Abstract: “Indian standard codes (IS 456:2000, IS 13920: 1993) have not given particular attention for the design of setback buildings. This paper addresses the effect of irregularities in elevation on the seismic performance of reinforced concrete (RC) framed buildings with infill brick walls. The seismic parameters such as fundamental time period, inter storey drift ratio, base shear and top displacement of irregular buildings are compared with that of a regular building. The nonlinear static analysis, using user defined hinges, is used to assess the buildings with irregularities introduced at different storey levels and with different setback ratios. Nonlinear version of SAP 2000-12 is used for analysis. It is observed that the performances of these irregular buildings when designed according to the provisions of IS codes are inferior compared to that of regular building.”

Keywords: Vertical geometric irregularity, Infill, User defined hinges, Pushover analysis