自然崩落法矿岩质量三维数字化评价方法

针对传统以岩体构造调查或岩石力学试验处的局部RMR 值来近似表征整个区域矿岩质量存在的片面性、经验性等缺点, 提出了一种矿岩质量三维数字化评价方法。该方法以钻孔和岩体原位调查数据为基础, 选取岩石单轴抗压强度、岩石质量指标、节理间距、节理条件和地下水条件作为矿岩质量评价指标, 研究各指标的空间变异特性, 基于区域化变量最优估值理论及RMR评价体系, 将各指标插值到离散后的矿岩空间, 建立起评价区域矿岩质量的三维数字化模型。最后以该模型为基础, 应用Laubscher崩落图对矿区初始和持续崩落水力半径进行预测。该方法在普朗铜矿的应用实践表明: 普朗铜矿平均RMR值为42.27, 矿岩可崩性为较好~好, 持续崩落水力半径为21.6~22.6 m, 与生产实际相符, 为普朗铜矿采用自然崩落法进行大规模开采提供了支撑和依据。

Evaluation of Rock Mass Quality in Block Caving with 3D Digitalization Method

Local RMR obtained from rock mechanics investigation or experiment is generally used to approximately represent rock mass quality of the entire mining area, which is usually one-sided and empirical. An evaluation with 3D digitalization method was presented, in which rock uniaxial compressive strength, RQD, joint spacing, joint status and groundwater status are taken as parameters based on drilling and in-situ survey data for evaluating rock mass quality and the spatial variability of each parameter is analyzed. With the theory of optimized valuation of regionalized variables and the evaluation system of RMR, an evaluation model with 3D digitalization is established to predict the hydraulic radius for initial and sustained caving in underground mining based on the Laubscher caving chart. The practical application of this method in Pulang Copper Mine gave the following results: the average RMR of Pulang Copper Mine is 42.27, orebody shows some sort of good cavability, and the hydraulic radius required for sustained caving is in the range of 216~22.6 m, which is in a good agreement with practical production and provides support or basis for the decision of block caving method in large-scale exploitation of Pulang Copper Mine.