|
|
|
|
|
BRIDGE Reaserch paper
|
|
|
History of bridges No one knows when or who built the first bridge but there are many, now gone, specimens around the world. In Africa and in the jungles rope bridges were made. With rope as its only material, it’s very scary to walk across. Besides the rope bridges simple wood ones were made. Mostly they were just a couple of planks placed across a river or a stream, or even a simple cut tree. The first major advancement in the history of bridges is the use of stone. The Chinese are famous for building the beautiful garden arch bridges. When the thirteen colonies were established there were simple floating bridges consisting of barrels and planks.Then as technology was getting better steel came into use, and soon they used reinforced other materials so not to spend as much money. Now we have advanced system of weight and balance to keep our bridges strong Beam Bridges A beam bridge is a bridge that is made up of a concrete or steel beam that rests on two piers. The main use of this type of bridge is as a crossing for a highway. The beam bridge is also considered the simplest of the modern bridges. A normal concrete beam can support a 50 to 100 feet long span. Reinforced beams are used for longer spans. Cantilever Bridges A cantilever bridge a more complex design of the beam bridge. The difference is that the “beam” of the cantilever bridge is arched (like the title above). Besides that a cantilever bridge has two or more towers that support all of the downward force. Also, the cantilever bridge is more stable, though most don’t cross more than a single span.
|
|
|
|
Still Can't Find What Your Looking For? Then Try a Essay Search!
|
