地下开采扰动对露天排土场边坡变形破坏的影响

Deformation and failure regulations of open-pit mine dump caused by underground mining

为了研究地下开采对上覆露天矿排土场边坡变形破坏的影响规律,以酸刺沟煤矿及哈尔乌素露天矿排土场为研究对象,分析了地表沉陷规律及其诱发排土场变形破坏的机制,采用概率积分法对地表沉陷量进行了预测,并借助FLAC^(3D)软件分析排土场边坡变形及地表塌陷,同时分析了酸刺沟煤矿工作面回采结束后,哈尔乌素露天矿排土场的位移变化。结果表明:概率积分法预测最大沉陷量为21 m左右,模拟计算最大沉陷量为22 m左右;两者的地表最大沉陷量均随着开采阶段的进行先增大后逐渐趋于稳定,符合地表沉陷形成移动盆地的规律;数值模拟结果和实际塌陷区位置一致;排土场边坡水平位移量与工作面推进长度呈正相关;工作面走向上,采空区两侧水平位移最大,呈现出向采空区中部滑移的特征,且总体表现为左侧边坡水平位移大于右侧边坡。

To study the influence of underground mining on the deformation and failure of the overlying open-pit mine dump slope,the Suancigou Coal Mine and the Harwusu Open-pit Mine dump were taken as the research objects,and the regulations of surface subsidence and the induced failure of open-pit dump were analyzed.The mechanism of deformation and failure was predicted by the probability integral method,and the deformation and surface subsidence of the dump were analyzed with FLAC^(3D)software.And the displacement changes of the open-pit dump after the mining of underground working face were analyzed.The maximum subsidence predicted by the probability integral method is about 21 m,and that calculated by FLAC^(3D)simulation is about 22 m.The maximum surface subsidence of both methods increases firstly and then gradually stabilizes with the progress of the underground mining,and which conforms to the surface subsidence regulation of moving basins.The numerical simulation results are consistent with the actual location of the subsidence area.The horizontal displacement of the dump slope is positively correlated with the advance length of the working face.Along the working face strike,the horizontal displacement maximizes on both sides of the goaf,showing the characteristics of sliding to the middle of the goaf,and generally,the horizontal displacement of the left slope is greater than that of the right slope.