边坡在二次卸荷过程中的应力变化规律研究

Study on Variation Rule of the Slope Stresses during the Second Unloading Process

露天矿边坡驻留矿体开采使边坡产生了第二次卸荷作用。通过数值模拟计算,研究了驻留矿体开采边坡岩体的应力变化机理,分析了边坡稳定性情况。研究表明,驻留矿体的开采不会影响边坡的整体稳定性,但由于露天开采的第一次卸荷作用的影响,导致地下采场上覆岩层的成拱机制减弱,采场围岩中存在着较大拉应力,采场稳定性差。

The recovery of the residual ore-body under the slope of the open-pit,easily results in the second unloading of the slope.Through the numerical analysis,the change mechanism of the slope stress in the mining of the residual ore-body is investigated and the slope stability is analyzed.The result shows that the mining do not affect the slope stability.But the arching mechanism in the roof strata is weakened by the first unloading of the open-pit mining,large tensile stress exists in the surrounding rock of the stope,so the stability of the stope is weakened.