Comprehensive Reliability Analysis of Seismic Stability for Concrete Gravity Dams: A Case Study of Pine Flat Dam

This research employs a sophisticated finite element model to conduct a comprehensive reliability analysis, focusing specifically on the earthquake behaviour of the Pine Flat Dam in Fresno County, California. The developed finite element model incorporates the intricate interaction among the dam, water, and foundation rock, accounting for essential factors such as compressible water, flexible foundation effects, and absorptive reservoir bottom materials. In addition, the model effectively captures the dam-water-foundation rock model's reaction during seismic events. Furthermore, the Latin hypercube sampling method is employed to address uncertainties related to material properties, modelling inaccuracies, fluctuating water levels in the reservoir, and the inherent randomness of earthquakes. Incremental dynamic analysis is then conducted to generate fragility curves, offering valuable insights into the probability of exceeding various damage states. By utilizing the observed cracking severity in the concrete gravity dam and the corresponding conditions leading to global instability, a matrix of damage states is established. Through the correlation of damage indices, this study identifies limit states in the dam's response and plots corresponding fragility curves. The derived fragility curves serve as valuable tools for risk assessment, decision-making, and the formulation of effective mitigation strategies, ensuring the seismic safety of concrete gravity dams.