基于有限元方法的重力坝稳定可靠度计算

Reliability Computation of the Stability for Gravity Dams Based on FEM

借助于混合模拟法(HSM),通过响应面法拟合一个响应面来代替未知的真实状态曲面,再进行MonteCarlo随机抽样从而对重力坝进行稳定可靠度分析。计算中考虑上游水深、上游泥沙高度、抗剪断摩擦系数、抗剪断凝聚力、扬压力折减系数,作为随机输入变量。进一步的研究随机输入变量对抗滑可靠指标的敏感性以及材料的变异系数对抗滑可靠指标的影响,得到了一些重要的结论。指出了影响抗滑可靠度指标的最敏感因子,及提高抗滑可靠度指标的途径。算例表明HSM法计算大型非线性复杂结构的可靠度简便可行,计算结果能达到所需的精度要求。

The hybrid simulation method（HSM） is used to analyze the reliability of the gravity dam in this paper, the real state surface which is unknowned is replaced by a fitting response surface , the analytical result is calculated by the Monte Carlo random sampling. As the random input variables , the depth and sediment height in the upper raeches, the friction coefficient , shearing strength cohesion,the uplift pressure reduction factors are considered. Some conclusions are also drawn based on research on the effects of the random input variables on the sensitivity of anti-slip reliable indexes and the effect of coefficient of variation of the materials on the anti -slip reliable indexes. We point out the most sensitive factors of the anti-slip reliable indexes and the way to improve anti-slip reliable indexes. A numerical example shows that the hybrid simulation method（HSM） is a simple and feasible way to calculate the reliability of large-scale non-linear complex structures, and the calculation results also meet the requirement of precision.