基于三维非线性有限元的边坡稳定分析方法

刚体极限平衡法不能反映岩体中实际的应力分布，而基于有限元的强度折减系数法在判断收敛性方面存在一些问题。为了解决这些问题，采用多重网格法，分别建立用于有限元计算的结构网格和用于计算滑面稳定安全系数的滑面网格，可以方便地获得任意滑面或滑块的稳定安全系数，从而将非线性有限元和极限平衡分析结合起来。为了提高计算规模和计算精度，采用有限元并行计算程序TFINE.Pfem进行计算，分析了网格密度对计算结果精度的影响，并应用于锦屏高边坡的稳定分析中。与刚体极限平衡法结果的对比分析表明，由于考虑了计算过程中的非线性应力调整，该方法的计算结果比刚体极限平衡法偏大，而且更符合实际情况。

Slope stability analysis based on 3-D nonlinear finite element method

The adjustment of nonlinear stress is not taken into account in the limit equilibrium analysis of rigid body;and it is difficult to judge the convergence of the shear strength reduction method with FEM.To solve these problems,based on multi-grid method,structure grid for nonlinear FEM and sliding surface grid for calculating safety factor were established separately.So the sliding safety factor of arbitrary sliding surface or sliding blocks can be obtained.Thus limit equilibrium analysis can be integrated with nonlinear FEM.To increase calculating scale and speed,a 3-D parallel finite element code based on element-by-element method,TFINE.Pfem,is developed and used.The influence on result precision by grid were analyzed.Then it is applied to the stability analysis of Jinping high slope.The contrast analysis show that the safety factor obtained from the method proposed is larger than that of limit equilibrium analysis of rigid body because of considering of adjustment of nonlinear stress.The method porposed is accord with real conditions.