Horizontal response of base-isolated buildings supported to high damping rubber bearings

Seismic isolation is one of the most efficient techniques to protect structures against earthquakes. Rubber bearings are suitable for low-rise and medium-rise buildings due to its durability and easy fabrication. This paper presents the horizontal response of a six-storey base-isolated building using high damping rubber bearings (HDRBs) under two ground motions of earthquakes as types I and II in JRA (2002) by finite element analysis. In this analysis, these bearings are modelled by the bilinear hysteretic model which is indicated in JRA and AASHTO. Comparison of horizontal response including base shear force and roof level acceleration between the two cases: base-isolated building and fixed-base building is carried out to evaluate the effectiveness of the use of HDRBs on the protection of buildings from earthquakes. The numerical results show that the peak value of roof floor acceleration of the fixed-base building is two times higher than that of the base-isolated building, and the floor accelerations depend on the peak values of ground acceleration. In addition, the step-by-step design procedure for determining the size of HDRBs used for buildings is also presented in this paper.