Seismic Collapse Assessment of Composite Plate Shear Walls

Abstract

Collapse evaluation of composite plate shear walls (C-PSWs) under seismic loading requires a reliable analytical model that can accurately capture deterioration in the strength and stiffness of the system. In this study, research was carried out to develop a macromodeling approach for C-PSWs. Nonlinear time history analyses of six multistory (7-, 10-, and 13-story) C-PSWs (traditional and innovative) located in Western Canada were performed. It was observed that a significant portion of the story shear was resisted by the boundary members, while the RC panel resisted less than 10% of the total story shear. To estimate the seismic response parameters (i.e., ductility-related and overstrength-related force modification factors) for designing C-PSWs, incremental dynamic analysis (IDA) was performed for all archetypes following a standard procedure. It was observed that all archetypes provided significant safety margin against collapse (large collapse margin ratio). In addition, a sensitivity study was conducted and the effects of postyielding parameters (ductility capacity and postcapping stiffness) adopted for the deterioration model for infill plate and postcracking parameters (shear strain corresponding to maximum shear stress, yielding shear strain, and residual stress) adopted for the deterioration model for RC panel on seismic collapse capacities of traditional C-PSWs were investigated. It was observed that postyielding parameters for the steel infill plate can affect the seismic response of C-PSWs. On the other hand, variation of postcracking parameters for the concrete panel had a minor effect on seismic collapse capacity of the C-PSW system.