Effect of reduction in column stiffness on the seismic resilience of a building

Abstract

During the seismic event, the structure will starts yield and it cracks. This leads in the reduction of its cross-sectional area, gross moment of inertia, etc., which affects the structural stiffness. In this study, the efficiency of a building in terms of its performance level, direct economic losses, and the seismic resilience with reduction in the column stiffness was examined. A high-rise G+10 storey reinforced concrete building was considered in this study. In order to consider the cracked section to evaluate the structural safety in terms of the seismic resilience, the column section stiffness was reduced with respect to the gross moment of inertia of the section. To incorporate this reduction in the gross moment of inertia, the stiffness modifier in SAP2000 software was used. As per Indian Standard (IS: 1893-2016), the gross moment of inertia of the column can be taken as 70% for the structural analysis, hence in this study the two various cases with 70% and 100% of the gross moment of inertia of the column section was compared to find the effect of stiffness reduction in the structural functionality. Using trigonometric recovery functions, the corresponding difference in seismic resilience was evaluated. The result shows that there was a significant change in the performance level but not much dropdown in the functionality of the building and demand ductility.