强度和变形参数的变化对土工有限元计算的影响

在土工问题的数值分析中，包含变形模量E、泊松比 两个变形参数的增量线弹性模型是一种常用的计算模型，研究和掌握E和 两个参数对土工有限元计算的影响有助于分析计算成果。首先，设想固定某一个参数而观察另一个参数变化对计算结果的影响；然后，说明用强度折减有限元法分析土坡稳定安全系数时，实际上已同时考虑了变形参数的影响。可采用剪应力? xy的等值线近似形成滑动面，滑动面单元的应力水平S等于1和特征点的位移发生突变共同作为失稳判据；最后，是用强度参数为纽带探讨这两个变形参数的互相变化关系，即E愈大，则土的强度愈大，? 愈小。

Effects of variation of strength and deformation parameters on calculation results of FEM for soil engineering

The incremental linear elastic model with modulus of deformation E and poisson’s ratio is very popular in numerical analyses of soil engineering. To research and understand the effects of E and on calculation of FEM is helpful to analysis of calculation results. Firstly, one parameter was simply assumed to keep a constant and effects of variation of another parameter were analyzed. Secondly, when the stability of slope was evaluated with FEM, the effect of E and had already been considered in strength reduction technique. The following three conditions are jointly used as a criteria to assess stability failure of slope, the contour lines of ? xy formed a sliding surface stress levels S in elements on sliding surface equaled to l and the displacement at a certain node increased suddenly. Thirdly, relationships between E and were discussed by means of strength parameters, the greater the E, the greater is the strength and the less is the of soil.