Construction of Bridges
A bridge is a structure that spans a depression or provides a passage between two points which are at a height above the ground affording a passage for pedestrians, vehicles, and also built to span a valley, road, body of water, or other physical obstacle, for the purpose of providing passage over the obstacle. Designs of bridges vary depending on the function of the bridge and the nature of the terrain where the bridge is constructed. It is one thing to design a bridge. It is another thing to build it. Planning and executing the construction of a bridge is often very complicated, and in fact may be the most ingenious (ingénieur - engineer) parts of the entire enterprise. An incomplete structure is often subjected to stresses and oscillations that would not arise after completion. The construction work is potentially a grave hindrance to existing traffic and to normal life in the area, especially when large local fabrication works have to be installed. Even before any actual const...