Performance-Based Seismic Analysis of Mid-Rise Buildings in Northeast India (Zone 5)

Abstract This paper presents a comprehensive nonlinear seismic assessment of mid-rise reinforced concrete (RC) buildings located in Northeast India's Zone 5 using Performance-Based Seismic Design (PBSD) methodology. Two building models, one regular and another with a soft-storey irregularity, were analyzed using Nonlinear Time History Analysis (NLTHA) and Incremental Dynamic Analysis (IDA). Fragility curves were developed to quantify seismic vulnerability. Results highlight the pronounced drift concentration in soft-storey structures and emphasize the necessity of PBSD integration into seismic codes for critical regions. Keywords Performance-Based Design, Seismic Zone 5, RC Buildings, Nonlinear Time History Analysis, Fragility Curves, Soft-Storey Irregularity