The unpredictable feature of earthquake is one of the major reasons for building damages and casu- alties occurring in earthquake events. Despite earthquake-induced structural damages to buildings, ground shaking can also impose critical effects on nonstructural components and systems in buildings. This study aimed to develop a probability-based approach for evaluating seismic damages to emer- gency power supply systems (EPSSs) in Taiwanese hospitals. For this purpose, four case hospitals that were somewhat damaged in the Chi-Chi earthquake (September 21, 1999) were investigated, and the component scoring system developed by the Multidisciplinary Center for Earthquake Engineering Research in the United States was referenced as the basis for developing seismic fragility curves for the components in the EPSSs of the case hospitals. Additionally, the logic tree method was employed to evaluate the failure probability of the EPSSs. The results exhibited acceptable consistency with the recorded damage status of the investigated systems, thereby verifying the feasibility of the proposed approach.
emergency power system, failure probability, logic tree, seismic fragility
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