A hybrid sliding isolation system for bridges

ABSTRACT

This study deals with a hybrid isolation system using friction controllable sliding bearings. During earthquakes, this isolation system controls the friction force on the sliding interface between the structure and the ground to confine the aliding displacement within an acceptable range, while keeping the transfer of seismic force to a minimum. This is the advantage of the hybrid sliding isolation system that can not be duplicated by the passive sliding system. Instantaneous optimal control and bang-bang control algorithms are developed for controlling the friction force. Shaking table tests are perfomed using a bridge model equipped with such a hybrid isolation system. Computer simulations show good agreement with the experimental results, demonstrating the effectiveness of the hybrid sliding control system and the feasibility of its applications for bridges.(AU)