BRIDGES



Bridges are a type of structure that spans horizontally to create a passage over a river, valley or any other obstacle.

The design of a bridge depends on the function of it (trains, pedestrian, road traffic, pipeline for water transport or barge traffic) and on the nature of the terrain where it is going to be constructed. The design and construction of a bridge it is very difficult and delicate thing to do, and requires a lot of engineering knowledge. For example the resonance vibration (“tendency of a system to oscillate at larger amplitude at some frequencies than al others”) is such an important thing in a bridge that if exist just one mistake in the math the bridge probably will fall down, an example of this is the Tacoma Bridge in 1940 that fell down after an hour of resonance. In this video you will see the entire event.

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There are about six main types of bridges.

Beam Bridges: horizontal beams supported at each end by piers.

Cantilever bridges: horizontal beams that are supported on only one end.

Arch Bridge: arch-shaped and have abutments at each end.

Suspension Bridge: suspended from cables. The cables hang from towers that are attached to caissons or cofferdams.

Cable-stayed Bridges: also are help out by cables but the towers are shorter and the cables required are less than the suspension bridge.

Truss Bridge: compose of connected elements. They have solid deck and a lattice of pin-joined or gusset-joined for the sides.

Double-decker Bridge is a variation of bridges that basically the difference is that has two levels.

The material use in the construction of bridges depends on the use and on the span of the bridge, there are bridges made of stone, wood and steel, the most common material is steel because can be use for bigger and largest bridges.

Bridges are very efficient ways to communicate to places because make the communication faster and accessible for any person without the necessity of using for example a plane or a ferry.

These are some structures of bridges: