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沿用确定性设计方法，该方法无法直接量化不确定性对结构安全的影响。结构可靠度（structural reliability）理论可通过定量分析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。本文以一座已建成的混凝土重力坝为研究案例，阐述了结构可靠度理论的实际应用场景。研究结果显示，已建成坝体的结构可靠度高于设计阶段的坝体可靠度。本研究将设计工况下的结构可靠度与对应安全系数进行对比分析，揭示了安全系数与可靠度之间不存在线性关联。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（failure modes）与设计参数。