Effect of Lead Core Heating on Residual Displacements of Lead Rubber Bearings Under Bi-Directional Earthquake Excitations

This paper investigates the variation in residual displacements (RDs) of lead rubber bearings (LRBs) subjected to bi-directional earthquake excitations when lead core heating effect is of concern. Accordingly, several dynamic analyses were conducted considering isolator response with and without lead core heating effect. A wide range of isolation system properties, several characteristic strength to weight ratios, isolation periods and yield displacements were considered to construct the bi-linear force-displacement relations of LRBs. Ground motions were selected to represent different magnitudes and pulse characteristics. Results were also used to assess the efficacy of code suggested equations to estimate RDs of seismic isolators.