Earthquake response and isolation effect analysis for separation type three-dimensional isolated structure

Abstract

This study proposes a design method for separation type three-dimensional isolated structure in which the horizontal and vertical isolation layers are separated for decoupling purpose. In this system, multiple guide rails are used vertically to limit the lateral displacements of upper structure while providing adequate overturning moment resistance. In this paper, a general formulation was proposed firstly to define two critical parameters, i.e., the rotation coefficient and the rotational displacement coefficient, the latter of which correlates the rotation-induced displacement and the total horizontal displacement. Subsequently, a separation type three-dimensional isolated structure model using the proposed method was established to evaluate its isolation effect through shaking table test, and a similar non-isolated structure model was also tested for comparison purpose. An analytical model was established for comparison to the experimental results. Experimental results show that the acceleration responses of the separation type three-dimensional isolated structure model are much less than the non-isolated model in both horizontal and vertical direction, demonstrating a desirable isolation effect for the isolated structure. In the meantime, the vertical guide rails benefits significantly to the overturning moment resistance.