EVALUATION OF EQUIVALENT LINEARIZATION ANALYSIS METHODS FOR SEISMICALLY ISOLATED BUILDING USING LEAD-RUBBER BEARING

Abstract

The paper presents an evaluation of the linearization analysis method for isolated multi-story building structures using lead-rubber bearings (LRB) considering vertical stiffness and critical buckling load. The effective linear parameters of LRB are estimated by the single-mode spectral analysis method, calculating for a typical target spectrum by TCVN 9386:2012. A set of time history analyses is conducted on both the equivalent linear model and the bilinear model. A comparison of seismic responses between the two models is performed where the bilinear model included considering the effects of vertical stiffness and critical buckling load. The results show the conservative design in force and displacement of the isolated structure by the linearization analysis method, but non-conservative design in floor accelerations. Significantly higher displacement estimates by the linearization method may lead to over-designed bearing displacement capacity.