Abstract

Unstiffened steel plate shear wall (SPSW) is considered as a primary lateral load resisting system due to its significant post-buckling strength, high ductility, stable hysteretic behaviors and robust initial stiffness. Nonlinear seismic analysis can accurately estimate structural responses, however, the method is very time consuming and may not be suitable for regular engineering practice. On the other hand, traditional pushover analysis method does not consider contributions of higher modes to the structural responses and thus, often do not provide good estimation of seismic responses for taller buildings. Capacity-Spectrum Method (CSM) and modal pushover analysis (MPA) are two simple nonlinear static methods that have been proposed and recently used for seismic performance evaluation of few lateral load-resisting systems. This research further examines the applicability of CSM and MPA methods to assess seismic performance of steel plate shear walls. A nonlinear finite element model was developed and validated with experimental studies. Three different SPSWs (4-, 8-, and 15-storey) designed according to capacity design approach were analysed by subjecting the steel shear walls under artificial and real ground motions for Vancouver. The CSM and MPA procedures were applied to analyse the selected SPSWs and the results were compared with more accurate nonlinear seismic analysis results. It is observed that both CSM and MPA procedures can reasonably predict the peak roof displacements for low-rise SPSW buildings. In addition, MPA procedure, which includes contributions of higher modes when estimating seismic demands of buildings, provides better predictions of critical seismic response parameters for taller SPSWs.