ABSTRACT
Design equations are presented for estimating the bearing deflection and superstructure drifts for isolated buildings in the elastic regime from the response spectrum. For stronger excitations the post-yield drift is concentrated in the first storey and an equation for estimating is also given. The predictions of the equations are compared to time-history calculations of response of stick models of five different superstructures, either fixed-base, with a linear isolation system or with a more realistic non-linear model for an isolation system based on rubber in shear. The responses with the non-linear isolation system are not very different from those of the linear system, and the design equations for elastic response are in good agreement with the numerical calculations; the agreement is fair in the case of post-yield drift.
