土体抗拉强度对均质边坡稳定性的影响

目前对均质边坡稳定性受岩土体抗拉强度影响程度的看法不一，尤其是对不同坡度的边坡受抗拉强度的影响甚至有相反意见。基于有限差分程序FLAC^3D提供的考虑张拉-剪切复合破坏的Mohr-Coulomb准则，采用强度折减法对多个典型均质边坡进行一系列数值计算，研究土体抗拉强度对不同坡度边坡稳定性的影响。结果表明：边坡越陡，土体抗拉强度对安全系数的影响越大；抗拉强度取值对直立边坡的稳定安全系数及变形破坏特征影响显著，对45°及以下边坡的影响相对较小。总体来说，对于坡角超过60°的陡坡，土体抗拉强度不同引起的边坡安全系数变化幅度可达10%以上，应在边坡稳定分析中特别注意，避免因土体抗拉强度取值过大或过小而导致计算结果偏于危险或过于保守。

Influence of Soil Tensile Strength on Stability of Homogeneous Slope

There are different opinions on the influence of tensile strength on the stability of homogeneous slopes, especially for slopes with different inclinations. Based on the composite tension-shear Mohr-Coulomb criterion provided by the finite difference program FLAC^3D, a series of numerical calculations were carried out for several typical homogeneous slopes by using the strength reduction method. The influence of soil tensile strength on the stability of slopes with different inclinations was studied. The results show that the steeper the slope is, the greater the influence of soil tensile strength on the safety factor of the slope. The value of soil tensile strength has great influence on the safety factor, deformation, and failure characteristics of vertical slopes. The influence on 45° inclined and gentler slopes is relatively small; while for the steep slope inclined over 60°, the variation range of the slope safety factor caused by different soil tensile strength can reach more than 10%. Therefore, special attention should be paid to the soil tensile strength in the stability analysis of steep slopes, so as to avoid the calculation results being too dangerous or too conservative because the selected value of soil tensile strength is too large or too small.