Determination of limit-states for near-fault seismic fragility assessment of concrete gravity dams

Fragility curve, based on the performance-based earthquake engineering (PBEE), is a fundamental tool in assessing the probabilistic seismic performance of concrete gravity dams. Determination of the dam limit-states (LSs) is necessary for estimation of fragility curve. In this research, four LSs in seismic performance of massive structure have been utilized for Pine Flat dam. To address this, the Incremental Dynamic Analysis (IDA) method has been applied to the integrated dam-reservoir finite-element model. Evaluation of seismic behavior, demand and capacity of the tallest monolith has been investigated by implementing IDA. A new comprehensive method in terms of IDA and statistical analysis has been used for determination of each defined LS based on the certain value of the engineering demand parameter (EDP). To assess probabilistic performance of the dam, the exceeding probability of the LSs curves has been developed at various intensity measures based on the tree EDPs. It was found that the defined LSs have the capability indeed to be used in probabilistic framework.