title: Elastomeric bridge bearing
text: # Elastomeric bridge bearing
  
  An elastomeric bridge bearing, also known as a pot bearing or elastomeric bearing, is a commonly used modern bridge bearing. The term encompasses several different types of bearings including bearing pads, bridge bearings, laminated elastomeric bearings, and seismic isolators ... which are all generally referred to as "bridge bearing pads" in the construction industry.
  
  The purpose of the elastomeric bearings is to support a bridge or other heavy structure in a way that permits the load to shift slightly, in a horizontal direction, relative to the ground or foundation. Without such bearings, the bridge support might crack or fracture when it moves due to ground movements or thermal expansion and contraction. Elastomeric bearing pads compress on vertical load and accommodate both horizontal rotation and horizontal shear movement.
  
  The internal structure of an elastomeric bearing consists of a three layers: a lower "pot" made of steel, which rests on the foundation or footing; a relatively thin elastomeric pad (a rectangle or disk shape) resting on the lower pot; and a steel plate loosely set on top of the elastomeric disk, on top of which the weight of the bridge rests. The bearings are often produced as a unit, ready to be installed.
  
  The elastomeric pad may made from any of several materials, including natural rubber, elastomers, teflon, or synthetic rubber (such as neoprene).
  
  Elastomeric bearing pads are the most economical solution used in construction of large span bridges and buildings.
  
  Elastomeric bearings are often used in applications other than bridges, for example, supporting buildings that are built on soil that may shift slightly and cause a concrete load to crack in the absence of a elastomeric bearing.
  
  Elastomeric bearings are designed and manufactured based on standards and specifications of such organizations as British Standard, AASHTO, and European Norms En 1337.
  
  