Transportation is key in today's society. It’s all about getting from one place to another in the quickest way possible. The inconvenience of going around something or going directly through can be tiring and can take up a lot of time. That’s where bridges come in. A bridge is a structure carrying a road, path or railroad across bodies of water, other roads or any object that may be an obstacle. Although there are many different types of bridges, they all deal with compressible and tensional stress. Each bridge has a certain way with enduring these stresses and each bridge can only hold a certain amount of weight before breaking. The four main types of bridges are: beam, arch, suspension and cantilever. The most commonly used bridge is the beam bridge. The beam bridge is made up of a horizontal structure and two or more vertical structures on either end for the horizontal structure to rest on. Beam bridges can be as simple as a fallen log across a river. In society, engineers generally make beam bridges out of steel and concrete.
Because beam bridges, or any bridge for that matter, are required to carry such heavy loads, engineers use trusses, to help distribute the weight. Trusses are generally made up of triangular or vertical shapes. These triangular or vertical shapes are very effective because a truss has the ability to dissipate a load through the truss work. A truss has the ability to transfer the load from on single point to a more spread out area.
The longest beam bridge is the Lake Pontchartrain Causeway in Louisiana. This bridge spans 24 miles, making it the longest bridge span over water in the world. The causeway was built in 1956 and is still in use to this day. The bridge consists of two lane railed surfaces 80 feet apart and is made up of prestressed panels which are supported by over 9000 concrete pilings. The Lake Pontchartrain Causeway proves that any structure is possible.
Suspension bridges are very similar to beam