Seismic Vulnerability Assessment of Conventional RC and Monolithic Structures Using ETABS and Demand-Capacity Ratio Analysis

The seismic vulnerability of the reinforced concrete (RC) buildings remains major concern in the earthquake prone regions where the structural discontinuities as well as insufficient stiffness result in the severe damage. In context, the present study evaluates as well as compares the seismic performance of the conventional RC framed structures and monolithic systems using the ETABS platform, based on the response spectrum analysis in accordance with IS 1893:2016. The assessment focuses on key response parameters which include the base shear, storey displacement, storey drift, as well as the storey shear, along with the structural safety evaluation using Demand Capacity Ratio (DCR). The results indicate that monolithic structural system exhibits increase in the base shear of approximately 10–11 % because the stiffness remains higher, while the reduction in storey displacement of about 15–18 % is achieved across the seismic Zones II to V. The storey drift values for the monolithic system remain within permissible limits, whereas the conventional framed structure exceeds allowable limits in the higher seismic zones. Furthermore, DCR values greater than unity are observed in the several members of the conventional frame, which indicates the potential structural vulnerability, while the monolithic system maintains values within the safe limits. The novelty of the study lies in the integrated comparative analysis which incorporates the DCR based safety evaluation across the multiple seismic zones, which provides comprehensive understanding of the structural behaviour as well as demonstrates the effectiveness of the monolithic construction in enhancing the seismic resilience.