A bridge bearing is a superstructure element that provides an in­ terface between the superstructure and the substructure. The three primary functions of a bridge bearing are:

• To transmit loads from the superstructure to the sub­ structure
• To allow rotation caused by dead load and live load deflec­ tion
• To permit horizontal movement of the superstructure due to thermal expansion and contraction (expansion bear­ ings only)

It is important to note that bridge bearings require proper maintenance, inspection and repair when needed, being the mechanical part of the bridge structure and as they need to maintain movement (translational or rotational) in the bridge structure at all times. Failure to do this could lead to malfunc­ tioning and failure of the bridge bearings , which could eventually lead to failure of the bridge struc­ ture itself if not repaired in due time. Usually life span of the bridge bearing is less than life span of the bridge itself.If the bridge bearing is not properly maintained it can fail even before its own life span.

Failure of the bridge bearing could consequently lead to failure of the bridge itself before its life span, hence the cost of putting the bearings in good conditions is high, but small compared to the cost of remedies for its failure