地下矿体采动下的露天采场边坡稳定性研究

Research on stability of open-mining slope under underground mining

对于进入中晚期的露天金属矿,为了延长矿山的寿命或露天转地采稳产过渡,通常选择露天与地下联合开采,那么矿体采动下的边坡稳定性问题则尤为突出。在边坡几何形态、上部荷载和材料性质等不变的情况下,极限平衡获得的边坡安全系数为定值,因此,不能用来反映地下矿体采动对边坡稳定性影响。为了克服常规极限平衡方法的上述缺陷,采用基于边坡应力场的矢量和法求解滑动面的安全系数,结合蚁群算法与遗传算法联合搜索边坡临界滑动面,以确定矿体开采前后边坡的安全系数和临界滑动面。最后,给出一个假定算例和两个工程算例说明上述安全系数求解和临界滑面搜索方法的有效性,并揭示了地下矿体开采对露天采场边坡的稳定性的影响。

Generally,for some advanced open metal mines,the combined mining of open-pit and underground is adopted to extend the life of open pit mine or tide over interim of open-pit to underground,which makes the issues of the slope stability under underground mining highlighted.The slope factor of stability（FOS） solved by limit equilibrium method（LEM） is a constant value with the same geometric shape,upper load and material properties etc.of the slope,so it can not reflect the influence of underground mining on slope stability.The vector sum method which based on stress field can overcome the above shortcoming is used to solve the FOS of slip face;meanwhile,the searching of critical slip surface before and after mining is done by combined method of genetic algorithm and ant colony algorithm.Finally,an assumed example and two engineering cases are given to show the methods＇ effectiveness of solving the FOS and searching the critical slip surface,as well as to indicate the variation of the open-mining slope under underground mining.