Nonlinear response of seismically isolated steel buildings

Abstract

The results of nonlinear earthquake time history analyses of seismically-isolated buildings are presented in this report. A computer program called DRA.IN-2DX is used to analyse two types of lateral-force-resisting systems, a four-storey momentframe and a four-storey braced-frame. Four isolation systems for each building type are modelled and evaluated using several earthquake records. Peak displacements in the isolation system and peak displacements in the top floor of the superstructure are calculated for each building analysed. Ductility demands for each isolated building are calculated and compared with-those of the fixed-base structure of the same type of building.