Overturning Resistance of Structure Base-Isolated by Laminated Rubber Bearing Considering Pounding Against the Moat Wall

Abstract

The overturning resistance of structures base-isolated using laminated rubber bearings (LRBs) is crucial to the stability of the structure due to the poor tensile performance of LRBs. Pounding occurs between the structure and moat wall, which can result in a reduction of the overturning resistance of the structure. This study aims to investigate the overturning resistance of a structure base-isolated by LRBs considering pounding against the moat wall based on numerical simulations. The influence of the gap size, pounding stiffness, and the horizontal stiffness of the isolation storey on the overturning resistance of the isolated structure was evaluated through parameter studies. The results indicate that poundings between the structure and moat wall result in short but large pounding forces. Pounding forces would amplify acceleration, inter-storey drifts of the isolated structure, and significantly increase the risk of overturning of the isolated structure. Increasing the gap ratio can improve the seismic performance of the structure. Larger pounding stiffness leads to greater pounding forces generated by the structure, and the risk of overturning of the structure increases. The coefficient of overturning resistance initially decreases, and then increases, as the stiffness of the isolation storey increases.