Semiactive Seismic Isolation System Using Controllable Friction Damper (2nd Report, Study of the System with Distributed Controllable Friction Dampers)

Abstract

A semiactive seismic isolation system with distributed controllable friction dampers was studied, in which the damping force was controlled by varying the pressure between the friction elemens. Excitation tests were carried out for a base-isolated single-story building model supported by 4 rubber bearings and equipped with 2 controllable friction dampers on the bottom. The tests showed that the semiactive isolation system was equal or superior to normal passive seismic isolation systems in response acceleration reduction, and that the semiactive system could reduce the response displacement significantly, as compared with the passive system. The tests also showed that the small rotational response of the builiding model was induced by fluctuation in the small pressures of the friction dampers which was caused by their mechanism. However, simulation studies showed that the large rotational response could be controlled and reduced by the distributed dampers.