Ultimate shear performance and friction sliding response of laminated elastomeric bridge bearings

In major earthquakes, friction sliding of common laminated elastomeric bearings limits the force transmitted from the superstructure to the substructure. Experiments were carried out to investigate the ultimate shear performance and the friction sliding response of laminated elastomeric bridge bearings. First, the hysteresis curve of the common laminated elastomeric bearings present narrow ribbon which meant the energy dissipation capacity induced by the shear deformation was weak. The ultimate shear deformation of the bearings could reach 300 % to 400 % of the elastomeric thickness. The damage of bearings was mainly focused on the rubber layer fracture. Second, the energy dissipation capacity of elastomeric bearings induced by the friction sliding was larger than the shear deformation, and was similar with the lead rubber bearing. Since the total displacement include both elastomer shear deformation and sliding components, the dissipated energy continuously increased with the increasing of the sliding distance. When the tests finished, the bearings were basic intact, only the rubber surface was worn down. Last, the bilinear elastic-plastic model is proposed to take as the theoretical model of the elastomeric bearing with friction sliding for the research and design of bridge in earthquake.