Study on seismic isolator using the thrust bearing

Abstract

The purposes of this study are to propose the seismic isolator which has the new characteristic using the thrust bearing, and to propose a simple method for the seismic isolation design. It is thought that the seismic isolator using the thrust bearing depends on the seismic input motion because it is nonlinear system with the geometric nonlinearity. Therefore, it is found that the response magnification changes with respect to the maximum acceleration of the seismic wave and the rotation spring constant, and the domain which has the response reduction effect on a response reduction map was acquired. It is thought that the proposed seismic isolator has the following characteristics from the analytical result. The initial state of the isolator is important in order to acquire the response reduction effect to the various excitation directions. The response reduction effect is small in the case of a long-period earthquake ground motion, and the seismic isolator carries out seismic isolation effect by making a rotation spring constant small. The response reduction effect is large in the case of a short period earthquake ground motion, and the rotation spring constant of the seismic isolator should be enlarged not to the response becomes unstable. Moreover, it is possible to make the seismic isolation design simply by applying the response reduction map.