Cantilever Bridges
A cantilever bridge has three sections. The middle section is held, suspended, by the outside two. The two (or more) towers are compressed, because they hold up the two outside sections. The top of the bridge is in tension, because it is pulling on the deck, much like a cable-stayed bridge. The bottom of the bridge is in compression, because it is pushing up on the deck. Cantilever bridges are long bridges. During construction, towers and anchorage are built first. Then, little bits are added, until the two outside sections are built. When adding these little bits, less falsework is needed, because each bit is supported by the last. Once the outer structure is built, the middle section is lifted into place.
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