基于耦合的欧拉-拉格朗日法的边坡稳定性分析

Research on the Stability of Slopes Based on the Coupled Eulerian-Lagrangian Method

目前边坡稳定性分析以小变形有限元研究为主,且边坡失稳判据的选取存在争议。基于大变形有限元分析技术耦合的欧拉-拉格朗日CEL法,研究土质边坡的稳定性。考察了网格尺寸、计算时长和初始地应力对模型计算结果的影响;探讨了能量突变法判据和塑性区贯通判据在CEL法中的适用性;通过与已有的数值计算结果对比,验证了CEL模型的可靠性。通过对不同判据间的对比分析,建议CEL法采用能量突变法判据;针对塑性区贯通判据,提出了临界累计塑性应变P_(c)的概念,量化了塑性区贯通判据求得的边坡稳定性系数;基于参数考察获得的113个算例的计算结果,拟合得到了用于计算土质边坡稳定性系数的经验公式,并验证了经验公式的有效性。

Now the analysis of slope stability generally adopts the small deformation finite element method,and the failure criterion is still controversial.Based on the coupled Eulerian-Lagrangian(CEL)approach,a large deformation finite element method,the stability of soil slope is investigated.The effects of mesh size,step time,initial geostatic stress on the calculating results are quantified.The applicability of energy aberration criterion and plastic failure zone criterion is discussed.By comparing the published numerical results,the effectiveness of the CEL model is verified.By comparing the results from different failure criterions,the energy aberration criterion is recommended for the CEL approach.For the plastic failure zone criterion,the critical cumulative plastic strain(P_(c))is proposed,which quantifies the determination of stability factor.With the 113 calculated results from the parametric study,an empirical formula is established to calculate the stability factor of soil slopes,whose efficiency is also verified.