边坡开挖分级对有限元强度折减法计算结果的影响

Influence of Soil Gradation in Slope Cutting on Strength Reduction FEM Result

在边坡开挖稳定性分析计算中,针对开挖分级选取的比较少,而每级开挖深度比较大,经常造成计算结果有一定误差的情况,选用了ANSYS软件,利用有限元强度折减系数法,开展了有限元数值计算。根据具有代表性的实例计算结果可以知,在有限元强度折减法分析边坡开挖时,不同的分级对稳定性安全系数的影响相差可达5%以上。分级越多,稳定性安全系数越大。而塑性应变区域的大小也随着分级的增大有稍微变大的趋势。因此在模拟边坡开挖的计算时,应该有足够的分级,以保证计算结果达到稳定的收敛状态。

Aiming at less soil gradation and excavation depth degree of each stage in stability analysis of slope cutting and calculation result may have error at the depth of each gradation, finite element calculation based on ANSYS software and the strength reduction finite element method are presented. The calculated result of typical example are used to evaluate the method. The result shows that, the effect of different gradation on stability safety coefficient may be 5% or more when strength reduction finite element analysis is done; the more the gradations are, the larger the stability safety factor is. The size of the plastic deformation region will be extended with the increase of gradations. So it should have enough gradations when finite element calculation is adopted in order to make the computed results have steady convergence.