基于可滑性分析的土质边坡局部稳定性研究

传统的局部安全系数计算方法通常是基于某种屈服准则,通过判断坡体内部是否发生塑性屈服来评价边坡局部稳定性。实际上,发生塑性屈服的区域通常远大于滑动面的范围,仅以是否发生塑性屈服作为局部稳定性评价指标偏于保守,为此进行坡体可滑性分析,即考虑坡体内各点具有的形成滑动面的可能性,并定义该指标为滑动因子。同时,将坡体内各点的塑性屈服程度用剪切塑性屈服系数来表示。将两者结合起来共同评价坡体的局部稳定性。研究表明,边坡局部稳定性不仅与坡体内各点沿潜在滑动面的屈服程度有关,还取决于该点形成滑动面的可能性,可表达为剪切塑性屈服系数与滑动因子的乘积。用ACADS边坡考题验证了本文方法的正确性,为边坡稳定性分析提供了思路。

Study on the Local Stability of Soil Slope based on the Slipforming Property

The traditional calculation method of local safety factor is usually based on some yield criterion, which is used to evaluate the local stability of the slope by judging whether the slope body undergo plastic yielding or not. In fact, the plastic yield area is usually much larger than the range of sliding surface, so it is conservative to take the plastic yield as the local stability evaluation index. For this reason, the whole slipforming property analysis of the slope is put forward, that is, the fixed point method is used to describe the possibility of forming the whole sliding surface with the points in the slope, and the index is defined as the whole sliding factor. In the meantime, the plastic yield level of each point in the slope is expressed by the shear plastic yield coefficient. The two factors are combined to evaluate the local stability of the slope. The results show that the local safety factor is related not only to the current stress state, but also to the possibility of forming the whole sliding surface, which can be expressed as the product of the shear plastic yield coefficient and the sliding factor. In this paper, we use the ACADs referenced slope example to verify the correctness of the calculation method, which provides a new idea for slope stability analysis.