Economical laminated elastomeric bearings are well-adopted options for load transmission components of bridges from superstructure to substructure. In most cases, the design of such elastomeric bearings primarily depends on the requirements from service-level conditions such as superstructure thermal movements, with little consideration of extreme loads like earthquakes. However, bridge elastomeric bearings are very likely to be subjected to earthquake hazards, particularly for bridges located in high seismic regions. This study presents an overview of the observed typical damages of bridge elastomeric bearings in the past major earthquakes mainly in China and Japan. Comparisons of different damage patterns are conducted based on the different installations of bridge elastomeric bearings (bonding or un-bonding). The effect of bearing installation methods on the overall seismic behavior of bridges is also discussed. A desirable installation method for bridge elastomeric bearings against strong earthquake loads is recommended, which is expected to overcome the critical limitations of current design practice.

This study attempts to investigate the effect of the BRB distribution on the seismic performance of retrofitted multi-story RC tall bridge bents. Different BRB distributions were compared, from which the most efficient one was identified. The results showed that uniform distribution was not necessarily an efficient retrofit option. By controlling the same damage, using triangular cumulative distribution to design multi-story BRBs led to the least consumption of brace material. Alternatively speaking, with the same consumption of BRBs, the triangular cumulative distribution of braces was the most effective in controlling the damage of the tall bridge bents.