Assessing Seismic Vulnerability of Concrete Gravity Dams: A Comparative Analysis of Damage Indexes

Estimating the potential damage or cracking in a concrete gravity dam during an earthquake is crucial for assessing its seismic vulnerability. However, the current body of literature lacks comprehensive coverage of damage indexes specifically designed for concrete gravity dams, taking into account both epistemic and aleatory uncertainties. This study intends to fill this gap by comparing the effectiveness of several damage indexes that might be used for concrete dams while rigorously accounting for uncertainties related to material properties, the intrinsic unpredictability of earthquakes, and modeling errors. To handle these uncertainties, the Latin hypercube sampling approach is utilized to sample structural uncertainties in an efficient and practical manner. The Pine Flat Dam is used as a case study, and the incremental dynamic analysis method is utilized to assess the seismic response. Evaluation of three pairs of proposed damage indexes ( \({\mathrm{DI}}_{G}\) ${\mathrm{DI}}_G$ and \({\mathrm{DI}}_{\mathrm{FSS}}\) ${\mathrm{DI}}_{\mathrm{FSS}}$ , \({\mathrm{DI}}_{G}\) ${\mathrm{DI}}_G$ and \({\mathrm{DI}}_{d}\) ${\mathrm{DI}}_d$ , and \({\mathrm{DI}}_{d}\) ${\mathrm{DI}}_d$ and \({\mathrm{DI}}_{\mathrm{FSS}}\) ${\mathrm{DI}}_{\mathrm{FSS}}$ ) reveals varying correlation strengths, with a respective coefficient of determination (R²) of 0.8556, 0.638, and 0.5532. The analysis revealed that the damage indexes \({\mathrm{DI}}_{G}\) ${\mathrm{DI}}_G$ and \({\mathrm{DI}}_{\mathrm{FSS}}\) ${\mathrm{DI}}_{\mathrm{FSS}}$ exhibited the most significant correlation with the peak ground acceleration, with respective R² values of 0.884 and 0.879. The findings derived from this study make a valuable contribution to enhancing the strength and dependability of evaluating the earthquake risk of concrete gravity dams while considering several factors of uncertainty.