Seismic Fragility Assessment of Reinforced Concrete Buildings in Delhi Using IS 1893:2016 and Monte Carlo Simulation

Rapid urbanization and inconsistent enforcement of seismic design provisions have increased the vulnerability of reinforced concrete (RC) buildings in Delhi, a Seismic Zone IV region under IS 1893:2016. This study presents a probabilistic seismic fragility assessment of RC frame buildings using a Monte Carlo simulation framework based on IS 1893:2016 provisions. Structural response was evaluated using the IS 1893:2016 design response spectrum, and damage probabilities for slight, moderate, and collapse damage states were estimated using lognormal fragility functions. The results indicated a progressive increase in damage probability with increasing spectral acceleration. Estimated peak ground acceleration values ranged from approximately 0.002 g to 0.025 g across simulated earthquake scenarios. Slight damage probabilities were consistently high across the simulated scenarios, while moderate damage probabilities ranged from approximately 0.02 to 0.95 depending on seismic intensity levels. Collapse probabilities remained relatively low under moderate seismic demand and increased under elevated spectral acceleration levels, indicating greater structural vulnerability under severe ground-motion conditions. The proposed framework demonstrates the applicability of probabilistic seismic fragility assessment for evaluating seismic risk in Indian urban regions and supports earthquake risk mitigation and resilience planning.