地下空区激光三维探测及稳定性分析

为了解决地下空区对露天矿安全生产的影响,针对洛钼集团露天开采境界下覆不明空区,利用激光三维扫描系统通过地表钻孔对空区进行精确三维探测,把激光三维探测的数据导入SURPAC建立空区三维块体模型,研究了SURPAC和FLAC~(3D)的数据转换方式,并编制相应程序把空区三维块体模型导入软件FLAC~(3D)进行稳定性数值分析.计算结果显示:该空区模型内各单元内的不平衡力趋近于0;节点(6066,4775,1430)处的Z方向位移趋近于恒定值;初始平衡状态下围岩最大位移量约为0.086 m;围岩中最大拉应力为1.52 MPa,应力集中区最大压应力为12.37 MPa,均小于岩体的抗拉、抗压强度.由此表明,该空区上方地表运动停止,空区上方围岩不会发生拉裂破坏,空区目前处于稳定状态.

Laser 3D Detection and Stability Analysis of Underground Cavity

A laser three dimensional scanning system was used to identify cavities under the open-pit Luoyang Luanchuan Molybdenum Co. Ltd. mine. Safe production requires the identi-fication of cavities smaller than a certain size, which might present a danger to operations. A diagram of the cavity's plan, with upper and lower face elevations, was developed from the la-ser 3D data. Laser data were imported into the software package SURPAK to form a 3D, block element model. A program was written to transform the data from SURPAK into a form suit-able for FLAC~(3D). Numerical stability analysis was performed in FLAC~(3D). The results show that each cell of this particular cavity has approximately zero imbalance. The (6 066, 4 775, 1 430) node approached a constant Z displacement. The maximum displacement from initial equi-librium in the surrounding rock is about 0.086 m. Maximum tensile stress in the rock is 1.52 MPa and the maximum compressive stress, in the stress concentration zone, is 12.37 MPa. These are both smaller values than the actual rock-mass strength. Therefore, surface move-ment above this cavity has stopped and tensile failure will not occur in the surrounding rock: This cavity is presently in a stable state.