边坡稳定的剪切带计算

为了解决边坡稳定分析中剪切带有限元网格的依赖性问题,采用梯度塑性理论,从本构关系中引入特征长度入手,建立计算模型。提出了一种8节点缩减积分的梯度塑性单元,并采用梯度塑性理论推导了Drucker-Prager屈服准则的软化模型的有限元格式,在ABAQUS中进行了二次开发,嵌入了本文提出的8节点单元和本构模型,并用ABAQUS软件进行了边坡剪切带的计算。计算结果表明,本文提出的方法消除了经典有限元计算的网格依赖性问题,可以得到与单元剖分无关的稳定的剪切带宽度。本文所提出的方法可适用于其他场合的剪切带计算。

Calculation of shear band for slope stability

In order to circumvent the mesh-dependence problem in calculating the shear band for slope stability by finite element methods,the gradient-dependent plasticity theory is adopted.In this paper an eight-node gradient-dependent element with reduced integral is presented to establish the model and at the same time a characteristic length is introduced into the constitutive equation.The finite element format of Drucker-Prager plasticity model with strain softening is deduced,and some numerical examples for shear band in slope stability are done in ABAQUS/Standard through the user subroutine UEL.The result shows that the method presented in this paper can eliminate the mesh-dependence problem in classical finite element methods,and steady shear band width can be achieved regardless of mesh.The method in this paper can be suited for other occasions that need calculation of shear band.