Structural Demand Hazard Analysis of Jointed Gravity Dam in View of Earthquake Uncertainty

In the present paper, structural demand hazard of jointed gravity dams is studied employing probabilistic seismic demand analysis. Folsom dam is chosen as case study. It is numerically modeled along with its full reservoir utilizing the finite element method. Two analysis cases of the dam-reservoir system are considered taking into account two sources of nonlinearity: material nonlinearity of mass concrete and geometric nonlinearity of prescribed joints. A bin of 200 earthquake records are selected to capture the effects of record-to-record variability and uncertainty on the seismic response. For each analysis case, proper Engineering Demand Parameters (EDPs) are calculated in terms of various earthquake Intensity Measures (IMs). Then the optimal Probabilistic Seismic Demand Model (PSDM) is found out by assessing the resulted IM-EDP pairs based on the criteria of efficiency and sufficiency. It is concluded that the spectral values, S-a (T-1,5%) and S-a (T-2,5%) are the best choices for jointed gravity dams. Finally, the seismic fragility curves are generated, and the seismic demand hazard curves are produced by combining the optimal PSDMs with probabilistic seismic hazard analysis.