = 175 tm per m

> 129 tm per m OK

Proposed tensile Reinforcement on vertical Face of Diaphragm

As = 10 Nos Tor 32 + 0 Nos Tor 32

As = 8042 mm2

t = 1.52 %

Actual xu = 0.87 fy As

0.362.fck.b.

= 3498478

16290

= 215 mm< xumax

Therefore section is Under reinforced, and Moment of Resistance is given by

MuR = 0.87fy.As(d-0.42.xu)

= 154 tm

> 129 tm OK

5.1.1 Check for Shear

V = 1.9E+06 N

Shear stress =

1000 x 530

= 3.53 MPa

< 3.9 MPa O.K

1.87E+06

For pt= 1.5 % ( Taken on lower side)

Tc < 0.792 MPa

Vs = 1.9E+06 -0.792 x 1000 x 530

= 1.5E+06 N


15/23

Shear Reinforcement

Adopting spacing s = 100 mm

Asv = 1.5E+06 x 100

0.87 x 415 x 530

= 759 mm2

Provide 6-Legged stirrups of 16 mm dia @ 100 mm c/c

=2

>

759 mm2

O.K


16/23

5.0 Design of Longitudinal Sesmic Restrainer

Shear key is designed as a corbel to cater for the longitudinal forces from End diaphragm.

Reference: "Practical Design against Shear & Torsion and Design of of Short Cantilevers and Deep Beams" from

"Concrete Bridge Practice-Analysis , Design and Economic" by Dr. V. K Raina

Hus

Longitudinal Seismic Restrainer

Vu

Longitudinal/Traffic Direction

a

Pier Cap Top Level

d'

h

Vu = 198 t (After multiplying by 2)

Hu = 0 t

h = 500 mm

s = 500 mm

b = 2400 mm

a = 225 mm

fck = 45 MPa

fsy = 500 MPa (For main reinforcement calculations) 80% OF PERMISSIBLE S

fsy = 415 MPa (For shear reinforcement calculations)

= 1.4 (For Concrete placed monol ithical ly across interface)

p = 150 mm ( Pitch of Horizontal stuirrups)

fc' = 0.8 x 45

= 36 MPa

Eff cover = 80 mm

d' = 500 -80

= 420 mm

Step-1: Ensure s/d' > 0.5

s/d' = 500 / 420 = 1.19

> 0.50 OK

Step-2: Ensure Vu/(bd) < 0.15 fc'

d = 0.8 d' = 336 mm

0.15 fc' = 0.15 x 360 = 54.0 kg/cm 2

Shear Stress = Vu / bd

= 198000 / 8064 = 24.55 kg/cm^2

< 54.0 OK

Step-3: Calculate Shear Friction Reinforcement : Avf

Avf = Vu / 0.85.fsy.

= 198000 / 5950 = 33.28 cm 2


17/23

Step-4: Calculate Direct Tension Reinforcement : At

Hu < 0.2 Vu = 39.6 t

At = Hu / 0.85.fsy

= 39600 / 4250 = 9.32 cm^2

Step-5: Calculate Flexure Tension Reinforcement : Af

Af = Vu.a+Hu.(h-d') / 0.85.fsy.d

= 4771800 / 142800 = 33.42 cm 2

Step-6: Compute Total Primary Reinforcement : As

As 6.35 cm^2 OK

Min. Development Length= 50 x 10

= 500 mm

in each of 6 165mm c/c

Step 8 Provide Horizontal Stirrups, Av

Av = / fsy.d

Vc = 10.b.d. kg = 106464 kg

Av = 0.05837 cm 2

Provide 2 L-10mm Horizontal Planes spaced at

for full height of shear key.

in each of 5 296mm c/c

0.50 ( Vu-Vc).p

Ah Provided = 7.85 cm^2

> 0.06 cm^2 OK


21/23

6.0 Design of Pedastal for Transverse Sesmic Forces

Downstand from diphragm is designed to as a corbel to cater for the Transverse forces from Superstructure

Transverse Direction

Hu

s

Bearing

a

Vu Downstand from Diaphragm acts

as Tranvserse Stopeer against Pedestal

Pier Cap Top Level d'

d'

C/c distance between girders = 3000 mm

Dimension of Pedestal in transverse direction = 700 mmDimension of Pedestal in Longitudinal direction = 600 mm

Depth of Pedestal at G3 (On conservative side) = 550 mm

Thickness of Bearing = 80 mm

Depth of bottom rectangular & traingular haunch = 360 mm

Gra e o concrete o Diap ragm = 40 Mpa

Grade of Steel = 500 Mpa

Vertical Loads of One Span:

Total DL = = 444.2 t

Total SIDL = = 102.5 t

Total Live Load = = 83.1 t

( 50% of (3 x 55.4) t for 3 Lanes of Class "A")

Transverse Seismic Force due toDL = 0.18 x 444 = 79.96 t

SIDL = 0.18 x 102 = 18.45 t

50% Live Load = 0.18 x 83 = 14.96 t

113.37 t

The above forces is to be shared by two end end diaphragms of a span.

Transverse seismic Force at each end of Diaphragm

HT = 56.68452 t

Vu = 113.36904 t (After multiplying by 2)

Hu = 0 t

h = 700 mm

s = 700 mm

b = 600 mm

a = 275 mm (Acting at half the depth of pedestal from top of pier cap)

Cover = 80 mm

fck = 40 MPa

fsy = 500 MPa

= 1.4 (For Concrete placed monolithically across interface)

p = 150 mm ( Pitch of Horizontal stuirrups)


22/23

fc' = 0.8 x 40 = 32.00 MPa

d' = 700 -80 = 620 mm

Step-1: Ensure s/d' > 0.5

s/d' = 700 / 620 = 1.13

> 0.5 OK

Step-2: Ensure Vu/(bd) < 0.15 fc'

d = 0.8 d' = 496 mm.

0.15 fc' = = 48.0 kg/cm 2

Shear Stress = Vu / bd

= 113369 / 3720 = 30.48 kg/cm 2

< 48.0 OK

Step-3: Calculate Shear Friction Reinforcement : Avf

= . . .

= 113369.04 / 5950 = 19.05 cm 2

Step-4: Calculate Direct Tension Reinforcement: At

Hu < 0.2 Vu

= 22.673808 t

At = Hu / 0.85.fsy

= 22673.808 / 4250 = 5.34 cm^2

Step-5: Calculate Flexure Tension Reinforcement: Af

Af =

= 3299039.1 / 210800 = 15.65 cm 2

Step-6: Compute Total Primary Reinforcement: As

As

Date post:	04-Jun-2018
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