Seismic isolation effects of laminated rubber bearing paced with granular material

A great attention has been paid to seismically isolated structures since the Hyogo-Ken Nanbu Earthquake in 1995. A laminated rubber bearing, which consists of a laminated rubber cylindrical outer shell and granular material packed in it, was newly developed in this study. Its fundamental mechanical characteristics on vibration and the validity for practical use were examined through element tests, shaking table tests and vibration analysis of one degree of freedom system. The results of element tests have showed that the laminated rubber bearing packed with granular materials can have much energy absorption due to the effect of contact friction and that of dilatancy between solid particles. Also presented in the vibration analysis is the fact that the calculated values of response acceleration of a house model have a close correlation to those given in the shaking table tests