Survey on Types Damage Caused by Earthquakes in Bridges

Earthquake damage to a bridge can have server consequences. Clearly¡ the collapse of a bridge places people on or below the bridge at risk¡ and it must be replaced after the earthquake unless alternative transportation paths are identified. The consequences of less server damage are less obvious and dramatic¡ but they are nonetheless important. A bridge closure¡ even if it is temporary¡ can have tremendous consequences¡ because bridge often provides vital links in a transportation system. In the immediate aftermath of an earthquake¡ closure of a bridge can impair emergency response operations. Later¡ the economic impact of a bridge closure increases with the length of time the bridge is closed¡ the economic importance of the traffic using the route¡ the traffic delay caused by following alternative routes¡ and the replacement cost for the bridge. The purpose of this paper is to identify and classify types of damage to bridges that earthquake commonly induce and¡ where possible¡ to identify the causes of the damage. This task is not straightforward. Damage usually results from a complex and interacting set of contributing variables. The details of damage are often obscured by the damage itself¡ so that some speculation is required in reconstructing the event. In many cases¡ the cause of damage can be understood only after detailed analysis¡ and even then¡ the actual causes and effects may be elusive.