边坡稳定分析的自适应性局部网格加密解法

Adaptive local mesh refinement method for slope stability analysis

常规的有限元强度折减法在确定边坡塑性区时,不能直观地反映出塑性区的形状和滑裂面位置,计算结果精度低。在塑性区范围内进行网格局部加密,不仅使安全系数的计算精度大幅度提高,而且可求出滑裂面的形状和位置。针对求解塑性区搜索滑裂面这一具体问题,提出塑性应变界限值网格加密准则,采用自适应性网格局部加密技术求解边坡的滑裂面和稳定安全系数。数值计算结果表明,所提出的加密准则能正确地确定滑裂面的形状和位置,计算所得稳定安全系数和理论稳定安全系数仅相差0.2%。

When the conventional strength reduction finite element method is used to determine the plastic zone of slopes,the results obtained are not so accurate,the shape of plastic zone and the position of sliding surface can not be directly visualized. Using the method of local mesh refinement around the plastic zone,one can not only improve the accuracy of the safety factor calculated greatly but also solve the shape and position of sliding surface. For the specific problems of searching the sliding surface in the plastic zone,a plastic strain limit is presented as a mesh refinement criterion. The shape and position of the sliding surface and the safety factor is determined by local mesh refinement method. A lot of numerical computations are carried out,the results have shown that the criterion used is effective for determining the shape and position of the sliding surface,and the error of the safety factor between the computed value and the accurate value is only 0.2 %.