An isolation bearing for highway bridges using shape memory alloys

Conventional lead-rubber bearings may have a problem of instability and unrecovered deformation with a strong ground motion. As a way of solving the problem, this study proposes a new concept of an isolation device in which shape memory alloy wires are incorporated in an elastomeric bearing. A three-span continuous steel bridge was used for seismic analyses to compare the performance of lead-rubber and the proposed bearings. The proposed bearings limit the deck relative displacement effectively with strong ground motions and recover almost original undeformed shape.