02 Technical Lecture ED BRIDGE

2016 201 6 MIDAS Techn Technical ical Chat Ch at

Practical Design of Extradosed Extr adosed Bridg Bridges es

midas Civil

Inki Choi Head-Design(Bridges), Larsen & Toubro Toubro Construction

L&T Construct Construction ion

1. Introduction 2. Design Pro roc cedure 3. Design Example 4. Comparative study 5. Re Reffere ren nce Pro rojject

midas Civil

1. Intr Introduction oduction

Technical Lecture by L&T

Extradosed Extr adosed Bridge? 

Meaning of Extradosed The name comes from the French word extradossé, which is derived from the word extrados extrados,, the exterior curve of an arch. arch . •



Historical Extradosed Bridge Ganter Bridge (Swizerland,1980)

Odawara Blue Way Bridge (Japan,1994)

Kisogawa Bridge (Japan,2001)

1. Introduction Characteristics of Extradoesd bridge 

Aesthetic point of view Looks similar with cable stayed bridge with tower and cable •



Structural behavior point Behave similar with girder bridge •

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Key Aspects Slenderer depth than girder bridge => Less concrete consumption Lower tower height than cable stayed bridge => Easy Construction Economical application to 100m to 200m main span •

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•


1. Introduction


Structural behavior of Extradosed bridges 

Structural difference with Cable-stayed bridges Less Stress variation on cable due to live load. Range of stress variation is important governing factor of stay cables due to fatigue •

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1. Introduction



Distribution Ratio of Vertical Load (β) Distribution on stay cables and girder of vertical uniform load on the main span •

1. Introduction Structural behavior of Extradosed bridges 

Distribution Ratio of Vertical Load (β) Load distribution to girder : 79% Load distribution to stay cable : 21% •

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1. Introduction



Distribution Ratio of Vertical Load (β) vs stress range due to live load

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1. Introduction


Parametric comparison 

Economical parameter for different type TYPE OF BRDIGE

GIRDER DEPTH to SPAN

PYLON HEIGHT to SPAN

APPLICABLE SPAN RANGE

MID

Support

GIRDER BRIDGE (>100m span)

1:40~1:50

1:15~1:20

-

100~180m

EXTRADOSED BRIDGE

1:40~1:50

1:30~1:40

1:8 ~ 1:15

100~200m

1:4 ~ 1:5

200~800m


APPLICABLE SPAN RANGE

CABLE STAYED BRDIGE



1.5m~2.5m uniform

Tentative dimension for 200m main span TYPE OF BRDIGE

GIRDER DEPTH to SPAN MID

Support

GIRDER BRIDGE (>100m span)

5.0m~4.0m 13.5m~10m

-

200m

EXTRADOSED BRIDGE

5.0m~4.0m 7.0m~5.0m

25m ~ 13m

200m

CABLE STAYED BRDIGE

1.5m~2.5m

50m ~ 40m

200m

1. Introduction Parametric comparison 

Equivalent thickness of concrete


1. Introduction Parametric comparison 

Post-tensioning Tendon



1. Introduction

2. Design Procedure 3. Design Example 4. Comparative Study 5. Reference Project

midas Civil

2. Design Procedure


Design procedure flow chart 

Planning / Preparation of Concept / Design basis Understanding Requirement

• •

•

Span arrangement

• •

Decide Cross section

Arranging Stay cable

Determine the loading

• •

• •

• • •

Clearance functional width / traffic lane

Survey information ( Soil / Topo & Bathymetry ) Structural efficiency / Foundation cost Decisi on on bearing system Single cell, multi cell, Steel or Concrete Number of stay cable plane

Fan type Harp type

Dead Load / Superimposed Dead Load Live Load / Wind Load / Thermal effect Seismic loading

2. Design Procedure



Transverse design stage Transverse Analysis

Serviceability limit

• •

• • •

•

Strength limit

Review of clashes Details

Finalizing section

•

• •

Strip model analysis Plate element analysis

Reinforcement design Crack assessment Stress limit of concrete and reinforcement

Bending moment capacity Shear Capacity

Any clash : Transverse tendon duct / rebar / anchorage / duct space Embedded items (drainage scup / lighting foundation / lif ting or handling hole etc.)

2. Design Procedure



Longitudinal analysis stage Longitudinal Analysis

• •

•

Construction stage

• •

Serviceability design

• •

•

Strength limit

• •

•

Additional Cable Check

• •

•

Finalizing Design

• •

Construction Stage Analysis Final s tage Analysis Girder design Stay Cable Design Requirement of temporary PT

Stress limit Stay Cable Check

Bending capacity Shear capacity Torsional capacity Loss of Cable Replacement of Cable Vibration Anchorage details Review of clashes Preparation of casting curve / camber drawing

2. Design Procedure Span Arrangement 

Horizontal and Vertical Clearance Horizontal Clearance shall be decided based on requirement (e.g. Navigational Channel, geometrical requirement) Vertical clearance (Navigational or traffic) •

•



Side span / Main Span ratio 0.6 would be economical parameter in general •


2. Design Procedure


Cross Section / Number of Cable plane 

Single-Cell vs. Multi-cell Depends on the functional requirement(i.e. required width based on traffic assessment) •



Single plane or double plane stay cable Girder Cross section related to cable anchorage •

2. Design Procedure


Stay Cable Design 

Harp type vs. Fan type Cable arrangement shall be decided considering Aesthetics, construction efficiency, overall cost etc. •

Harp Type

Fan Type

Eccentricity

Less Eccentricity

More Eccentricity

Anchor Detail

Simple

Complicated

Shape



Design specification applicable PTI Recommendation for Stay Cable Design, SETRA, EURO CODE •

- SLS PTI

: f limit=0.6fpu (∆f L : not exceed 70MPa in rare comb. )

SETRA : f limit=0.6fpu (∆f L : not exceed 50MPa in frequent comb. ) - ULS

: f limit=0.75fpu (PTI and SETRA)

2. Design Procedure


Stay Cable Design 

PTI Recommendation (6th Edition) Resistance factor given referring AASHTO LRFD design specification load combination •

2. Design Procedure Stay Cable Design 

Euro Code (EN-1993-1-11) •

Ultimate Limit States

•

Serviceability limit States


2. Design Procedure


Girder Design 

During Construction Tensile stress limit : : No tension in Segmental construction, k1f ctm or k6f ctm for cast-in-situ construction (IRC112-2011) Compression stress limit : k1f ck or k6f ck (IRC112-2011) •

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

Service limit State Tensile stress limit : No tension for Segmental construction, f ctm for cast-insitu construction (IRC ) Compression stress limit : 0.48fck •

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2. Design Procedure


Girder Design 

Ultimate limit State Ultimate Moment capacity •

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Ultimate Torsional Capacity

•

Ultimate Shear Capacity

2. Design Procedure Pylon Design 

Aesthetic design


2. Design Procedure


Pylon Design  •

Anchorage Design

Single Tube Type

•

Mono Tube Type

•

Anchor Box Type

2. Design Procedure Pylon Design 

Anchorage Design


2. Design Procedure Procedure Connection to Pylon 

Bearing vs. Monolithic


2. Design Procedure Procedure Expansion Expa nsion Joints Jo ints 

Expansion Joint at Support location Conventional support system No concern about long-term deflection •

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2. Design Procedure Procedure


Expansion Expa nsion Joints Jo ints 

Expansion Joint at Mid Span Needle Beam type type or Hinge Joint •

Needle Beam Type GUIDED BEARING ACTED BY (+) MOMENT MOMENT

GUIDED BEARING ACTED BY (-) MOMENT MOMENT

Hinge Hing e Type



FIXED BEARING ACTED BY (+) MOMENT MOMENT

GUIDED BEARING ACTED BY (+) MOMENT MOMENT

FIXED BEARING ACTED BY (+) MOMENT MOMENT


Otay River Bridge

Port Mann Bridge

2. Design Procedure


Foundation Design Pile foundation vs. Well foundation



Pile Foundation

•

•

Economical in case less scour depth Less construction time and flexible arrangement of pile

Well Foundation

•

applicable if scour depth is high where pile foundation is not feasible

•

Less equipment required

•

High geotechnical lateral resistance

2. Design Procedure Foundation Design 

Construction Methodology of Pile Foundation


2. Design Procedure Foundation Design 

Construction Methodology of Pile Foundation



1. Introduction 2. Design Procedure

3. Design Example 4. Comparative Study 5. Reference Project

midas Civil

3. Design Example Design Parameter 

Material Property Concrete M55 – Superstructure , Upper pylon and lower pylon M35 - Foundation •

•

•

•

Post-tensioning strand E = 195000 MPa Poisson ratio = 0.3 12T15 and 19T15 prestressing tendons Stay cable E = 195000 MPa 15.7mm dia. strand Reinforcement Fe 500 •


3. Design Example Bridge general arrangement 

Span arrangement 110 m + 180 m + 110 m •


3. Design Example Bridge general arrangement 

Cross section Girder Depth : 3.5m ~ 5.5m Deck width : 28.0m •

•


3. Design Example Design Loading Permanent Load Self weight  Super imposed dead Load SIDL variable (Wearing coat , Overlay) SIDL fixed (Crash barrier etc..)  Variable Live Load (IRC112-2011 cl.204) Carriageway live load ( 70R, Class A,..) Pedestrian live load 

•

•

•

•

•


3. Design Example Design Loading 

Thermal Load Temperature gradient (IRC112-2011 cl.215.3) Uniform temperature (IRC112-2011 cl.215.2) •

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•



Stay cable temperature

Wind Load (IRC112-2011 cl.209)


3. Design Example Design Loading 

Seismic Load



Accidental Load Vehicle Collison Barge impact Impact due to floating bodies • • •

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Hydraulic Loads Water current forces Wave pressure Buoyancy • • •

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Construction Loads



Earth pressure


3. Design Example Transverse Analysis 

Transverse Analysis using Beam Model Dead Load, SIDL, Pre-stressing, Thermal load etc. •


3. Design Example


Transverse Analysis 

Transverse Analysis using Beam Model Construction stage analysis considering time- dependent material property •

BMD : Self Weight

BMD : Tendon Primary

3. Design Example Transverse Analysis 

Transverse Analysis using Plate Element Analysis Model Live load dispersion to be taken in to consideration •


3. Design Example Transverse Design Summary 

Typical section Reinforcement drawing


3. Design Example Longitudinal Analysis Model 

Line Beam analysis Model


3. Design Example


Longitudinal Analysis Model 

Loading Application Self-Weight and SIDL Live Load Wind Thermal Seismic •

•

•

• •



Tendon Arrangement Stay Cable Cantilever Tendon

3. Design Example Longitudinal Analysis Model 

Similar scheme with Balanced Cantilever Girder Bridge



Pylon and Stay Cable to be added


3. Design Example Construction Stage Analysis 

Construction stage Analysis Result Construction sequence, age of segment, creep shrinkage •


3. Design Example Construction Stage Analysis 

Casting Curve Reference curve data during fabrication Final total camber + Vertical Profile •

•



Camber Table during erection Reference curve data during erection •

Pylon


3. Design Example Longitudinal Design Summary 

Construction stage result

Top Stresses During Construction Stages




Bottom Stresses During Construction Stages




Girder Stress at bottom & Top - Final Construction Stage



Post Construction stage Analysis result Girder Stress Live Load

Cable Stress Live Load



Service Limit State Result

Top stresses in Rare Combination ( Live load Leading with temperature accompanying)


3. Design Example


Longitudinal Design Summary 

Service Limit State Result

Bottom stresses in Rare Combination ( Live load Leading with te mperature accompanying)


Ultimate Limit State Result (Bending Moment Capacity)



Ultimate Limit State Result (Shear & Torsion Capacity)


3. Design Example Miscellaneous design 

Anchor Blister Design Design as per section no 13 of IRC 112-2011 •



Diaphragm design Design as per section no 13 of IRC 112-2011 •



Bearing and Expansion joint Drainage and street lighting



Pavement





1. Introduction 2. Design Procedure 3. Design Example

4. Comparative Study 5. Reference Project

midas Civil

4. Comparative Study


Description of Case Study 

Bridge Length 400m (=110m + 180m +110m)



Width of deck 28m (6 lane = 2 x 3lane)

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Key Dimension for case studies GIRDER DEPTH to SPAN MID

Support


EXTRADOSED BRIDGE

3.5m

5.5m

22m

GIRDER BRIDGE

3.5m

5.5m

-

Same Depth as Extradosed Bridge

GIRDER BRIDGE

3.5m

10.0m

-

Conventional Balanced Cantilever

TYPE OF BRDIGE

Remark

Extradosed Bridge



Comparison : Balanced Cantilever Bridge vs. Extradosed Bridge 

Extradosed Bridge with external stay cable (Girder depth at support = 5.5m) Elevation

BMD

2,80,000kN.m

Stress No Tension



Comparison : Balanced Cantilever Bridge vs. Extradosed Bridge 

Extradosed Bridge with external stay cable (Girder depth at support = 5.5m) Elevation

BMD

11,25,000kN.m

Stress 19.1 Mpa

Girder depth shall be increased

4. Comparative Study Comparison : Balanced Cantilever Bridge vs. Extradosed Bridge 

Balanced Cantilever Bridge (Girder depth at support = 10.0m) Elevation

BMD

Stress

6,84,100 kN.m

No tension




Findings 





Depth of Girder •

Depth of girder to be increased at support from 5.5m to 10m.

•

Vertical profile to be raised in order to satisfy navigation clearance.

Material Quantity •

Concrete : 15~25% saving in case of extradosed bridge

•

Post-tensioning Tendon : Similar amount tendon consumed

•

Stay cable : additional 150 Ton stay cable required.

Constructability 23m high above deck to be constructed. Additional 1 month construction period •


1. Introduction 2. Design Procedure 3. Design Example 4. Comparative Study

5. Reference Project

midas Civil

5. Reference Projects


Second Vivekananda Bridge (SVBTC), Kolkata 

Feature of project Span configuration Width of bridge Foundation •

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•

: 7 X 110 m + 2 X 55 m (880 m ) : 28.6 m : Well Foundation



3rd Narmada Bridge, Gujarat 


•

•

: 8 X 144 m + 2 X 96 m (1344 m) : 20.8 m : Pile Foundation

5. Reference Projects 3rd Narmada Bridge, Gujarat 

General arrangement drawing




Barapullah Bridge, Delhi 


•

•

: 3 X 127.5 m + 2 X 85 m (552.5 m) : 20.8 m : Well Foundation

5. Reference Projects Barapullah Bridge, Delhi 





Kacchi Dargah, Bihar 

Feature of project Total length Width of bridge Foundation •

•

•

: 9.759 km ( Extradosed Bridge) : 32.4 m : Well Foundation

5. Reference Projects Kacchi Dargah, Bihar 





Mandovi Bridge, Goa : Cable Stayed Bridge 

Feature of project Span Configuration Width of bridge Foundation •

•

•

: 3 X 150 m + 2 X 85 m (620 m) : 21 m : Pile Foundation

5. Reference Projects Mandovi Bridge, Goa : Cable Stayed Bridge 



02 Technical Lecture ED BRIDGE

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