egce 406 bridge design - mahidolmucc.mahidol.ac.th/~egpcp/handout406/bridge design - types4.pdf ·...
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EGCE 406Bridge Design
Praveen ChompredaMahidol UniversityFirst Semester, 2007
II. Bridge Types
Components of BridgeSubstructure
Foundation (Pile/ Spread Footing)Pier (Column)Abutment
SuperstructureAny structures above bearing which support the roadwayWearing Surface
foundation
deck bearings
abutment
pier
Components of Bridge
Abutment Abutment
Superstructure
Substructure
Roadway Deck
Pier
Abutment
Superstructure
Substructure
Roadway Deck
Components of Bridge
Bearing
Components of Bridge
Bearing
Components of Bridge
Cap Beam
Bearing
Pin Joint
Components of Bridge
Cap Beam
Bearing
Superstructure
Pier
Components of Bridge
Cap Beam
Superstructure
Piers
Span Length
Span > 6 m BridgeSpan < 6 m Culvert
span multi span
span length
single span
Short span: 6-30 mMedium span: 30-100 mLong span: > 100 m
Types of Bridge
Types by Kinds of TrafficTypes by Traffic Position
Types by Material and FabricationTypes by Structural System
Types of Bridge by Traffic
Highway bridge (trucks, cars)Pedestrian bridge (pedestrians, bicycles)Railway bridge (trains)Transit guideway (city trains, monorail)Other types (pipelines, utilities, industrial, aqueduct, airportstructure)
Types: Highway Bridge
Avon Mouth BridgeBristol, UK
Golden Gate BridgeCalifornia, USA
Types: Pedestrian Bridge
El Alamillo BridgeSeville, Spain200m span
Japan Bridge (1994) Paris, France
100m span
Types: Railway Bridge
Stoney Creek Bridge (1894)Canada
325ft span
Mountain Creek Bridge (1880)Canada
Types: Transit Guideway
BTS SystemBangkok, Thailand
Types: Others
Pont du Gard (Roman Aqueduct) (circa 19 BC) Nimes, France
Roman AqueductSpain
Types: Others
Runway at the Los Angeles International Airport (LAX)Los Angeles, USA
Types: Others
Navigational Canal Netherlands
Types of Bridge by Traffic PositionDeck type
Structural components under the deckPreferred by drivers (can clearly see the view)Requires space under the bridge
Through typeStructural components above the deckObstructed view (not a problem for railway bridges)No structure under the bridge
Half-through type
Types: Deck Type
Henry Hudson Bridge (1936)
Rhone BridgeFrance
Types: Through TypeFirth of Forth Bridge (1890)
Scotland521m span
Types: Through Type
Tonegawa River Bridge (1972) Japan
Types: Deck + Through Type Types: Half-Through
Types by Material & FabricationsMaterials
Masonry (brick, rock)TimberReinforced Concrete (RC)Prestressed Concrete (PC)IronSteelAluminumCompositesPlasticsEtc…
FabricationsPrecast (RC/PC)Cast-in-place (RC/PC)Pretensioned (PC)Posttensioned (PC)Prefabricated (steel)Rivet (steel)Bolted (steel/ timber)Welded (steel)Etc…
Types by Material & Fabrications
Timber Bridgeprobably built in place?
Types by Material & Fabrications
Leonardo Da Vinci Bridge (2001)Norway40 m SpanGlue-laminated Timber Bridge
Types by Material & Fabrications
Steel Prefabricated(probably with precast slab)
Types by Material & Fabrications
Prestressed & Precast & Pretensioned(with perhaps precast slab)
Types by Material & FabricationsPrestressed Segmental BridgePrecast & Post-Tensioned
Types of Bridge by Structure
ArchBeamCantileverCable-StayedSuspensionOthers
Types: Arch Bridge
Types: Arch BridgeSemi-circle (has vertical reaction force only)Flat arch (has vertical and horizontal forces at the support)Tied arch (tie resists tension force)
Types: Arch Bridge
keystone
hingless
2 hinged
3 hinged
voussoir
tie
Hinge changes the degree of indeterminatcy in the structure
Types: Arch Bridge
Hinge Detail at the top of an arch bridge
Types: Arch Bridge
The arch construction was invented during the Roman empire
Ponte dei Salti Bridge (circa 1st century AD)
SwitzerlandMasonry Arch
MaterialsMasonryTimberConcrete (Reinforced/ Prestressed)Steel
Types: Masonry Arch BridgePonte Fabricio and Ponte Cestio (65 BC) Tiberina Island, Italy
Types: Masonry Arch Bridge
Ponte Fabricio (65 BC) Tiberina Island, Italy
Ponte Cestio (65 BC) Tiberina Island, Italy
Types: Masonry Arch Bridge Types: Masonry Arch Bridge
Types: Masonry Arch Bridge Types: Concrete Arch Bridge
Bixby Bridge (1932)California, USA
97.5 m spanConcrete arch
Types: Concrete Arch Bridge
Enz Bridge (1961)Mülacker, Germany
46 m spanConcrete arch
Types: Prestressed Concrete Arch
Natchez Trace Parkway Bridge (1994)Tennessee, USA502 m span
Types: Steel Arch Bridge
Sydney Harbor Bridge (1938)Sydney, Australiaparabolic arch 503 m span
Types: Steel Arch Bridge
Construction of Sydney Harbor Bridge
Types: Beam/Girder Bridges
The most basic type of bridgeConsists of a beam simply supported on each side by a pier and can be made continuous laterTypically inexpensive to build
Types: Beam/Girder Bridges
Common MaterialsTimber TrussRC BeamSteel Plate Girder/ Box GirderSteel Truss GirderPrestressed Concrete Precast Girder
I-Beam, U-Beam, T-BeamSegmentally Prestressed Box Beam
Types: Beam/Girder Bridges
simple
cantilever
continuous
Currently, most of the beam bridges are precast (in case of RC and PC) or prefabricatedMost are simply-supportedSome are made continuous on site
Types: Beam/Girder Bridges
Mountain Creek Bridge (1880)CanadaTimber
Types: Beam/Girder Bridges
Steel sections may be hot-rolled shapes (for short-span bridge), Box section (medium span), or Plate Girder (medium span)
hot-rolled box plate girder sections
Types: Beam/Girder BridgesSteel Box Girder Bridge
Types: Beam/Girder Bridges
Upper: Steel Plate Girder BridgeLower: Prestressed Concrete I-Girder Bridge
Types: Beam/Girder Bridges
Steel Plate Girder
Types: Beam/Girder Bridges
Steel Plate Girder(Continuous)
Types: Beam/Girder Bridges
13@2" =26"
6'9"
8"
54"
AASHTO Type IV Girder.
6@2" =12"
28 o 0.5" strands
Typical Cross-Section of Pretensioned AASHTO Type IV girder
Prestressed Concrete Precast (and Pretensioned) sections are usually of I-shape
Types: Beam/Girder BridgesPrecast Pretensioned Prestressed Concrete BridgeSimply-Supported Beam
Types: Beam/Girder BridgesPost-Tensioned Prestressed Concrete are often found in the form of segmentally precast members
Types: Beam/Girder Bridges Types: Beam/Girder BridgesSegmental construction may be constructed in 2 ways
Cantilever Construction –construct from the pier equally on both sidesSpan-by-Span Construction –finish one span at a time
Cantilever
Span-by-Span
Types: Beam/Girder Bridges
Some types of truss bridges can also be considered as a “beam bridge”when looked globally
Types: Beam/Girder Bridges
Types: Beam/Girder Bridges
Steel Truss can be of beam type, arch type, or cantilever typedepending on the primary mechanisms
Types: Beam/Girder Bridges
Components of Truss
Types: Cantilever BridgesBridge roadway is constructed out from the pier in two direction at the same time so that the weight on both side counterbalance each other
Types: Cantilever Bridges
Types: Cantilever Bridges
Steel Truss CantileverPrestressed Concrete Segmental Cantilever Beam
Types: Steel Truss Cantilever Bridge
350'
150'
1700' Firth of Forth Bridge (1890)Scotland
521m span
Types: Steel Truss Cantilever Bridge
Firth of Forth Bridge (1890)Scotland
521m span
Types: Steel Truss Cantilever Bridge
Types: Cantilever BridgesPrestressed Concrete Segmental Cantilever Beam
Columbia River Bridge
USA 1950 ft span
Types: Cable-Stayed Bridge
PIER PIER
ROADWAY DECK
TOWER/ PYLON
Vertical Loads from Traffic
TOWER/ PYLON
Reaction Force Reaction Force
Types: Cable-Stayed Bridge
All the forces are transferred to the pylon
Roadway Materials(Prestressed) Concrete Box RoadwaySteel Box RoadwaySteel Truss Roadway
Types: Cable-Stayed Bridge
Steel Box Beam
I-Shaped Cross Beam
PrecastConcrete Panel
Deck
Types: Cable-Stayed BridgeHarp Type
Fan Type
Types: Cable-Stayed BridgeCable-Stayed Bridge
Rama IX Bridge
Bangkok
450m span
Tatara Bridge
Japan
890m span
Types: Cable-Stayed Bridge Types: Cable-Stayed BridgeConstruction sequence
Types: Cable-Stayed Bridge Types: Cable-Stayed Bridge
Types: Cable-Stayed Bridge Types: Cable-Stayed Bridge
Types: Suspension BridgeSuspension bridge needs to have very strong main cableCables are anchored at the abutment abutment has to be massive
PIER PIER
Vertical Loads from Traffic
ROADWAY DECK
ABUTMENTABUTMENT
TOWER/ PYLONTOWER/ PYLON
Types: Suspension Bridge
Types: Suspension Bridge
London Tower Bridge (1894)London, UK
Types: Suspension Bridge3 Hinges Suspension BridgeTension member is a truss
Types: Suspension Bridge
Tacoma Narrows Bridge (1940)Washington, USA2800 ft span
Types: Suspension BridgeMackinac Bridge (1957)Michigan, USA1158 m span
Types: Suspension Bridge
Akashi Kaikyo Bridge (1998) Japan 1991m central span
Types: Suspension BridgeMillennium Footbridge (2002)London, UK144m span
Types: Suspension Bridge Types: Suspension Bridge
Types: Others
Pontoon (Floating) Bridge
Types: Others
Gateshead Millennium Bridge (2000)Gateshead, UK126m span
The bridge can rotate to allow ships
to go under
Types: Others
Charing Cross Bridge (middle - truss) and Golden Jubilee Bridges (outer – cable-stayed).
Which type should I use?Consider the followings:
Span lengthBridge lengthBeam spacingMaterial availableSite conditions (foundations, height, space constraints)Speed of constructionConstructabilityTechnology/ Equipment availableAestheticsCostAccess for maintenance
Span Length
0 200 400 600 800 1000 1200 1400 1600 1800 2000
slab
concrete girder
steel girder
cable-stayed concrete
cable-stayed steel
steel truss
concrete arch
steel truss arch
steel rib arch
steel suspension
Typ
es
Span Length (m)
Types min maxslab 0 12concrete girder 10 220steel girder 10 270cable-stayed concrete 90 250cable-stayed steel 90 350steel truss 90 550concrete arch 90 300steel truss arch 250 500steel rib arch 120 370steel suspension 300 2000
Span Length
Cost vs. Span Length
The span length may be influenced by the cost of superstructure (cost/meter) and substructure (cost/pier)If the substructure cost is about 25% of total cost shorter span is more cost-effectiveIf the substructure cost is about 50% of total cost longer spans are more economical
Cost vs. Span Length
Substructure here is expensive compared with superstructure
Cost vs. Span Length
If the water is shallow, substructure is inexpensive compared with superstructure
Access for Maintainence
Total Cost = Initial Cost + Maintenance CostBridge should be made easy to inspect and maintainMaintenance cost may govern the selection of bridge
Steel bridge needs a lot of maintenance in coastal regionsConcrete bridge usually require the least maintenance
Beam SpacingBeam spacing determine the number of girdersLarge Spacing
Fewer girder (faster to erect)Deeper and heavier girder (can it be transported?)Reduced redundancyThicker slab
Smaller SpacingMore girderSmaller girderMore redundancy (but more beams to inspect)Thinner slab
Materials
SteelConcrete
Cast-in-placePrecast
Material choice depends on the cost of material at the bridge siteShipping cost from fabricators
Speed of construction
In urban areas, the construction of bridge may disrupt trafficPrefabricated/ Precast member are the only choiceSubstructure construction may disrupt traffic more than the superstructure erection may consider longer spans
Site Requirement
Is the bridge straight or curvedPrecast I-Girder cannot be curvedSegmental prestressed can have slight curveCast-in-place
Is shipping channel required?Shipping of prefabricated pieces to siteIs the temporary falsework required? Can it be done with the site conditions?
Site Requirement
Requirement for shipping channel leads to long span bridge
Site Requirement
Segmental pieces may be easier to ship in narrow urban streets
Site Requirement
In the Millau Aqueduct, the superstructure was completed inland and pushed into the span
Site Requirement
Aesthetics
An ugly bridge, however safe, serviceable, and inexpensive, is not a good bridgeLong span bridge over a river can be a landmark; thus, aesthetics should be an important factorBridge should blend with the environmentSmooth transition between membersAvoid unnecessary decorationsBridge should have an appearance of adequate strength
Aesthetics
Determinant of bridge’s appearance (in order of importance)Vertical and Horizontal geometry relative to surrounding topography and other structuresSuperstructure type: arch, girder, etc…Pier placementAbutment placementSuperstructure shape, parapet and railingPier shapeAbutment shapeColor, surface texture, ornamentationsSigning, Lighting, Lanscaping
Aesthetics Aesthetics
Aesthetics Aesthetics
Aesthetics