Probabilistic verses deterministic method of seismic performance evaluation

Abstract

Seismic performance evaluation of existing buildings by probabilistic approach and by deterministic approach has been compared and benefits of probabilistic approach are highlighted. An old building constructed in the 80s and situated in Indian seismic zone V has been taken for the study. Different retrofitting strategies have been implemented to improve global seismic performance. Effectiveness of any retrofitting scheme is assessed by both approaches. Static pushover analysis has been implemented for deterministic approach. For stochastic approach, a probabilistic-based methodology based on Pacific Earthquake Engineering methodology has been developed. The methodology accounts well the associated uncertainties in the process of seismic evaluation. Incremental dynamic analysis-based fragility curves have been developed. It is concluded that probabilistic approach provides comparatively a broad insight into evaluation process and it accounts capacity, demand and modeling uncertainties and is able to predict the seismic performance of retrofitted buildings to futuristic earthquakes. The study also recommends the implementation of performance-based design philosophy based on probabilistic approach in Indian seismic code to match with developing countries’ current design philosophy.