Fundamental Study of Earthquake Isolation Systems Suitable for Buildings of Industrial Facilities : 2nd Report, Performance of Earthquake Isolation Systems Using Viscous Dampers

Abstract

Earthquake isolation systems for industrial facilities should perform satisfactorily not only for the buildings but also for the internal equipment. From this point of view, earthquake isolation systems using laminated rubber bearings and various types of energy absorbing devices have been evaluated through experimental tests of a 0.3 scale model of a two-storey steel-frame building and theoretical analysis, to find the most suitable systems for industrial facilities. The performance of two types of isolation systems using oil dampers and viscous shear dampers, being representative of viscous damper, respectively was examined. Both systems using these viscous dampers could not only reduce the response accelerations of the building itself but also remarkably attenuate the response of the internal equipment. However neither system, particularly the system using oil dampers, seemed to be suitable to earthquake of having lower dominant frequencies such as Akita NS ground motion record because the deflexion of rubber bearings was not adequately limited.