Suhas P Khedkar

Hindustan Construction Co Ltd

28 May 2012 Presetation to 3rd annual Bridges India Summit 2012 2

Erecting Long Span Briges to suit Indian Conditions and Requirements

Presentation by

Suhas P Khedkar

(AVP- Engineering,) Hindustan Construction Company

To 3rd Annual Bridges India Summit 2012

On 17th May 2012


Table of Contents

Different Methods of erection of Superstructure

Cast in Situ Construction

Comparison of Conventional and Cantilever Construction Method

Innovative Construction of III rd Godavari Railway Bridge at Rajamahendri

Bandra Worli Sea Link – Superstructure Construction entirely by Precast segmental Construction.

Segment Casting and Erection of Appraoch Spans

Specaial Challenge during Construction- Relocation of LG

Construction of Cable stayed bridge

Conclusions

Different Methods of Erection of Superstructure


Different methods of Superstructure Erection

• Cast in situ construction

1. Conventional method for normal spans by use of staging

2. Using specialized technology for longer span bridges:

• e.g.. Use of centering girders,

• and bridge builders for cantilevering superstructures

• Construction using Precast elements

• Construction using precast girders of entire length,

• Construction using precast segments to be assembled during erection to form

girders of complete length

• Special techniques like Incremental launching method


Different methods of Superstructure Erection

• Method of Erection of Superstructure is site specific. And also design specific.

• In fact design should suit the method of erection dictated by site conditions and other constraints

• Final Choice is to be made from cost considerations. Evaluation of a couple of alternatives is many times necessary for major projects to decide cost effectiveness.

Cast in Situ Construction


Cast in Situ Construction for Superstructure

• Conventional casting on staging

• Method suitable for normal spans

1. More suitable for normal span viaducts as staging can be supported on ground

2. Has been used for both I girders and Box Girders.

3. If number of spans are small , use of precast girders and launching system is not cost effective

4. For box girders conventional casting can not be avoided as launching system may not be feasible due to excessive weight of span.



• Conventional casting on staging of long span superstructure is generally not feasible beyond about 50 m span due to

– excessive weight,

– Large quantity of staging and

– increased cycle time and concrete pour size.

– Especially difficult for River Bridges as staging needs to be supported on temporary piles.



• Cast in Situ Cantilever Segmental Technique

.



• Cast in Situ Cantilever Segmental Technique

Method suitable for long span box girders. Advantages as follows:

1. Each stage of construction is self supporting after completion. The erection system or the bridge builder can be erected on the tip of units cast earlier.

2. Construction is done in segments of convenient length, so that formwork and bridge builder frames supporting the formwork can be optimally

designed.

3. Construction progresses from pier in both directions towards centre of span. This allows maintaining feed lines for concrete and access for men

and material from the pier location up to the working point.


Conventional Casting Vs Cantilever Construction

Comparison of two methods:

• Yamuna bridge at Naini Allahabad – 60 m spans Cast in Situ on Conventional staging

Elaborate staging arrangement needed for the span at 20 m from water level

• Bridge over River Brahmaputra at Tezpur

• Compare the small Bridge Builder on the tip of the cantilever with the staging of Naini Bridge



Yamuna Bridge Staging – Elevation and Side View



Tezpur Bridge Bridge Builder – Elevation and Side View


Cast in Situ Cantilever Construction for Long Span River Bridges

Tezpur Bridge over River Brahmaputra – Different spans in different stages of construction



Ganga Bridge at Varanasi - Bridge Builder in Elevation and Side View



Ganga Bridge at Varanasi – after Completion

Innovative Construction for III Godavari Railway Bridge at Rajamahendri


Innovative Construction for III Godavari Bridge Superstructure

III Godavari Railway Bridge

28 spans of 98 m each – 94 m C/C of bearings



• III Godavari Railway Bridge near Rajamahendri has been constructed using an innovative technique.

• The design itself was developed for the innovative erection technique, under typical constraints posed in the tender specifications.

• The foundations and substructure was designed to suit standard railway span of 94.0 m using steel girders.

• The tender for superstructure invited alternatives with prestressed concrete (PSC) superstructure.

• Challenge to design a PSC superstructure within the design capacity of the substructure and foundations, which were designed and constructed for the lighter loads of the steel superstructure.

• A bow string girder design was proposed by HCC.



Salient Features:

1. Structural System – Bow String Girder in Prestressed Concrete

2. Span of Girder: 94.0 m

3. Arches in Reinforced concrete Constructed using Cast in situ segmental technique

4. Suspenders in High tensile Steel – BBR Dyna hangars

5. Tie Girder in Prestressed Concrete – Box shaped



Innovative Features:

1. Top down Construction – Arch was constructed first

2. Tie girder constructed using formwork supported on suspenders

3. Arch was constructed using cast in situ cantilevering segmental technique in 7 stages

4. Arches from the two piers progressed to meet at the midspan, connected by a closure pour



Stages of Construction of Arch:

1. Erect central tower

2. Cast starting stubs

3. Erect formwork for typical segment supported by stay cables

4. Cast first segment

5. Repeat stages 3 and 4 for balance 6 segments

6. Erect formwork for closure pour on the last segment at crown

7. Cast closure pour



Stage 1 Cast starting stubs Stage 2 Erect Formwork for first

segment on starting stubs



Itermediate Stage: Formwork supported on completed arch ready to receive for concrete for the next segment



Itermediate Stage: Formwork supported on completed arch ready to receive for concrete for the next segment



Closure Pour: Formwork supported on the last segment of 1/2 arch



Arches for various spans completed



Construction of Tie Girder



Completed Bridge

Bandra Worli Sea Link Project Superstructure Construction entirely by Precast Segmental Technique, for both Cable Stayed and Approach Spans.


Bandra Worli Sea Link Project – special Features • First Sea Link in India and with

Precast Segmental construction

• The entire sea link, including the cable stayed bridges has been constructed using precast segments for the superstructure.


Bandra Worli Sea Link Project – special Features Many Firsts in our country

• First Cable Stayed Bridge across sea: India’s first open sea and longest cable stayed bridge.

• First Cable Stayed Bridge with a Single Central Pylon.


Bandra Worli Sea Link Project – special Features Many Firsts in our country

• The entire sea link, including the cable stayed bridges has been constructed using precast segments for the superstructure. Total 2342 segments have been cast and used.

• The precast segments used for this sea link are one of the widest and heaviest in our country; - 18.1 m & 20 m in width , weight 120 to 140 MT

•Needing a very large casting yard with short line casting cells, large capacity gantries, matching capacity multi axle trailer for segment transportation, and specially designed gantries for segment erection.


Special Features of the Project

Engagement of Asian Hercules, one of the largest floating shear leg crane in the world for shifting 1260 MT launching truss from Bandra end to Worli end of the main cable stay bridge

Up to 25-m high piers in open sea, giving ample headroom to marine traffic

Use of Politron Disc bearings for the first time in India

Piling through rocks exceeding 120 Mpa crushing strength

Use of Automatic Climbing Formwork for Pylon Construction


Bandra Worli Sea Link Salient Design Features • Precast Segmental superstrucure except KAGK Link Bridge • Aesthetically pleasing deck profile, with uniform depth for all

bridges - Bandra approach , Bandra Cable Stayed, Worli Cable Stayed, Worli Approach.

• Unique Design of Bandra Cable Stayed - 250 m spans on either side , supported on a Central Pylon,

A1

P19

P19

A1 P17

16x50 = 800m

600mBANDRA CABLE STAY

4X50=200m(SPAN-BY-SPAN)

350mWORLI CABLE STAY

28X50 = 1400mPRECAST SEGMENTAL (SPAN-BY-SPAN)

P6 P12

500mPRECAST SEGMENTAL

(BALANCED CANTILEVER) 150mPRECAST SEGMENTAL

(FORWARD CANTILEVER)

PRECAST SEGMENTAL

BANDRA CABLE STAY600m

WORLI CABLE STAY350m

NORTH 800m

NORTH APPROACH BRIDGE SOUTH APPROACH BRIDGE

BANDRA

WORLI

APPROACH ROAD

546m

APPROACHBRIDGE

& TOLL PLAZABANDRA

WORLI

200mSOUTH APPROACH BRIDGE

1400m

LIN

K BR

IDG

E81

1m

(SPAN-BY-SPAN)

Bandra Worli Sea Link Project Segment Casting and Erection


Casting Yard and Erection Gantry at BWSLP The project needed a very large casting yard, and two specially designed LGs, which needed to to be supplemented by one more LG from Worli end in the last season.


Advantages of Precast Superstructure Vs Cast in Situ

• Construction of Superstructure in parallel with Foundation construction.

• When Foundations are being constructed at various site locations, superstructure elements can be precast in a separate casting facility.

• Advantages of factory production, with ease in quality control, and dimensional accuracy, due to easy acces, and dedictaed equipment, and survey stations.

• Good quality control due to planned facilities like proper curing arrangement, dedicated supervision.

• The above are relatively much difficult at actual site locations due to difficult access, great heights and different locations.


Principles of Precast Segmental Construction

• Span is divided into a number of segments of full deck width

• The segments are match cast to attain the final geometry as of the erected span.

• Match casting and geometric control are of great importance as the bridge is virtually built in the casting yard. Any error in match casting will be difficult to correct during erection, as the span will not fit on the piers.

• Precision Survey in casting yard to attain desired geometry

• Precast Segmental Construction offers use of industrialized, repetitive construction procedures, which contribute to improved quality control as well as reduction in construction time .


Importance of Precision in Precast Segmental Construction

• Span is divided into a number of segments which are match cast to attain the final geometry as of the erected span.

• The bridge is virtually built in the casting yard. Any error in match casting will be difficult to correct during erection, as the span will not fit on the piers.

• The bridge has both vertical gradient, and Horizontal curvature.

• The bridge deck therefore follows a space curve.

Precast Segmental Construction for Bandra Worli Sea Link Project, Mumbai – CEMCON 2007

February, 23 - 2007 Page 42

SEGMENT : MATCH CASTING


Planning and Management for Casting Yard

(LONGITUDINAL DIRECTION)TYPICAL CROSS SECTION AT SEGMENT STORAGE AREA

(TRANSVERSE DIRECTION)TYPICAL CROSS SECTION AT CASTING CELL AND STORAGE AREA

(STORAGE BAY 1) (STORAGE BAY 2)

(REBAR JIGS)

CASTING YARD & STACKING YARD CROSS-SECTION

(CASTING CELL)


Precasting Yard at BWSLP- Capacity to stack 400 segments. And 9 casting cells.


Prefab Reinforcement Cage handling


Match casting at Precasting Yard


Precast Segment Pour Sequence

3.17 CUM

1.26 CUM

1.26 CUM

2.52 CUM2.19 CUM2.69 CUM4.28 CUM

1.66 CUM

1.66 CUM

7 89

2.52 CUM 2.19 CUM 2.69 CUM

2

3

45

3.17 CUM

1.26 CUM

1.26 CUM 1.66 CUM

1.66 CUM6

CONCRETE PLACING SEQUENCETOTAL CONCRETE QUANTITY = 44.30 CUM

12a

3a

4a 5a

6a

7a8a 9a10

5.33 CUM


Segment Handling at Precast Yard


Segment Transportation on Special Trailer


Main Truss

Front Leg

Suspension Frames

Rear Leg

Rear Pylon

Front Pylon

Center Leg

Connection Beam

Rear Trolley

Front Trolley

Launching Girder at BWSLP


Segment Transportation in Sea on Barge

Main Challenge During Construction of Approach Span: Relocation of LG from Bandra Approach spans beyond Bandra Cable Stayed bridge: Shifting by 500 m in the sea.

Text (Font Arial 16, Color Black, Line Spacing 30 points).





Need for Relocation




Relocation of Launching Trusses using 1600 MT capacity Barge Mounted Crane – Asian Hercules





Entire LG weighing 1260 MT , of length 105 m was physically lifted and shifted from P17-P18 to P20-P21

Construction of Cable Stayed bridge


Need for detailed Construction Stage Analysis


Results of stage-by-stage Analysis

Stage-by-Stage Analysis

Tower Construction Deck Erection

Precamber Values Fibre Stresses

Strutting Requirements and Force Levels Casting Curve, Erection Curve and Control Lines

Stay Cable Forces for Installation, Tensioning and fine tuning Forces

Stage Deformations

Temporary PT


Casting Curve


Stage by Stage Deck Camber Curves Deck Camber Curves for Bandra Bridge Stage by Stage

-100-90-80-70-60-50-40-30-20-10

0102030405060708090

100110120130140150160170180190200210220230240250260270280290300310320330340350360370380390400410420430440450

-300

-275

-250

-225

-200

-175

-150

-125

-100 -7

5

-50

-25 0 25 50 75 100

125

150

175

200

225

250

275

300

Chainage x [m]

Ele

vatio

n y

[mm

]


66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 3 2 1 0 1 2 3 6 7 8 9 10 11 12 13

Segment Node No. 5090 Segment Node No. 5113

1

76

543

2

424140393837363534333231

3029

282726252423

2221

2019

1817

161514

131211

109

S8

S9

S10

S11

S12

S13

S14

S15

S16

S17

S18

S19

S20

S21

S22

S23

S24

S25

S26

S27

S28

S29

S30

S31

S32

S33 S33

S7

Stage Deflections

-80

-30

20

70

120

170

220

270

320

370

420

-300 -294 -288 -282 -276 -270 -264 -258 -252 -246 -240 -234 -228 -222 -216 -210 -204 -198 -192 -186 -180 -174 -168 -162 -156 -150 -144 -138 -132 -126 -120 -114 -108 -102 -96 -90 -84 -78 -72 -66 -60 -54 -48 -42 -36 -30 -24 -18 -12 -6 0 6 12 18 24 30 36 42

Deformation at previous stage Deformation after completion of this stage : LC1190 Deformation at handover for traff ic movement (Design Camber) @ T=0 : LC1298

Lift Non-stay Segment


66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 3 2 1 0 1 2 3 6 7 8 9 10 11 12 13


1

76

543

2

424140393837363534333231

3029

282726252423

2221

2019

1817

161514

131211

109

S7

S8

S9

S10

S11

S12

S13

S14

S15

S16

S17

S18

S19

S20

S21

S22

S23

S24

S25

S26

S27

S28

S29

S30

S31

S32

S33 S33

Stage Deflections

-80

-30

20

70

120

170

220

270

320

370

420

-300 -294 -288 -282 -276 -270 -264 -258 -252 -246 -240 -234 -228 -222 -216 -210 -204 -198 -192 -186 -180 -174 -168 -162 -156 -150 -144 -138 -132 -126 -120 -114 -108 -102 -96 -90 -84 -78 -72 -66 -60 -54 -48 -42 -36 -30 -24 -18 -12 -6 0 6 12 18 24 30 36 42


Stress Previous Cable to Ft


67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 3 2 1 0 1 2 3 6 7 8 9 10 11 12 13


1

76

543

2

424140393837363534333231

3029

282726252423

2221

2019

1817

161514

131211

109

S7

S8

S9

S10

S11

S12

S13

S14

S15

S16

S17

S18

S19

S20

S21

S22

S23

S24

S25

S26

S27

S28

S29

S30

S31

S32

S33 S33

Stage Deflections Lift Stay Segment

-80

-30

20

70

120

170

220

270

320

370

420

-300 -294 -288 -282 -276 -270 -264 -258 -252 -246 -240 -234 -228 -222 -216 -210 -204 -198 -192 -186 -180 -174 -168 -162 -156 -150 -144 -138 -132 -126 -120 -114 -108 -102 -96 -90 -84 -78 -72 -66 -60 -54 -48 -42 -36 -30 -24 -18 -12 -6 0 6 12 18 24 30 36 42



Stage Deflections Install Cable and stress to Fi

67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 3 2 1 0 1 2 3 6 7 8 9 10 11 12 13


1

76

543

2

424140393837363534333231

3029

282726252423

2221

2019

1817

161514

131211

109

S6

S7

S8

S9

S10

S11

S12

S13

S14

S15

S16

S17

S18

S19

S20

S21

S22

S23

S24

S25

S26

S27

S28

S29

S30

S31

S32

S33 S33

-80

-30

20

70

120

170

220

270

320

370

420

-300 -294 -288 -282 -276 -270 -264 -258 -252 -246 -240 -234 -228 -222 -216 -210 -204 -198 -192 -186 -180 -174 -168 -162 -156 -150 -144 -138 -132 -126 -120 -114 -108 -102 -96 -90 -84 -78 -72 -66 -60 -54 -48 -42 -36 -30 -24 -18 -12 -6 0 6 12 18 24 30 36 42



Erection Monitoring

P19 tower Pilecap

Tower Leg Construction in Progress

Isometric View of Piertable

Piertable Truss Erection

Pier table Truss Erection

Lifting Frame Operations

Lifting Frame Operations

Segment Transportation on Barge

Piertable Segment Lifting with Lifting Frame

Pier Table Segment Alignment

Segment Supported on Pier Table Truss

Pier Table Segments Alignment in Progress

Diaphragm Concreting

Isometric view of Middle Tower Legs

Construction of Middle Tower with ACS










P19 Middle tower leg in Progress



Strutting at Junction Top

Strutting at Junction Top

Assembly of tower head formwork prototype

Alignment of Anchorage Boxes at 100m above MSL

Construction of Tower Head

Erection of Deck

Erection of Deck

Erection of Parallel Wire Stay Cables



Erection of Precast Segmental Deck


Erection of Precast Segmental Deck – Deck Closure




Completed View of Bandra CSB


Conclusions

• Indian Engineers are Well Experienced in Construction of loang Span Bridges, and Erection of Bridge Decks, using various methods

• Choice of the method is Site Specific and Design Specific • Bridge Design should Suit Erection Method

I acknowledge with Thanks opportunity given to me for presentation of a very important and interesting topic. I thank the organizers, and the audience.

Disclaimer

This presentation contains certain forward looking statements concerning future business prospects and profitability of HCC, which are subject to a

number of risks and uncertainties and actual results could materially differ from those in such forward looking statements, important developments

that could affect the company's operations include a downtrend in the infrastructure sector, significant changes in political and economic

environment in India, tax laws, labor relations, litigation etc. The company does not undertake to make any announcement in case any of these

forward looking statements become materially incorrect in future or update any forward looking statements made from time to time by or on behalf

of the company.

Documents

Suhas P Khedkar