Elastic-displacement-based multi-modal pushover analysis in high-rise core wall buildings

Abstract

Higher mode effects play a major role in the seismic demands of high-rise buildings. Several recent studies have shown that seismic design demands such as design shear and bending moment in high-rise buildings cannot be predicted by the conventional code-based response spectrum analysis procedure. These can be determined by the more rigorous and accurate non-linear response history analysis procedure, but this procedure is computationally very extensive and time consuming. Yet a non-linear static pushover analysis cannot account for higher mode effects. Therefore, the applicability of a multi-modal pushover analysis (MMPA) procedure using elastic target displacement to cases of 20- 30- and 40-storey high-rise reinforced concrete core wall buildings is investigated in this study. The results obtained by the elastic displacement MMPA (EDMMPA) procedure are compared with those obtained from non-linear analysis. The comparison shows that EDMMPA can satisfactorily estimate the design shear force, bending moment and deformation demands with a variation of 10–20%. Thus, this computationally less demanding analysis can serve as a base line for preliminary design of high-rise reinforced concrete core wall buildings.