重力坝的坝与地基体系可靠度分析方法研究

Study on Analysis Method of Reliability of Gravity Dam-Foundation System

可靠度是反映重力坝结构安全稳定的重要指标之一,研究复杂地质条件下混凝土重力坝体系可靠度具有重要的工程意义。因此,在以弹塑性增量分析法识别重力坝坝与地基主要失效模式的基础上,以Drucker-Prager准则和抗剪断准则构建坝体及地基失效的功能函数,提出了多种失效模式下重力坝的坝与地基串联体系可靠度的Monte Carlo法。通过某重力坝体系可靠度分析显示,其体系可靠度较传统单一失效模式可靠度小,符合工程实际,表明这种方法能合理地分析重力坝结构的体系可靠度,对于合理评价重力坝整体安全具有重要的参考价值。

Reliability is one of the important indexes reflecting safety and stability of gravity dam structure.It is of great engineering significance to study the reliability of concrete gravity dam system under complex geological conditions.In this paper,based on identification of main failure modes of gravity dam and foundation by elastic-plastic incremental analysis method,the performance function of dam body and foundation failure is established using DP yield criterion and shear-resistant formula,and the Monte Carlo method of series system reliability of gravity dam-foundation under various failure modes is proposed.The reliability analysis of a gravity dam shows that the system reliability is smaller than that of the traditional single failure mode,which is in line with the engineering practice.It shows that the method proposed in this paper can reasonably analyze the system reliability of the gravity dam structure,and has important reference value for the accurate evaluation of the overall safety of the gravity dam.