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Abstract
A Bridge is a structure built to span a valley, road, river, body of water, or any other physical obstacle. Designs of Bridges will vary depending upon the function of the bridge and nature of the area where the bridge is to be constructed. The first bridges were made by nature itself assimple as a log fallen across a stream or stones in the river. The first bridges made by humans were probably spans of cut wooden logs or planks and eventually stones, using a simple support and crossbeam arrangement. Some early Indians used trees or bamboo poles to cross small caverns or wells to get from one place to another. A common form of lashing sticks, logs, and deciduous branches together involved the use of long reeds or other harvested fibres woven together to form a connective rope capable of binding and holding together the materials used in early bridges. Hilly region pose unique problem for bridge construction. In a restricted hilly areaitself climatic conditions, geological features and hydrological parameters vary considerably.Keeping in view the bridge site and various constraints, type of bridge and method ofconstruction are to be selected carefully for safe, economical and successful completion of bridgeconstruction. India, a country with a total area of approx. 3.2 million sq. km. has around 23 % ofits area covered with densely forested, thinly populated hills. Human habitation and Vegetationspreads to altitudes as high as 14000 to 16000 feet above Mean Sea Level.