基于极限平衡法与强度折减法的某高寒高海拔矿山边坡稳定性分析

Slope stability of an alpine and high altitude mine based on limit equilibrium method and strength reduction method

为验证西部高寒高海拔地区某露天矿山设计边坡稳定性是否满足现行规范要求,并分析露天开采导致的位移变化规律,本文参考矿区终了境界平面图选取具有代表性的典型剖面,结合矿区实际情况、工程地质条件、室内物理力学试验,利用H-B准则等,综合确定矿区边坡的岩土体物理力学参数;采用极限平衡法中的不平衡推力法和M-P法及有限差分强度折减法,以安全系数为指标,验证了设计边坡的稳定性。通过极限平衡与强度折减计算结果的对比,验证了强度折减法计算潜在滑动面形态及安全系数的可靠性。在此基础上,分析强度折减前,在岩体开挖、施加爆破及地震荷载下矿山边坡的位移显现规律。研究结果可为露天矿山设计中的边坡稳定性定量分析提供参考。

In order to verify whether the stability of the designed slope of an open-pit mine in the western alpine and high-altitude area meets the requirements of the current specification,and to analyze the change rule of the displacement caused by open-pit mining,a representative typical profile is selected with reference to the end-ofarea plan of the mine,and the geotechnical parameters of the rock and soil body of the slope of the mine are comprehensively determined by combining with the actual situation of the mine area,engineering geological condi⁃tions,and indoor physical-mechanical tests using the H-B criterion and so on.The stability of the designed slopes was verified by using the unbalanced thrust method and M-P method in the limit equilibrium method and the finitedifference strength discount method,with the safety coefficient as the index.The reliability of the strength discount method in calculating the potential sliding surface morphology and the safety coefficient is verified through the comparison of the calculation results of limit equilibrium and strength discount.On this basis,the displacement pattern of mine slopes under rock excavation,blasting and seismic loads before strength reduction is analyzed.The results of the study can provide a reference for quantitative analysis of slope stability in the design of open pit mines.