Probability-based seismic safety evaluation of existing buildings

A probabilistic second-moment seismic safety measure is proposed and the seismic safety of eleven existing buildings is evaluated. These buildings are analyzed using lumped-mass models and the seismic hazard at each building site is estimated by utilizing an available probability-based seismic hazard map. Results for the distribution of the safety measure with story level suggest that significant damage may be concentrated only in a few stories in some buildings. Second-moment seismic margin indices for some buildings are relatively high, while lower seismic margins result for others, perhaps due to underestimation of the ultimate limit state resistance. The feasibility of the procedure for evaluating seismic safety of existing buildings is demonstrated.