EVALUATION OF SEISMIC PERFORMANCE OF UPSS IN TERMS OF ENERGY DISSIPATION CONSIDERING NONLINEAR PIER RESPONSE

Abstract

 UPSS (Uplifting Slide Shoe) is a kind of sliding bearing which is combined with a horizontal plane and inclined planes on both sides. The seismic energy is dissipated by the sliding friction, the structural damping and the hysreresis energy dissiation of the pier. In this paper, influence of the inclined angle, the friction coefficient of UPSS and the yielding load of the pier to the seismic behavior is investigated. As a result, it is confirmed that there is a trade-off relationship between the displacement of UPSS and the response ductility factor of the pier. Namely, it is observed that the larger the inclined angle, the shorter the UPSS displacement and the greater the absorved energy of the pier. The reason is that the seismic behavior changes heavily depending on the response period for each ground type. This finding can be used to design appropriate UPSS configration based on the target seismic behavior.