复杂空间形态边坡的稳定性分析

为合理评价复杂空间形态边坡的稳定性，基于边坡的三维点安全系数，利用三维数值模拟，提出了边坡稳定性的三步点安全系数计算方法.首先，采用强度折减法降低边坡体的抗剪强度指标，使边坡处于临界状态或者大变形状态，计算边坡临界状态的位移场；其次，设置实际的边坡岩土体物理力学参数，计算当前状态应力场；最后，综合临界状态位移场和当前状态应力场，计算边坡的点安全系数.将此方法应用于贵州贞丰煤电厂运煤道路高边坡工程，计算结果表明:未加固边坡的整体安全系数虽大于设计值1.35，但坡脚局部稳定性系数小于设计值；按照点安全系数分布规律对该高边坡的下部两级边坡采用锚杆加固，确定坡脚锚杆加固的范围为下部两级边坡，锚杆加固深度为坡面以下8 m，锚杆间距为2.0 m，锚杆直径为25 mm，锚杆加固后，边坡的局部稳定性得到显著改善，坡体点安全系数均大于1.35. 

Stability Analysis of Slope with Complex Spacial Shape

Based on the three-dimensional point safety factor, a three-step point safety factor approach is proposed using three-dimensional numerical analysis to evaluate the stability of slope with complex spacial shape. First, the displacement field of slope in critical state is calculated with the reduced shear strength parameters of slope mass to obtain the critical state or large deformation state of slope using the strength reduction method. Second, the stress field of slope in current state is calculated by setting actual physical and mechanical parameters of slope mass. Finally, point safety factors of slope are obtained according to results of the displacement field in critical state and the stress field in current state. The proposed method is applied in the high slope project along the transportation road at Zhenfeng Coal-Fired Power Plant, Guizhou Province. It is shown that, the global safety factor of the unreinforced high slope is greater than the design value of 1.35, but the local safety factor at the toe is less than the design safety factor. Also, the local stability of the slope is markedly improved and its point safety factors are greater than 1.35 after the lower two levels of the high slope are reinforced by 8 m long and 25 mm in diameter anchors with a space of 2.0 m according to the distribution characteristics of point safety factors.