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Bridge Basics
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Image of New River Gorge Bridge
Arch bridge
being constructed with cables
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How are arch bridges built?
Building an arch bridge isn't easy, since the structure is completely unstable until the two spans meet in the middle. For years, engineers used a technique called centering, in which a wooden form supported both spans until they locked together at the top. A newer method supports the spans using cables anchored to the ground on either side of the bridge. This is how the New River Gorge Bridge in West Virginia was built.


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