分区开采露天矿凹形端帮力学及几何特性研究

Research on mechanical and geometric characteristics of concave end- slope in open-pit mine with mining by areas

为了研究分区开采的露天矿凹形端帮几何、力学特性,与圆形深凹露天矿进行对比,明确了端帮岩环共轴特性,并推导出了岩环拱高与平面曲率半径的函数关系,求导得到了平面曲率半径的最小值,同时还推导出上部境界平面曲率半径与端帮高度之比的表达式,并得出了该比值的最小值为端帮边坡角的余切值.通过力学建模分析,推导出了考虑侧面压力时的凹形边坡稳定系数计算公式,并明确了影响凹形端帮稳定性的关键因素有上部平面曲率半径与坡高之比和凹形端帮暴露面积.利用数值模拟对凹形端帮进行稳定性分析,验证了力学模型的准确性,揭示了各影响因素与稳定系数的耦合规律.

In order to study the geometric and mechanical features of concave end-slope in open pit mine with mining by areas,by contrast with deep furrow pit,the coaxial features of rock ring at endslope was cleared,and the functional relationship between arch rise and the curvature radius of rock ring was deduced.Through derivation,the minimum radius of curvature was obtained.Besides,the ratio expression of the curvature radius of upper boundary and the height of end slope was deduced, whose minimum value was the cotangent of the end slope angle.According to the mechanics modeling analysis,the calculation formula for concave slope stability factor with lateral pressure was deduced, and it was also identified that,the key factors that affecting the stability of concave slope was the ratio between the upper boundary curvature radius and the slope height,as well as the exposed area of concave end-slope.When numerical simulation was used for stability analysis of concave end slope,the accuracy of the mechanical model was verified,and coefficient rules for influence factors and stability were achieved.