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剪切带非连续变形描述及剪切带扩展过程模拟是边坡渐进破坏过程分析的关键,基于黏聚区域模型及强化有限单元法提出一种剪切带渐进扩展过程模拟的有限元分析方法。首先,将剪切带两侧相对变形分解成分别由常规应变和附加应变确定的相对位移,提出具有弱非连续变形特征的剪切带变形等效强非连续变形描述方法,并采用黏聚区域模型表征剪切带应力和附加相对位移间的软化本构关系。其次,基于强化有限单元法描述强非连续变形,并构造相应的无厚度剪切带单元。在此基础上,提出剪切带渐进扩展模拟的有限元算法。算例表明,此方法不仅能够很好地模拟剪切带的应变软化特性,而且有效地克服了常规剪切带模拟具有的网格敏感性问题。
The description of discontinuous deformation in shear zone and the simulation of shear zone expansion process are the key points in the analysis of gradual failure process of slope. Based on the cohesive zone model and fortified finite element method, a finite element method is proposed to simulate the progress of shear zone. Firstly, the relative deformations on both sides of the shear band are decomposed into the relative displacements determined by normal strain and additional strain, respectively, and the description of discontinuous deformation of shear band deformation with weak discontinuous deformation is proposed. The cohesive zone The model characterizes the softening constitutive relationship between shear stress and additional relative displacement. Secondly, the strong discontinuous deformation is described based on the enhanced finite element method, and the corresponding non-thickness shear zone elements are constructed. On this basis, a finite element algorithm of progressive simulation of shear band is proposed. The example shows that this method can not only simulate the strain softening behavior of shear band well, but also effectively overcome the grid sensitivity problem of conventional shear band simulation.