Comparative Seismic Analysis of Symmetric and Asymmetric RCC Buildings Using ETABS Under Equivalent Static Method

This study presents a comparative seismic analysis of symmetric and asymmetric RC buildings using the Equivalent Static Method as specified in IS 1893:2016. Two G+5 Storey RC buildings, one with a regular rectangular plan and the other with an L-shaped asymmetric configuration, were modeled and analyzed in ETABS software. Identical material properties, loadings, and structural dimensions were maintained for both models to isolate the impact of plan geometry. Key seismic response parameters that were studied included base shear, Storey shear, Storey drift, and Storey displacement. These parameters were evaluated under seismic loads applied in both X and Y directions. Results showed that the asymmetric structure experienced moderately higher responses, with an 8.13% increase in base shear and up to a 10.02% increase in top Storey displacement compared to the symmetric counterpart. Despite these increases, all values remained within the permissible limits outlined in IS 1893:2016. The findings emphasize the influence of plan irregularity on lateral seismic response and support the need for more advanced dynamic analyses in future studies.