Types of Bridges Essay
Beam - The beam type is the simplest type of bridge. The beam bridge could be anything as simple as a plank of wood to a complex structure. It is made of two or more supports which hold up a beam.
Arch - In the arch type of bridge, weight is carried outward along two paths, curving toward the ground.
Suspension/Cable-stayed - The deck (trafficway) of a suspension bridge is hung by cables which hang from towers. The cables transfer the weight to the towers, which transfer the weight to the ground.
Cable-stayed bridges have towers, but cables from the towers go directly to the road deck, instead of spanning from …show more content…
For simple spans up to 25m and continuous spans up to 33m, rolled universal beams are economic and are available up to 1000mm deep. Very little fabrication is required, usually only the fitting of stiffeners for bearings & the attachment of bracing, and sections may be bent to provide precamber and horizontal curvature.
For longer span bridges, deeper girders are fabricated from plates. This gives scope to vary the web and flange sizes and the steel grades for an efficient design. Variable depth girders are often used to give greater economy, and also to enhance aesthetics. Such plate girders can be readily fabricated with curvature in plan and elevation.
Box girder bridges
Box girders are a particular form of plate girder, with two webs joined by common top and bottom flanges. Boxes may be used either singly or in multiples. They may be straight or curved in plan and be of constant or variable depth. If using a concrete top flange then the box girder is called "open top". Box girders with a steel top flange (often called an ‘orthotropic deck’) will give a minimum weight