Seismic Assessment of Clayey-Core Earth Fill Dams Using Performance-Based Fragility Curves and Finite Difference Analyses

To reduce uncertainties regarding seismic loading scenarios and numerical modeling limitations, the performance-based fragility curves of two California clayey-core earth fill dams (the Anderson and Lexington dams) were developed for the first time using the results of over 170 finite difference seismic analyses. Permanent deformations were considered as the damage index (DI), and fragility curves were generated based on three intensity measures, including the peak ground acceleration (PGA), specific energy density (SED), and Arias intensity (I_a). The results illustrated that the intensity measure significantly affected damage possibilities, and it was essential to simultaneously use all fragility curves based on various intensity measures for proper assessment of seismic vulnerability. Furthermore, evaluation of SED- and I_a-based fragility curves demonstrated that separation of near- and far-field records was critical to generate correct fragility curves when using energy-based parameters as intensity measures. Besides, SED-based fragility curves had the most conservative results, followed by PGA- and I_a-based ones.