Seismic demand of moderately ductile reinforced concrete shear walls subjected to high-frequency ground motions

Abstract

A parametric study was performed to examine the seismic behaviour of moderately ductile (MD) reinforced concrete shear walls designed according to Canadian code provisions, including National Building Code of Canada (NBCC) 2010 and Canadian Standards Association (CSA) 23.3-04, when subjected to typical high-frequency eastern North America earthquakes. The numerical models were experimentally validated based on large specimens shaking table test results. The results obtained following the code response spectrum procedure were compared with the results from inelastic response history analyses to investigate the effect of higher modes on seismic force demands. The results indicate that current code provisions for MD shear walls need to be modified. A new base shear factor and shear force design envelop are proposed to evaluate the seismic shear force demand more realistically. This study also recommends that the current CSA 23.3-04 requirements for ductile shear walls for bending moments could be applied to constrain the location of inelastic flexural deformations at the base of MD shear walls.