极限平衡分析中加固力对岩质边坡稳定性的影响

Effect of strengthening force on rock slope stability in limit equilibrium analysis

分别对考虑加固力作用边坡稳定性分析的Morgenstern-Price法、严格Janbu法和Sarma法,推导了安全系数的计算过程。在不考虑力矩平衡的情况下,分析加固力对条块抗滑力和安全系数的影响,然后在考虑力矩平衡的情况下,分析Morgenstern-Price法中加固力对条块安全系数的影响。结果表明,边坡的安全系数随着加固力和内摩擦角的增大而增大。当滑裂面与水平面的夹角小于某一角度时,条块的安全系数随着加固力与水平面的夹角的增大首先呈现先增大的趋势,在达到极大值后呈现减小的趋势。当滑裂面与水平面的夹角大于某一角度时,条块的安全系数随着加固力与水平面的夹角的增大而减小。最后通过一个边坡稳定性分析的简单算例,说明本文理论分析是正确合理。且在同等条件下,加固力作用在边坡下部比作用在上部的效果要好。

This paper presents the derivations of safety factors computations with three methods for slope stability analysis methods, i.e., the Morgenstern-Price method which considers the effect of the strengthening force, the rigorous Janbu method and the Sarma method. The effect of the strengthening force on the anti-slide force and the safety factor of slice is analyzed by neglecting the moment equilibrium at first. The similar analysis is then carried out by using Morgenstem-Price method with consideration of the moment equilibrium. The result shows that, the safety factor of the slope increases with the increase of the strengthening force and the internal friction angle. When the angle a between the slide plane and the horizontal plane is smaller than a specific value, with the increase of the angle β between the strengthening force and the horizontal plane, the safety factor of slice increases at first and after reaching the maximum, it decreases. When the angle a is larger than a specific value, the safety factor of slice decreases with the increase of β. An analysis of the case example indicates the rationality of the cognition presented. Under similar conditions, it is more effective when the strengthening force is acting at the lower part of the slope than that acting at the upper part.