Analysis of Seismic Performance of a Unseating-prevention Laminated Rubber Bearing

A unseating-prevention laminated rubber bearing(URB) was developed to solve the problem that girder falling might be caused by the failure of laminated rubber bearing(RB). Based on introduction of URB,seismic analysis of a typical precast bridge with URB in the high-intensity seismic zone under rare earthquake was done and parameters of URB were studied afterwards.Resultsshow that relative displacement between the superstructure and the substructure of the bridge can be controlled by wire rope of URB to protect the bearings and reduce the risk of girder falling; although seismic response of pier can be increased by URB,this adverse effects can still be reduced by adjusting parameters of the wire rope; initial gap and tensile stiffness of the wire rope are basic parameters of URB,where the former should meet the demands of normal using and earthquake,and the later can be determined by considering seismic response of URB and the pier together.