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上限有限元法是一种常用的边坡稳定性分析方法,目前被广泛采用的仅考虑剪切破坏的Mohr-Coulomb屈服准则过高地估计了边坡的抗拉强度,因此在用其进行边坡稳定性分析时,无法得到实际工程中常遇到的位于坡体后缘的拉裂缝。针对这一问题,从空间方位离散的角度出发,对上限法中的Mohr-Coulomb屈服面逼近方式进行改造,建立基于方位离散的线性化剪切屈服准则;同时引入张拉破坏准则,保证在每一个离散方位平面上不违背张拉破坏准则,从而形成既考虑张拉破坏,又考虑剪切破坏的线性化上限原理有限元法。该方法可以准确地求出边坡的安全系数和带有拉裂缝的临界失稳速度场。算例证明方法的有效性,同时还表明不考虑拉伸破坏会过高地估计边坡的安全性。
The upper bound finite element method is a commonly used method for slope stability analysis. The Mohr-Coulomb yield criterion, which is widely used only considering shear failure, overestimates the tensile strength of the slope. Therefore, Stability analysis, can not get the actual project often encountered in the slope of the slope of the pull cracks. In order to solve this problem, the approach of Mohr-Coulomb yield surface approximation in upper bound method is modified from the perspective of spatial discretization to establish linear buckling yield criterion based on azimuth discretization. At the same time, A discrete azimuth plane does not violate the principle of tensile failure, so as to form the finite element method of linear upper bound principle that considers both the failure of tension and the failure of shear. This method can accurately calculate the safety factor of slope and the critical instability velocity field with pull crack. An example is given to show the effectiveness of the method. At the same time, it is also shown that the safety of the slope can not be overestimated irrespective of the tensile failure.