Bridges

Types of Bridges

Wajahat GillaniWajahat GillaniShoaib MehmoodShoaib Mehmood

Naeem AwanNaeem AwanSheikh TaimoorSheikh Taimoor

Some Uses of BridgesSome Uses of Bridges

WalkwaysWalkways Highways/RoadsHighways/Roads RailwaysRailways PipelinesPipelines Connecting landsConnecting lands Crossing rivers and Crossing rivers and

streamsstreams

Types of BridgesTypes of Bridges ArchArch

TrussTruss

CantileverCantilever

Cable-StayedCable-Stayed

SuspensionSuspension

What makes a bridge stay What makes a bridge stay up?up?

ForcesForces CompressionCompression – a – a

pushing or pushing or squeezing forcesqueezing force

TensionTension – a pulling – a pulling or stretching forceor stretching force

Arch bridgesArch bridges

The arch is squeezed together, and The arch is squeezed together, and this squeezing force is carried this squeezing force is carried outward along the curve to the outward along the curve to the supports at each end. The supports, supports at each end. The supports, called abutments, push back on the called abutments, push back on the arch and prevent the ends of the arch and prevent the ends of the arch from spreading apart.arch from spreading apart.

Arch BridgesArch Bridges

KeystoneKeystone – the – the wedge-shaped stone wedge-shaped stone of an arch that locks of an arch that locks its parts togetherits parts together

AbutmentsAbutments – the – the structures that structures that support the ends of support the ends of the bridgethe bridge

Arch BridgesArch Bridges

Works byWorks by

CompressionCompression

Arch BridgesArch Bridges

Where have you seen these bridges?Where have you seen these bridges?

Cold Spring Arch Bridge, Santa Barbara, CA

Marsh Rainbow Arch, Riverton, KS

Pont du Gard, Nimes, France

Cable stayed BridgesCable stayed Bridges

The cable-stayed bridge, like the The cable-stayed bridge, like the suspension bridge, supports the suspension bridge, supports the roadway with massive steel cables, roadway with massive steel cables, but in a different way. The cables run but in a different way. The cables run directly from the roadway up to a directly from the roadway up to a tower, forming a unique "A" shape. tower, forming a unique "A" shape.

Cable-Stayed BridgesCable-Stayed Bridges PiersPiers – the vertical supporting structures – the vertical supporting structures CablesCables – thick steel ropes from which the – thick steel ropes from which the

decking is suspendeddecking is suspended DeckingDecking – the supported roadway on a bridge – the supported roadway on a bridge

Cable-Stayed BridgesCable-Stayed Bridges

Works by Works by TensionTension AND AND CompressionCompression

Cable-Stayed BridgesCable-Stayed Bridges

Where have you seen these bridges?Where have you seen these bridges?

Zakim Bridge, Boston, MA

Sunshine Skyway Bridge, Tampa, FL

Naluchi Bridge, Muzaffarabad, Azad Kashmir

Suspension BridgesSuspension BridgesIn all suspension bridges, the In all suspension bridges, the roadway hangs from massive steel roadway hangs from massive steel cables, which are draped over two cables, which are draped over two towers and secured into solid towers and secured into solid concrete blocks, called anchorages, concrete blocks, called anchorages, on both ends of the bridge.on both ends of the bridge.The two towers support most of the The two towers support most of the bridge's weight. bridge's weight.

Suspension BridgesSuspension Bridges

Similar to Cable-StayedSimilar to Cable-Stayed Different construction methodDifferent construction method

Suspension BridgesSuspension Bridges

Works by Works by TensionTension and and CompressionCompression

Suspension BridgesSuspension Bridges

Where have you seen these bridges?Where have you seen these bridges?

Golden Gate Bridge, San Francisco, CA

Brooklyn Bridge, Brooklyn, NY

Verrazano-Narrows Bridge, New York, NY

Truss BridgeTruss Bridge

Every bar in this cantilever bridge Every bar in this cantilever bridge experiences either a pushing or experiences either a pushing or pulling force. The bars rarely bend. pulling force. The bars rarely bend. This is why cantilever bridges can This is why cantilever bridges can span farther than beam bridgesspan farther than beam bridges

Other TypesOther Types

Truss

Southern Pacific Railroad Bridge, Tempe, AZ

Cantilever

Firth of Forth-Forth Rail Bridge, Edinburgh, Scotland