A bridge is typically classified as a mass frame structure. A bridge is a structure designed to span an obstacle, such as a river or railway, allowing vehicles, pedestrians, and other loads to pass across. The prototypical bridge is quite simple—two supports holding up a beam—yet the engineering problems that must be overcome even in this simple form are inherent in every bridge: the supports must. Bridges are classified on the basis that how the four forces namely shear, compression, tension, and moment are distributed in the bridge structure. The function required from the bridge and the.