Arch bridge
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FremontBridgePortlandOregon.jpg
An arch bridge is a bridge with abutments at each end shaped as a curved arch. Arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust against abutments at either side. A bridge made of a series of arches is called a viaduct. Arch bridges were first invented by the Ancient Greeks, who built them out of stone. Later, the Ancient Romans used cement in their arch bridges. Some of these bridges are still standing today.
Arch bridges are constantly under compression, hence the Romans could use stone, a readily available and durable material, to build them. Stone has good compressive strength, but is weak in tension.
The Romans only used semicircular arches, but longer and thinner bridges are possible with elliptical arches.
See also
External links
- NOVA Online - Super Bridge - Arch Bridges (http://www.pbs.org/wgbh/nova/bridge/meetarch.html)
- Matsuo Bridge Co. - Arch Bridges (http://www.matsuo-bridge.co.jp/english/bridges/basics/arch.shtm)