Seismic fragility for high CFRDs based on deformation and damage index through incremental dynamic analysis

In this paper, a seismic fragility analysis method based on incremental dynamic analysis (IDA) is extended to evaluate the seismic performance of high concrete face rockfill dams (CFRDs). Permanent deformation and face-slab damage index using a modified generalized plasticity model for rockfills and a plastic-damage model for face-slabs are considered to be dam damage measures (DMs) after defining a new face-slab damage index. The verification to damage index through the Zipingpu CFRD and previous research indicates that the grading standards are reasonable. Fragility curves and the probabilities are determined for each DM under different earthquake intensities. The results of fragility analysis demonstrate that this method can provide a strong scientific basis for predicting the earthquake destruction and loss of high CFRDs. •A fragility analysis method is extended to evaluate the seismic performance of CFRDs.•A new damage index is proposed for seismic damage assessment of face-slabs.•Synthetical indexes of dam damage measures are suggested.•Seismic performance of the structure and its various limit states are recognized.•Fragility curves and probabilities are determined for each earthquake intensities.