Fun Facts about Bridges for Kids
· Have you ever built a bridge? Stretching a log over a stream is a simple type of bridge. Dropping stones in a creek to pass is also a type of bridge.
· You might have seen beam bridges over small rivers and creeks. A beam bridge is made by building two piers or towers. Boards are placed over the piers to make a bridge. The boards press down on the piers, so these types of bridges aren’t very strong. They are usually pretty short.
· What would happen if you reinforced a beam bridge with metal poles pieced together in a pattern of squares or triangles? You’d have a truss bridge. A truss bridge is stronger than a beam bridge because the trusses help distribute some of the weight. The trusses run horizontally between each beam.
· Arch bridges are very strong. Ancient Romans made arch bridges out of stone. These bridges were made of columns joined by arches.
· Suspension bridges like the San Francisco Bay Bridge use a completely different approach. Tall towers are built. Then long metal cables attached to the towers suspend the road in place. Piers and trusses are usually built underneath for additional support. The Chinese built the first suspension bridges in 300 A.D. They used twisted bamboo fibers instead of steel cables.
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