Different Types of Bridges Essay

A considerable obstacle to the Legions was the number of small rivers and streams. Gradually, the legions became better at engineering, until every soldier was able to complete his part of a simple pontoon bridge, as shown here: Also taken from Trajan's column. These pontoon bridges were constructed from boats, over which planking was laid. When horses were required to cross, a small layer of earth was sometimes put on the bridge, to reassure them. Stone Roman bridges remain famous for their durability to this day, and their three or four arches was a roman concept, so that weight on the top of the bridge merely forced the keystones of the

continued to travel across the bridge for 250 centuries. It is thought that the first

A simple beam bridge that is flat across and supported at the two ends. A longer beam bridge can be held up along the middle by piers standing in the river. The weight of the bridge itself, plus the load that it carries, plus gravity are the downward forces are spread evenly across the length of the bridge. The upwards forces that hold the bridge up come from the piers. The Confederation Bridge in Canada is a famous beam bridge.

The first completed steel bridge was the Eads Bridge, in St. Louis Missouri. Steel was a very new material and was just starting to become commercially available. Steel was a smart choice to use because it is extremely hard and resists rusting. The Eads Bridge was the longest arch bridge in the world, of 510 feet long. St. Louis became a very important city in the midwest and had to really compete with Chicago during the Civil War. After the Civil War, St. Louis started growing in all directions. “.... the city of St. Louis wanted to reestablish its prewar dominance as the economic powerhouse of the midwest” (Ostrow 75). The main reason to build the Eads Bridge was to connect settlers from the East to the lands of the West. At the time there

In the small town of Waco, Texas who would have thought it was once well known for the structure of a bridge, the Waco Suspension Bridge to be exact. Up until 1870, the Brazos River was just a simple river that had no special meaning to it. The land around it was empty, occasionally you would find cattlemen pushing their cattle across stream, but that was only because you could not find one bridge that spanned the eight hundred miles of river flowing through Central Texas. This caused a serious transportation issue for merchants and travelers. It became clear that a better means of crossing the river was necessary.

In the middle of nowhere, in that vast expanse of trees, lies The Bridge. Nobody knows it as any other name. It stretches across the Dead River, just sitting there waiting for someone new to find it. At one time it was driven over constantly, a way of travel for the inhabitants who are crazy enough to live out there. But now it is just there, a giant chunk of metal, rusting away into nothing. Occasionally it is used for things like fishing, or as a

The first example of an external force is the static (dead) load, this refers to the gravitational forces acting on the bridge itself. Every structure has to be able to support the weight of its own materials in order for it not to collapse, this is before any live load is applied to it. Another example is dynamic (live) load which refers to traffic, from people or vehicles, which move across the bridge and apply additional weight to it increasing the magnitude of vertical forces acting on the bridge. But environmental factors such as changes in temperature, precipitation and winds can also create vertical and horizontal loads on the bridge. (Bagga

Initially, suspension bridges before 1940 were made of piers, towers, wires, anchorages, and roadways. Piers were the main foundation for the suspension bridges. There usually were two of them, which were made out of cement and were entrenched in ground underneath the body of water that the bridge was spanned across. Towers were built on top of the piers to provide a means of connection for the roadways and wires. Wires were connected to the towers, roadways, and anchorages to provide tension support for the weight of the bridge. The anchorages were large cement platforms that were planted into the ground on either side of the land so that the wires could be connected to it. Lastly, the roadways were the main point of the suspension bridge. They usually were wide enough to provide four lanes of traffic and stretched from one side of the bridge to the other. This was the basic design of the suspension bridges

The Romans were the first builders in Europe, perhaps the first in the world, to fully appreciate the advantages of the arch, the vault and the dome (Cartwright, 2013). The Romans are credited with creating arches because they used them so often and in extremely large structures. Most people have heard of the Roman

For smaller spans, the Inca simply laid out a large stone. For large gaps, however, stones were not long enough, so they made bridges out of the most abundant material they had: grass. They wove together long fibers to form thick ropes. These ropes were then used to create the floor and guide ropes. Although they sagged deeply and were at times unstable, the bridges were very safe because of a permanent attendant, who was there “not only to service the ropes but to help travelers and caravans cross” (Isbell n.p.). They were also able to hold up a large amount of weight. According to a study by John Ochsendorf, a professor at MIT, “the bridge's main cables [could] support 16,000 pounds, and he believes the cables of the sturdiest Incan bridges, incorporating leather, vines and branches, could have supported 200,000 pounds.” (Clough 8). The bridges were not difficult to create, and some communities even developed an annual ritual to cut down the bridge, let it flow down the river, and then construct a new

Structurally, the bridge is a composition of two key metals steel (2 x 1011 Nm-2) and aluminum. These metals are common in bridges due to their properties of high strength and

The Pratt truss bridge was originally founded by Caleb and Thomas Pratt in 1844. It is mainly used to carry trains. The biggest advantage of this bridge was its low costs for construction and the materials to construct a truss bridge are minimal. It also use materials that is cheaper and light in weight. We can easily identify a pratt truss by detecting its diagonal members, which (excluding for the very end ones) all slant down and in toward the center of the span. The pratt truss was designed by applying few laws that related to the mechanics of materials concept. The bridge is mainly built using steel girders to support the construction of the structure. The below part of bridge weight is high so, it need an enough support to prevent from

It is shaped in a way to transfer weight to the towers and anchors with its tension (O'Connor, 1971, p. 372). Cables are made of high strength wires spirally bound to form a rope (O'Connor, 1971, p. 372). Vertical cable suspenders that are fastened to the main cables hang the actual roadway. Stiffening girders and trusses are along the side of the bridge to distribute concentrated loads and help to keep the motion of the bridge at a minimum (Troitsky, 1994, p115).

A bridge is a structure providing path over an obstacle. When constructing a bridge, obstacle can be a river, railway track or a valley and the path provided by bridge can be for a road, pedestrians, a railway, pipelines, viaducts to carry water from rich areas to dry cities, or for commercial purpose to host commercial buildings such as restaurants and shops. A bridge can also be laid to reduce the distance of travel which in turn reduces the time to reach the destination.

bridges: the Vasco da Gama bridge in Lisbon (Portugal) and the Rion-Antirion bridge, near Patras