Commercial Building with Vertical Irregularities Using Etabs Software

Abstract

Building on hilly slopes is always a challenge because the natural ground profile forces engineers to adopt unconventional building forms like step-back or step-back & set-back structures. These designs often create vertical irregularities, since the columns rest at different heights, which makes the structure more vulnerable to torsional effects and increased shear during an earthquake. To understand this behavior, the present study uses the Response Spectrum Method to analyses step-back and step-back & set-back frames. The focus is on key seismic responses such as fundamental time period, lateral displacement, inter-storey drift, and base shear in columns for buildings of different heights. The results clearly show that step-back & set-back frames perform better under earthquake loads compared to simple step-back frames, as they control displacement, reduce story drift, and distribute base shear more effectively.