Bridge Designs

The architectural structure of bridges are unique and possess their own terms, styles and components. To describe a bridge, there are four main factors that are used and by combining these terms, you will gain a better knowledge as to what types of bridge structure there are. There are 4 types of bridge designs that exist, which includes arch, truss (also known as beam), cantilever and suspension. A well-known type of temporary bridge is the pontoon bridge. It is used to cross rivers and larger bodies of water, while pontoons are the weight of the bridge is that is supported on floating structures. Read More

With a long history of Pontoon bridges that are used for military use, Alexander the Great is known to have crossed the Oxus River that is located in central Asian by using a bridge that is constructed of floating pontoons made from his soldier’s tents.

Arch Bridges

The arch type of bridges are known to be the oldest design of bridges as they are constructed with both wood and stone and displays a clever design that transfers the weight of the traffic on the bridge with support on opposite ends – known as abutments. Many of the historical bridges are built in this design, including the famous Pont de Gard aqueduct that is located near Nimes in France. The 3-tier Roman-built structure is said to be over 2,000 years old as it stands 164 feet high. UNESCO has designated the structure as a World Heritage site in 2007.

Truss Bridges

The truss or beam bridge is the most basic kind as it consists of horizontal beams that is supported by vertical piers. The simplicity of beam bridges are appropriate for short distances as they rarely cover more than 250 feet of distance. The bridge of Lake Pontachartrain Causeway in Louisiana is also considered as the world’s longest over-water bridge as it is 24 miles long with 2,243 separate spans.

Cantilever Bridges

By the invention of German engineer Heinrich Gerber, Cantilever bridges were made possible in 1866. Unlike many of the previous inventions, the hew girder was able to support the heavy stress involved in supported a large bridge and sustain their weight through rigid supports on both ends. Gerber himself looked over the construction of the very first cantilever bridge in 1887, though was made famous from the Forth Railway Bridge in Scotland. This was also the first time a bridge was constructed with steel. The bridge was 1.5 miles long and made up of 3 double cantilevers that are linked with 345 ft. long steel girder spans.

Suspension Bridges

Suspensions bridges are designed to support the weight using pairs of cables that cohesively link vertically to control with anchors on both ends. This design allows the bridge to expand farther than an arch or Beam Bridge would. One of the most famous suspension bridges in the Gold Gate Bridge in San Francisco, California that runs 1.7 miles long. It was built with a massive construction and weight approximately 887,000 tons as each anchorage weights 60,000 tons alone.