Overturning Resistance of Friction Pendulum Bearing-Isolated Structure Subjected to Impact

Abstract

Friction pendulum bearing (FPB) shows superior performance in reducing dynamic responses of structures under earthquakes. Though the seismic response of the FPB-isolated structure is well understood, its overturning resistance caused by limited permissible displacement under impact is rarely studied. This paper presents an evaluation and parametric study on the overturning resistance of the FPB-isolated structure under impact, using particularly the coefficient of overturning resistance to evaluate the overturning resistance of the isolated structure. The capacity of the overturning resistance of FPB-isolated structure as well as the seismic response when the isolated structure subjected to pluse-like and no-pluse-like earthquake records were addressed. The influence of various key factors, including the vertical component of impact force, displacement ratio, properties of the FPB, peak ground acceleration (PGA), and mass ratio of the isolation storey, is investigated to give an insight into the potential overturning risk of the entire structure. The results indicate that the overturning resistance of the FPB-isolated structure will be reduced significantly due to the presence of impact. The overturning stability depends mainly on the displacement ratio, impact stiffness, PGA, friction coefficient, and equivalent radius of the FPB, but the mass ratio of the isolation storey shows limited influence on the overturning resistance of the FPB-isolated structure under impact.