三维边坡稳定性边界效应分析

Three-dimensional boundary effect of slope stability

利用FLAC3D程序建立边坡三维数值计算模型,分析不同边界条件如全约束边界、半约束边界以及自由边界对边坡安全系数及滑动面的影响。研究结果表明:在全约束边界条件下,边坡的安全系数最高;在半约束边界条件下,边坡的安全系数次之;在平面应变模式下,边坡的安全系数最小,且与自由边界条件下得到的安全系数非常接近;当对称均质边坡的宽高比满足一定条件时,全约束边界与半约束边界等效,由此得到的安全系数及滑动面形态也相同。

The three-dimensional numerical analysis model was founded by FLAC3D program for slope, and different boundary conditions such as rough-rough boundary, rough-smooth boundary and smooth-smooth boundary were built in the model. The effect of boundary conditions on the factor of safety and slip surface of slope was studied. The results show that the safety factor of slope is the largest under the rough-rough boundary, the second under the rough-smooth boundary, and the smallest under the plane strain mode, which is closer to that of smooth-smooth boundary model. If the symmetrical homogeneous slope meets some conditions for the width-height ratio, the results from the rough-rough boundary and rough-smooth boundary are the same, which leads to the same safety factor and slip surface mode.