Experiment of Ultimate Shear Failure and Friction Sliding Performance of Rubber Bearings of Bridges

Abstract

Introduction: To fully ascertain the ultimate shear failure state and friction sliding performance of laminated rubber bearings used in bridges, a series of cyclic loading tests on such laminated rubber bearings was conducted. Method: The energy dissipation characteristics of rubber bearings with two fixed end plates, rubber bearings with unilateral friction sliding and a lead rubber bearing (LRB) under a low-frequency cyclic load were compared and analyzed. Results and conclusion: The results showed that (1) the ultimate shear deformation of the rubber bearings with two fixed end plates reached 300% to 400% of the rubber layer thickness. The damage was mainly focused on the rubber layer fracture. The energy dissipation capacity of the bearings was weak, and the hysteresis curve presented a narrow zonal shape. (2) The rubber bearings with unilateral friction sliding had a similar energy dissipation capacity compared to the LRB. The maximum energy dissipation in a single cycle could reach 126% of the LRB’s maximum energy dissipation. With an increase in the sliding distance, the dissipated energy continuously increased. The shear deformation of the bearing no longer increased after reaching its maximum. After the test, the bearings remained in good condition. The hysteresis curves of load-displacement presented a bilinear shape. (3) Under cyclic loading, the energy dissipation capacity of LRBs was stable. The LRBs played an effective role in energy dissipation during loading. After the test, the LRBs nearly returned to their original condition. The hysteresis curves of LRB were always fuller than the laminated rubber bearings.