Bridge Types

EGCE 406EGCE 406Bridge Design

II. Bridge Typesg yp

Praveen Chompreda

Mahidol UniversityFirst Semester, 2007

Components of BridgeComponents of Bridge

SubstructureF d (P l / S d F )

SuperstructureA b b Foundation (Pile/ Spread Footing)

Pier (Column) Abutment

Any structures above bearing which support the roadway

Wearing Surface Abutment g

deck bearings

pierpier

abutment

foundation


Superstructure

Substructure

Roadway Deck

Abutment Abutment

Substructure

SSuperstructureRoadway Deck

Pier

Abutment

Substructure


Bearing

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Pin Joint

C B

Bearing

Cap Beam


SuperstructureSuperstructure

Cap Beam

Bearing

Cap Beam

Pier

Span LengthSpan Lengthspan length

single span

span lti multi span

Span > 6 m Bridge Span < 6 m Culvert Short span: 6-30 m Medium span: 30-100 m Span 6 m Culvert Long span: > 100 m

T f B idTypes of Bridge

Types by Kinds of Traffic

Types by Traffic Position

Types by Material and FabricationTypes by Material and Fabrication

Types by Structural System

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Types of Bridge by TrafficTypes of Bridge by Traffic

Highway bridge (trucks, cars) Pedestrian bridge (pedestrians, bicycles) Railway bridge (trains)y g ( ) Transit guideway (city trains, monorail) Other types (pipelines utilities industrial aqueduct airport Other types (pipelines, utilities, industrial, aqueduct, airport

structure)

Types: Highway BridgeTypes: Highway Bridge

Golden Gate BridgeCalifornia, USA

Avon Mouth BridgeBristol, UK

Types: Pedestrian BridgeTypes: Pedestrian Bridge

El Alam illo BridgeSeville, Spain200m span

Japan Bridge (1994) Japan Bridge (1994) Paris, France

100m span

Types: Railway BridgeTypes: Railway Bridge

Mountain Creek Bridge (1880)

Stoney Creek Bridge (1894)

Mountain Creek Bridge (1880)Canada

Stoney Creek Bridge (1894)Canada

325ft span

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Types: Transit GuidewayTypes: Transit Guideway

BTS SystemBangkok, Thailand

Types: OthersTypes: Others

R A d tRoman AqueductSpain

Pont du Gard (Roman Aqueduct) (circa 19 BC) N FNimes, France


Runway at the Los Angeles International Airport (LAX)Los Angeles, USAg


Navigational Canal Netherlands

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Types of Bridge by Traffic Positionyp g y

Deck type Structural components under the deck Preferred by drivers (can clearly see the view) Requires space under the bridge

Through type Structural components above the deck Obstructed view (not a problem for railway bridges) No structure under the bridge

Half-through type

Types: Deck TypeTypes: Deck Type

Rhone BridgeFrance

Henry Hudson Bridge (1936)

France

Types: Through TypeTypes: Through Type

Firth of Forth Bridge (1890)ScotlandScotland

521m span

Types: Through TypeTypes: Through Type

Tonegawa River Bridge (1972) JJapan

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Types: Half-ThroughTypes: Half Through Types by Material & FabricationsTypes by Material & Fabrications

MaterialsM (b k k)

FabricationsP (RC/PC) Masonry (brick, rock)

Timber Reinforced Concrete (RC)

Precast (RC/PC) Cast-in-place (RC/PC) Pretensioned (PC) Reinforced Concrete (RC)

Prestressed Concrete (PC) Iron

Pretensioned (PC) Posttensioned (PC) Prefabricated (steel)

Steel Aluminum

( )

Rivet (steel) Bolted (steel/ timber)

Composites Plastics Etc

Welded (steel) Etc

Etc

Types by Material & FabricationsTypes by Material & Fabrications

Timber Bridgeprobably built in place?


L d D V B d (2001)Leonardo Da Vinci Bridge (2001)Norway40 m SpanGlue-laminated Timber Bridge

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Steel P f b i dPrefabricated(probably with precast slab)


Prestressed & Precast & PretensionedPrestressed & Precast & Pretensioned(most likely with precast concrete slab)


Prestressed Segmental BridgePrecast & Post TensionedPrecast & Post-Tensioned

Types of Bridge by StructureTypes of Bridge by Structure

Arch Beam Cantilever Cable-Stayed Suspension Suspension Others

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Types: Arch BridgeTypes: Arch Bridge

Forces Along the Arch

Reaction ForcesReaction Forces


Semi-circle (has vertical reaction f l )force only)

Flat arch (has vertical and horizontal forces at the support)horizontal forces at the support)

Tied arch (tie resists tension force))


Hinge changes the degree of i d i i h hingless indeterminatcy in the structure

2 hi d2 hinged

3 hinged

keystone

3 hinged

tie

voussoir


Hinge Detail at the top of an arch bridge

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Ponte dei Salti Bridge (circa 1st century AD)

Switzerland

Th h i

SwitzerlandMasonry Arch

M i l The arch construction was invented during the Roman empire

Materials Masonry Timberempire Timber Concrete (Reinforced/ Prestressed) Steel

Types: Masonry Arch BridgeTypes: Masonry Arch Bridge

Ponte Fabricio and Ponte Cestio (65 BC), Tiberina Island, ItalyPonte Fabricio and Ponte Cestio (65 BC), Tiberina Island, Italy

Types: Masonry Arch BridgeTypes: Masonry Arch Bridge Types: Masonry Arch BridgeTypes: Masonry Arch Bridge

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Types: Masonry Arch BridgeTypes: Masonry Arch Bridge Types: Concrete Arch BridgeTypes: Concrete Arch Bridge

Bixby Bridge (1932)California, USA

97.5 m span97.5 m spanConcrete arch

Types: Concrete Arch BridgeTypes: Concrete Arch Bridge

Enz Bridge (1961)Mlacker, Germany

46 m spanConcrete arch

Types: Prestressed Concrete ArchTypes: Prestressed Concrete Arch

Natchez Trace Parkway Bridge (1994)Tennessee, USA502 m span

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Types: Steel Arch BridgeTypes: Steel Arch Bridge

Sydney Harbor Bridge (1938)Sydney, Australiaparabolic arch 503 m span

Types: Steel Arch BridgeTypes: Steel Arch Bridge

Construction of Sydney Harbor Bridgey y g

Types: Beam/Girder BridgesTypes: Beam/Girder Bridges

Vertical Loads from Traffic

ROADWAY DECK

BEAM

The most basic type of bridge

BEAM Typically consists of a beam simply supported on each side by a pier

PIER PIERon each side by a pier and can be made continuous later

Typically inexpensive to build


Common Materials

Timber Truss RC Beam Steel Plate Girder/ Box Girder Steel Truss Girder Prestressed Concrete Girders

I-Beam, U-Beam, T-Beam Segmentally Prestressed Box Beam Segmentally Prestressed Box Beam

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Types: Beam/Girder Bridgesyp g

simple

cantilever

continuous

C l f h b b id (i f RC d PC) Currently, most of the beam bridges are precast (in case of RC and PC) or prefabricated

Most are simply-supported Most are simply-supported Some are made continuous on site


Mountain Creek Bridge (1880)CanadaTimber


hot-rolled box plate girder sections sections

Steel sections may be hot-rolled shapes (for short-span bridge), Box section (medium span), or Plate Girder (medium span)


Steel Box Gi d Girder Bridge

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Upper: Steel Plate Girder BridgeLower: Prestressed Concrete I-Girder Bridge


Steel Plate Girder


Steel Plate Girder(C ti )(Continuous)


6'9" Prestressed Concrete

P t ( d P t i d)

8"

Precast (and Pretensioned) sections are usually of I-shapep

54"

28 o 0.5" strands

13@2" =26"

6@2" =12"

@

T T i d

Typical Cross-Section of Pretensioned AASHTO

AASHTO Type IV Girder. Type IV girder

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Precast Pretensioned Prestressed Concrete BridgeSi l S d BSimply-Supported Beam


Post-Tensioned Prestressed Concrete are often found in the form of t ll t bsegmentally precast members

Types: Beam/Girder BridgesTypes: Beam/Girder Bridges Types: Beam/Girder BridgesTypes: Beam/Girder Bridges

Segmental construction may be t t d i 2 constructed in 2 ways

Cantilever Construction construct from the pier equally p q yon both sides

Span-by-Span Construction finish one span at a timefinish one span at a time

Span-by-Span

Cantilever

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Some types of truss bridges can also be considered as a beam bridge h l k d l b llwhen looked globally



Steel Truss can be of beam type, arch type, or cantilever typedepending on the primary mechanismsdepending on the primary mechanisms


Components of Truss

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Types: Cantilever BridgesTypes: Cantilever Bridges

In a cantilever bridge, the roadway is constructed out from the pier in two di ti t th ti th t th i ht b th id t b l directions at the same time so that the weight on both sides counterbalance each other

Notice the larger section at the support to resist negative moments Notice the larger section at the support to resist negative moments



Steel Truss Cantilever Prestressed Concrete Segmental Cantilever Beam

350'

150'

1700'

Firth of Forth Bridge (1890), Scotland521m span

Types: Steel Truss Cantilever BridgeTypes: Steel Truss Cantilever Bridge

Firth of Forth Bridge (1890)Scotland

521m span

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Types: Steel Truss Cantilever Bridgeyp g Types: Cantilever BridgesTypes: Cantilever Bridges

Prestressed Concrete Segmental Cantilever BeamColumbia River Bridge

USA 1950 ft span

Types: Cable-Stayed BridgeTypes: Cable Stayed BridgeTOWER/ PYLON TOWER/ PYLON


ROADWAY DECK

PIER PIERPIER PIER

Reaction Force Reaction Force

Types: Cable-Stayed BridgeTypes: Cable Stayed Bridge

Cable-stayed bridge uses the prestressing principles but the prestressing tendons are external of the beamtendons are external of the beam All the forces are transferred from the deck through the cables to the pylon

Roadway deck can be: (Prestressed) Concrete Box Deck Steel Box Deck Steel Truss Deck Steel Truss Deck

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P t Steel Box

Beam

I-Shaped Cross Beam

Precast Concrete Panel

Roadway


Harp Type

Fan Type Fan Type


Cable-Stayed BridgeRama IX Bridge

Bangkok

450m spanp

Tatara Bridge

JapanJapan

890m span


Millau ViaductFranceFrance

I d i l Ri R d B idIndustrial Ring Road BridgesBangkok, Thailand

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Types: Cable-Stayed BridgeTypes: Cable Stayed Bridge Types: Cable-Stayed BridgeTypes: Cable Stayed Bridge

Construction sequence

Construct Pylons


Erect the deck away from the pylon in both of the pylons.


Join the cable-stayed sections with the back piers (back piers helps resist tension forces)

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The concrete roadway deck is laid as the deck structure is erected


Finally, join the two cantilevers at the midspan

Types: Suspension BridgeTypes: Suspension Bridge

Suspension bridge needs to have very strong main cables Cables are anchored at the abutment abutment has to be massive

TOWER/ PYLONTOWER/ PYLON


ROADWAY DECK

PIER PIER

ABUTMENTABUTMENT

Types: Suspension Bridgeyp p g

Forces in Main Cable

Reaction Forces

Reaction Force Reaction Force

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Anchor of a suspension bridge


London Tower Bridge (1894)London, UK

3-Hinged Suspension Bridge Tension member is a truss Tension member is a truss


Mackinac Bridge (1957)Mi hi USAMichigan, USA

1158 m span

Tacoma Narrows Bridge (1940)Washington, USA2800 f 2800 ft span


Akashi Kaikyo Bridge (1998) Akashi Kaikyo Bridge (1998) Japan 1991m central span

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Millennium F b id Footbridge (2002)London, UK144m span


Types: Suspension BridgeTypes: Suspension Bridge Types: Othersyp

Pontoon (Floating) Bridge

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The bridge can The bridge can rotate to allow ships

to go under

Gateshead Millennium Bridge (2000)Gateshead Millennium Bridge (2000)Gateshead, UK126m span


Charing Cross Bridge (middle - truss) and Golden Jubilee g g ( ) JBridges (outer cable-stayed).

Which type should I use?Which type should I use?

Consider the followings:

Span length Bridge length

B i Beam spacing Material available Sit diti (f d ti h i ht t i t ) Site conditions (foundations, height, space constraints) Speed of construction Constructability Constructability Technology/ Equipment available Aesthetics Aesthetics Cost Access for maintenance Access for maintenance

Span LengthSpan Length

st eel suspension

st eel rib arch

st eel suspension

concret e arch

st eel t russ arch

scable- st ayed st eel

st eel t russ

Type

s

Types m in m axslab 0 12concrete girder 10 220t l i d 10 270

st eel girder

cable- st ayed concret esteel girder 10 270cable-stayed concrete 90 250cable-stayed steel 90 350steel t russ 90 550

l b

concret e girder

st eel girderconcrete arch 90 300steel t russ arch 250 500steel r ib arch 120 370steel suspension 300 2000

0 200 400 600 800 1000 1200 1400 1600 1800 2000

slab

Span Length ( m )Span Length ( m )

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Span LengthSpan Length Cost vs. Span LengthCost vs. Span Length

The span length may be influenced by the cost of superstructure ( t/ t ) d b t t ( t/ i )(cost/meter) and substructure (cost/pier)

If the substructure cost is about 25% of total cost shorter span is more cost-effectivecost effective

If the substructure cost is about 50% of total cost longer spans are more economical

Cost vs. Span LengthCost vs. Span Length

Substructure here is expensive compared with the superstructuresuperstructure

If the water is shallow, substructure is inexpensive p

compared with the superstructure

Access for MaintenanceAccess for Maintenance

Total Cost = Initial Cost + Maintenance Cost Bridge should be made easy to inspect and maintain Maintenance cost may govern the selection of bridgey g g

Steel bridge needs a lot of maintenance in coastal regions Concrete bridge usually require the least maintenanceg y q

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Beam SpacingBeam Spacing

Beam spacing determine the number of girdersnumber of girders Large Spacing Fewer girder (faster to erect) Deeper and heavier girder (can it

be transported?) Reduced redundancy Reduced redundancy Thicker slab Smaller Spacing More girder Smaller girder More redundancy (but more More redundancy (but more beams to inspect) Thinner slab

MaterialsMaterials

Steel Concrete

Cast-in-place Precast

Material choice depends on the cost of material at the bridge p gsite

Shipping cost from fabricatorsS pp g cost o ab cato s

Speed of constructionSpeed of construction

In urban areas, the construction of bridge may disrupt traffic Prefabricated/ Precast member are the only choice Substructure construction may disrupt traffic more than the

i id l superstructure erection may consider longer spans

Site RequirementSite Requirement

Is the bridge straight or curved

Precast I-Girder cannot be dcurved

Segmental prestressed can have slight curveslight curve

Cast-in-place Shipping of prefabricated Shipping of prefabricated

pieces to site

Is shi in channel re ired?Segmental pieces may

be easier to ship in Is shipping channel required? Is the temporary falsework

i d? C i b d i h

narrow urban streets

required? Can it be done with the site conditions?

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Requirement for shipping channel leads to long span bridge


In the Millau Aqueduct, the superstructure was completed inland and pushed into the span

Site RequirementSite Requirement AestheticsAesthetics

An ugly bridge, however safe, serviceable, and inexpensive, is not a good bridge

Long span bridge over a river can be a landmark; thus, aesthetics should be an important factor

Bridge should blend with the environmentg Smooth transition between members Avoid unnecessary decorations Avoid unnecessary decorations Bridge should have an appearance of adequate strength

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AestheticsAesthetics

Determinant of bridges appearance (in order of importance) Vertical and Horizontal geometry relative to surrounding topography

and other structures

S h i d Superstructure type: arch, girder, etc Pier placement

Ab t t l t Abutment placement Superstructure shape, parapet and railing Pier shape Pier shape Abutment shape Color surface texture ornamentations Color, surface texture, ornamentations Signing, Lighting, Lanscaping

AestheticsAesthetics

AestheticsAesthetics AestheticsAesthetics

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