露天矿顺倾软岩边坡稳定性三维效应及其应用

Three dimensional effects of dip bedded soft rock slope stability in surface mines

为揭示并充分利用露天矿顺倾软岩边坡稳定性的三维效应,以白音华二号露天煤矿横采南端帮为工程背景,应用FLAC3D对不同空间形态条件下的边坡稳定性进行了数值模拟研究,分析了边坡破坏模式、稳定性、滑坡规模随横采工作帮与内排土场间追踪距离及开挖坡角的变化规律。结果表明,随着追踪距离和开挖坡角的增大,三维滑体的底界面首先由浅部弱层过渡为台阶状,最终过渡为深部弱层;边坡的稳定系数随着追踪距离的增大呈负指数规律减小,随着开挖坡角的增大近线性减小;滑体走向长度随追踪距离的增大近线性增大,倾向宽度随开挖坡角的增大而减小。绘制了白音华二号露天煤矿南端帮边坡开挖坡角与允许追踪距离间的关系曲线,据此提出了边坡稳定性控制开采方案,经现场实施,效果显著。

In order to reveal and make full use of the three dimensional effects of dip bedded soft rock slope stability in surface mines, the slope stability based on the background of the southern slope cross exploitation in Baiyinhua 2nd surface mine which was under different spatial forms was studied by numerical simulation with FLAC3D, then analyzes the change rules of the failure mode, the inner dump and the excavation angle , slope stability and sliding scale for different tracking distance between the working wall. It is shown that the bottom interface of the 3d sliding mass shift from the shallow weak layer to stepped surface firstly with the increase of the tracking distance and excavation slope angle, and then the deep weak layer finally ; the slope stability factor decreases with increasing tracking distance following the law of negative exponent ; it decreases nearly linearly while the excavation angle increase; the slide masses＇ strike length increases nearly linearly with the increase of the tracking distance; the dip direction width of the slide masses decreases with the increase of excavation angle. We propose the slope stability control program of mining based on the relationship between the excavation angle and the tolerant tracking distance, the result extinguished.