Seismic Fragility and uncertainty Analysis of Concrete Gravity Dams under Near-Fault Ground Motions

Abstract

Throughout the world there are numerous concrete gravity dam has been made in areas of very high seismicity with least attention to seismic actions. Dam safety during and after an earthquake, is the objective of the present study. The failure of a dam in a seismic excitation has dramatic consequences in terms of loss of human lives and financial losses. In the present work, an analytical fragility analysis was performed in order to characterize the seismic vulnerability of concrete gravity dams by using a numerical simulation procedure to model sources of uncertainty that could impact dam performance, with combination with non-linear dynamic response analysis. The seismic fragility of concrete gravity dams under near-fault ground motions was performed and compared to assess their performance against seismic hazards. An uncertainty analysis is also carried out to evaluate the effectiveness of the Latin Hypercube Sampling method using different combinations of performance thresholds through fragility analysis. A case study was considered, it is about the dam of Oued el Fodda on the Oued Chelif River, West Algeria. This dam was designed in the early 1930s.