考虑滑体中锚拉力扩散效应的锚固边坡稳定性分析方法

Stability analysis method for anchored slopes considering stress dispersion effect in sliding mass due to anchor tensile forces

为充分考虑锚拉力在滑体中的应力扩散效应以更合理地分析锚固边坡稳定性,将作用在坡面框架上的锚拉力转化为沿坡面法向与切向的局部条形荷载,基于弹性力学Boussinesq解和Cerruti解,得到在滑面处各点的附加法向与切向作用力,将其引入边坡稳定性分析的极限平衡条分法中,给出了基于Morgenstern-Price法的相关计算公式。实例分析表明,锚拉力在滑面处产生的附加应力并非都起抗滑作用,还存在局部促滑作用,与传统的将锚拉力视为集中力的锚固边坡稳定性计算方法相比,该方法计算的稳定系数偏小,且与数值模拟分析结果更为接近。

In order to reasonably analyze the stability of anchored slopes with consideration of stress dispersion effect in the sliding mass due to anchor tensile forces, the anchor forces on the frameworks on the slope face are transformed into the locally normal and tangential strip loading, and the corresponding dispersed normal and shear stress on the slip surface is obtained using the Boussinesq's and Cerruti's solution of elastic mechanics. On this basis, the additional stress results are introduced into the limit equilibrium slice method for slope stability analysis, and the related formulas based on the Morgenstern-Price method is derived. The analysis results of a practical slope reinforced with prestressed anchor cable framework show that the additional stress on the slip surface does not fully provide resistance for the sliding mass, but a few of them are driving the sliding mass. Compared with that of the traditional analysis method for anchored slope stability in which the anchor tensile forces on the sliding mass are assumed simply as a series of single forces on the slip surface, the factor of safety obtained using the proposed method is smaller, and it is more consistent with that computed by the numerical simulation method.