Suspension Bridge Essay Example for Free

Suspension Bridge Essay What is meant by suspension bridge? A suspension bridge is a type of bridge in which the deck (the load-bearing portion) is hung below suspension cables on vertical suspenders. Outside Tibet and Bhutan, where the first examples of this type of bridge were built in the 15th century, this type of bridge dates from the early 19th century. Bridges without vertical suspenders have a long history in many mountainous parts of the world. Structure of suspension bridge – This type of bridge has cables suspended between towers, plus vertical suspender cables that carry the weight of the deck below, upon which traffic crosses. This arrangement allows the deck to be level or to arc upward for additional clearance. Like other suspension bridge types, this type often is constructed without false work. Can a suspension bridge be considered as a work on parabola? Yes, a suspension bridge can be called a work on parabola. As a suspension bridge is designed on parabola as the bridge is also in the â€Å"U† shaped figure as we can see it in our project. Parabola is a curved conical shaped open figure. Parabola can be defined in different ways. First, it is the graph of any quadratic function of the form y = ax2 + bx + c. Another way though, is to define it as the collection of all points that are equidistant from a line and a point not on the line. A parabola is a curve, much like a U shape. The most simple parabola is y = x^2. More info about parabola   and suspension bridge Some facts about parabola and suspension bridge:- The vertical line passing through the vertex is called the axis of symmetry. The eq. for the line is where D=0 Quadratic formula if ax2 + bx + c = 0 then x=-b ±b2-4ac2a Basic design of parabolic bridge:- Dutch scientist Christian Huygens believed that two cables running between two towers could support weight that was much greater than its own weight. The cables suspended between the two towers naturally took the shape of a parabola. The parabolic shape of the cable is created not only by gravity but also by the compression and tension forces acting on the bridge. Todays scientists believe that this is the most efficient design because it requires the least amount of materials to support a heavy load. The modern suspension bridge is composed of a deck, supports, foundations, long wire cables and hangers. Latest Research on Suspension Bridges:- Research on structural topology optimization on a suspension bridges parabolic cable has shown that it is possible to increase its capacity to withstand compressive forces. In order to help stabilize suspension bridges, truss systems are used. The truss system helps the deck resist bending, twisting and swaying. DO you KNOW: The longest suspension bridge in the world (as of 2010) is the Akashi Kaikyo Bridge in Kobe, Japan. It opened in 1998 and spans an incredible 1991 meters (6529 feet) Suspension Bridges Design technology Suspension bridges in their simplest form were originally made from rope and wood. Modern suspension bridges use a box section roadway supported by high tensile strength cables. In the early nineteenth century, suspension bridges used iron chains for cables. The high tensile cables used in most modern suspension bridges were introduced in the late nineteenth century. Today, the cables are made of thousands of individual steel wires bound tightly together. Steel, which is very strong under tension, is an ideal material for cables; a single steel wire, only 0.1 inch thick, can support over half a ton without breaking. Light, and strong, suspension bridges can span distances from 2,000 to 7,000 feet far longer than any other kind of bridge. They are ideal for covering busy waterways. With any bridge project the choice of materials and form usually comes down to cost. Suspension bridges tend to be the most expensive to build. A suspension bridge suspends the roadway from huge main cables, which extend from one end of the bridge to the other. These cables rest on top of high towers and have to be securely anchored into the bank at either end of the bridge. The towers enable the main cables to be draped over long distances. Most of the weight or load of the bridge is transferred by the cables to the anchorage systems. These are imbedded in either solid rock or huge concrete blocks. Inside the anchorages, the cables are spread over a large area to evenly distribute the load and to prevent the cables from breaking free. Suspension bridge: construction that allows automobiles to travel between two points separated by an obstacle. Side span: segment between two pylons at the ends of a bridge. Centre span: segment between two pylons at the centre of a bridge. Side pylon: tower-like vertical construction situated at the side, usually supporting the cables of a suspension bridge or a cable-stayed bridge. Foundation of a pylon: very durable lower part of a tower. Suspender: support cable. Suspension cable: set of braided wire that supports a bridge. Pylon: tower-like vertical support that usually supports the cables of a suspension bridge or a cable-stayed bridge. Stiffening girder: tightener beam