露天转地下挂帮矿开采边坡稳定性及失稳模式研究

Study on Stability and Failure Mode of the Slope Caused by Hanging Wall Ore Mining from Open-pit to Underground Mining

为研究露天转地下挂帮矿的开采工作面倾角的布置方式对工作面上覆岩体应力与边坡失稳破坏模式的影响,以海南矿业公司露天边坡挂帮矿井采为例,采用理论计算和数值模拟相结合的方法对其进行了分析。结果表明:露天边坡下开采时工作面倾角的布置对边坡稳定性影响显著;工作面倾角由30°到-30°逐渐减小的过程中,工作面上覆岩体及露天边坡台阶变形量越大,边坡内上覆岩体内剪切应力集中程度和最大主应力集中程度越来越高,边坡失稳破坏的趋势增强;边坡围岩上部压力拱成拱机制较弱,开采工作面右端位移临界区域岩体的抗剪强度对边坡整体稳定性起到关键作用;露天边坡下开采边坡岩体不同区域可能发生的失稳破坏模式主要为张拉破坏—垮落破坏—剪切滑移破坏—剪切错动破坏—挤压鼓胀破坏。

In order to study the influence of layout form of mining working face angle of hanging wall ore from open-pit to underground mining on the overlying rock mass stress and slope failure model,the theoretical calculation and numerical simulation method are used to do the above analysis. The study results show that： the influence of the layout of the mining working face angle of open-pit slope on slope stability is significant; during the decreasing of the working face angle from 30° to -30°,the bigger deformation of overlying rock mass and open-pit slope steps,the higher concentrating degree of shear stress and maximum principal stress,and the trend of slope failure is strengthened gradually; arching mechanism of the upper pressure arch of surrounding rock is weak; slope stability is influenced emphatically by shear strength of the rock mass in critical displacement region located in the right side of mining working face; the failure model may be occurred in the different regions of the rock mass of open-pit slope are tensile failure,collapses failure,shear sliding failure,shear dislocation failure and crushing ballooning failure.