A bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle. Designs of bridges vary depending on the function of the bridge, the nature of the terrain where the bridge is constructed, the material used to make it and the funds available to build it.
Beam bridges are horizontal beams supported at each end by abutments, hence their structural name of simply supported. When there is more than one span the intermediate supports are known as piers. The earliest beam bridges were simple logs that sat across streams and similar simple structures. In modern times, beam bridges are large box steel girder bridges. Weight on top of the beam pushes straight down on the abutments at either end of the bridge. They are made up mostly of metal, concrete or wood. Beam bridge spans typically do not exceed 250 feet (76 m) long, as the strength of a span decreases with increased length. However, the main span of the Rio-Niteroi Bridge, a box girder bridge, is 300 metres (980 ft). The world’s longest beam bridge is Lake Pontchartrain Causeway in southern Louisiana in the United States, at 23.83 miles (38.35 km), with individual spans of 56 feet (17 m).
DESIGNED BRIDGE (View plotted project)
Designed bridge is a beam bridge made of prestressed concrete. It has three spans, two lateral span 20 meters long and a central span 30 meters long.
The bridge seismic isolated with elastomeric system. Great attention was given to the design and modelling of the isolation system. Were also designed the prestressing and constructional method.
The model and the study of the bridge was made with the software SAP 2000.