Beam Bridge

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Beam Bridge
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Sidney Lanier Bridge Under Construction
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Beam Bridge Forces When something pushes down
on the beam, the beam bends. Its top edge is
pushed together, and its bottom edge is pulled
apart.
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The continuous span... gives beam bridges the
ability to span great distances. A single beam
bridge rarely spans more than 250 feet. But in
the Chesapeake Bay Bridge-Tunnel, several beam
bridges can be linked together, creating what is
called a continuous span.
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The truss bridge...
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Forces that act on a truss bridge
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The arch bridge..
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Forces that act on an arch bridge
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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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The suspension bridge...
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Forces that act on a suspension bridge...
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Cable-stayed bridges, like the Sunshine Skyway in
Florida, require less cable and can be built much
faster than suspension bridges. Cable-stayed
bridges are becoming the most popular bridges for
medium-length spans (between 500 and 3,000 feet).
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This is what happens when you dont pay attention
in your middle school science class and you get
hired to build a bridge.