堤防渗流场参数敏感性三维随机有限元分析

采用随机有限元分析方法,研究了长江荆南干堤的三维各向异性非均质稳定随机渗流场中的随机参数和随机边界条件对渗流场模拟结果的影响,并进行敏感性分析.通过统计模拟和假设检验,建立并验证了该干堤渗流场内服从独立正态分布的渗透系数张量;讨论了堤防土层的地质结构特性、堤防渗透变形及破坏的特征、堤防渗透参数的敏感性;研究了上、下游水头随机边界条件、垂直防渗边界条件以及减压(导渗)沟随机特性的敏感性.实现了对渗流场的全面随机模拟和分析,得到的结论通过统计检验,并根据实测工程数据对照证明是可靠的.

Sensitivity analysis on parameters of seepage field in dikes based on the three dimensional stochastic FEM

The sensitivity analysis of the influences of random parameters and boundary conditions on 3 D stochastic anisotropic heterogeneous steady seepage flow fields in dikes was investigated by using stochastic FEM. The statistic simulation and verification of randomization revealed that the permeability coefficient tensor obeyed the law of Gaussian distribution. The sensitivity of the influences of geological fabrication of dike stratum, dike seepage deformation characteristics, dike medium permeability were studied and the influences of the random upstream and downstream water head, vertical seepage resistance measures and ditches for reducing seepage pressure were discussed. The validity of the analysis result was verified by engineering practice.