Use of Incremental Dynamic Analyses for Nuclear Fragility Assessment

A fragility curve expresses the conditional probability of failure of a structure for a given input motion parameter, such as the peak ground acceleration or spectral acceleration. In nuclear engineering practice, fragility curve is evaluated by using margin factors. This approach represents a very convenient method but it adopts strong simplifying hypotheses. In the last years, fragility curves have also become very popular for assessing the seismic vulnerability of civil structures and one of the best current practices is the use of non-linear dynamic analyses. In this context, incremental dynamic analyses have been used in conjunction with a pushover analysis to assess a building used as a storage facility for vehicles and equipment, within a nuclear power plant in UK. The main functional requirement of the building is to provide a facility to store and maintain back-up and emergency response equipment that may be required by emergency responders for the nuclear power station.