SEISMIC PERFORMANCE OF IRREGULAR RC BUILDING FRAME

Abstract

The current study emphasises on comparing the manner in which irregular reinforced concrete (RC) building frames under earthquake loading with that of regular building configurations. Architectural and functional requirements frequently cause plan irregularities in modern construction practices, which have a significant influence on the seismic performance of structures. The main goal of this investigation is to evaluate and compare the seismic response of conventional and irregular multi-storey RC buildings by employing the analysis method known as the Response Spectrum. The study uses a G+9-storey reinforced concrete building frame. ETAABS was used to model and analyze four distinct plan configurations: a regular rectangular plan, an L-shaped plan, a T-shaped plan, and a plus (+) shaped plan. Utilising the Response Spectrum Method, analysis was conducted in compliance with relevant Indian Standard code provisions. The overall lateral stiffness of the columns and load intensity was maintained approximately the same for each building configuration to ensure a fair comparison between all structural models. Modal mass, foundation shear, storey displacement and storey drift participation proportion were all evaluated and compared for all building models' structural response parameters. The research looks into the influence of abnormality in the plan on the seismic behavior of RC framed structures. Despite having a similar overall lateral stiffness of columns, the analytical results show that irregular buildings are more susceptible to torsional effects, larger lateral displacements, and higher storey drifts than regular buildings. Due to the irregular plan geometry, the structures are significantly influenced by seismic forces. The study concludes that proper consideration of plan irregularities is essential in the evaluation and structure plan of earthquake-resistant buildings to ensure structural stability, safety, and serviceability during seismic events.