The three most basic types of bridges are beam, arch, and suspension bridges. These three bridges differ in things such as design and length, and they are used all around the world in order to connect us to our surroundings.
The arch bridge is a semicircular structure that diverts the weight from the bridge deck to one of two abutments on each end. The larger the degree of curvature, the more tension is placed upon the underside. Its structure distributes compression onto the abutments which directly take on any pressure. Something tricky to building the arch is that the two converging parts of the structure have no structural integrity until they meet in the middle. so often additional scaffolding and support systems are needed. Modern materials such as steel and concrete allow us to
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The weight of the bridge and any traffic on it is directly supported by the piers. Many beam bridges that you find on highway overpasses use concrete or steel beams to handle the load. The size of the beam, especially the height, determines the distance that the beam can span. By increasing the height of the beam, the beam has more material to dissipate the tension. To create tall beams, bridge designers add supporting lattice work (truss) to the bridge's beam. As the distance increases, the size of the truss must also increase, until it reaches a point where the bridge's own weight is so large that the truss cannot support it. The design of a truss creates a rigid structure as well as transfers the load from a single point to a much wider area. The very top of the beam gets the most compression, and the very bottom of the beam experiences the most tension. The middle of the beam experiences very little compression or tension. The weight of the beam pushes straight down on the piers. The farther apart its piers, the weaker the beam becomes. For this reason, bridges rarely span more than 250