Reliability analysis of built concrete dam

Abstract The conventional design of concrete gravity dams still follows the deterministic method, which does not directly quantify the effect of uncertainties on the safety of the structure. The theory of structural reliability allows the quantification of safety of these structures, from the quantification of the inherent uncertainties in resistance and loading parameters. This article illustrates application of structural reliability theory to the case study analysis of a built concrete gravity dam. Results show that reliability of the built structure is greater than that of the designed structure. The study compares reliability for design conditions, with the corresponding safety coefficients, illustrating a lack of linearity between safety coefficients and reliability. Furthermore, the study shows which are the failure modes and the design parameters with greater influence on dam safety.摘要 混凝土重力坝的传统设计仍采用确定性设计方法，该方法无法直接量化不确定性对结构安全的影响。结构可靠性（structural reliability）理论能够通过量化抗力与荷载参数中固有的不确定性，实现对这类结构安全性能的量化评估。本文将结构可靠性理论应用于某已建混凝土重力坝的案例分析。研究结果表明，已建结构的可靠性高于设计阶段的结构可靠性。本研究对比了设计工况下的可靠性与对应的安全系数，揭示出安全系数与可靠性之间并不存在线性关联。此外，本研究还明确了对坝体安全影响更为显著的失效模式与设计参数。