考虑材料非均质性的胶凝砂砾石坝随机有限元分析

Stochastic finite element analysis of Hardfill dam with considering the material heterogeneity influence

在对胶凝砂砾石材料力学性能指标搜集、整理、统计和分析的基础上,建立弹性模量随机场模型,运用Monte-Carlo随机有限元法研究材料非均质性对大坝静力工作性态的影响。计算结果表明:特征点位移离散性较小,变幅最大不超过13.7%;应力离散性较大,变幅最小不低于18.8%,最大可达110.5%;坝体应力和位移取统计均值后分布规律与材料均质确定性模型下基本一致;坝体应力和位移离散性在上下游面、顶部、坝踵和坝趾处较大,变异系数最大达到0.21,而内部则较小,变异系数不超过0.08;在均值上下三倍标准差区间内,位移极值点处变化率不超过5%,而应力极值点处变化率不小于18.4%,最大达到375%。

Based on the collection, sortation, statistics and analysis of Hardfill material mechanics performance indexes, Monte-Carlo stochastic finite element method is adopted to study the static working behavior of Hardfill dam with considering the heterogeneity of material mechanical properties influence and the random field of the modulus of elasticity has been built. The results show that the displacement response is small and the amplitude of changes is not more than 13.7 %, while the stress response is relatively greater and the amplitude of changes is not less than 18.8 % and maximum reaches 110.5 %. The mean responses of stress and deformation of dam are consistent with the homogeneous model. The variability of stress and deformation of the upstream and downstream, the top, the heel, and the toe of the dam is strong and the maximum variation coefficient reaches 0.21, while the internal part of the dam is not very prominent and the coefficient of variation is not more than 0.08. After the superposition with three times standard deviation, the rate of the displacement of the extreme points is not more than 5 %, while the rate of the stress of the extreme points is not less than 18.4% and maximum reaches 375%.