基于原生节理统计和爆破裂纹模拟的堆石料块度分布预测

 水电工程堆石料爆破级配要求高、块度预测难，以岩体原生节理统计和爆破裂纹模拟为切入点，采用现场调查、室内试验、数值仿真和工程检验等方式，开展堆石料爆破块度分布研究，尝试建立一套堆石料爆破块度预测方法。通过现场调查，绘制研究区域的天然节理分布网络图，建立基于原生节理统计的三维节理岩体模型；通过SHPB试验装置获取岩石在冲击荷载作用下的动力学参数，利用Ansys/Ls-Dyna模拟了爆破裂纹的扩展范围；综合原生节理调查信息和爆破裂纹模拟成果，建立调查区域爆后三维节理岩体模型；利用ANSYS输出模型所有岩块的线–面–体数据并编制Matlab块度计算程序，采用基于爆破岩块第5条最长边的块度预测指标，得到调查岩体的预测级配曲线。工程应用表明，综合考虑原生节理和爆破次生裂纹联合切割作用的堆石料级配预测方法基本符合工程实际，且基于爆破岩块第5条最长边指标的级配预测结果要优于等体积球直径指标的级配预测结果，其在江咀料场级配预测中的整体误差为5.5%。研究可为类似工程的堆石料爆破开采提供可借鉴的级配预测手段。

Fragmentation distribution prediction of rockfill materials based on statistical results of primary joints and simulation of blasting cracks

The strict grading requirements of rockfill materials in hydropower engineering cause the difficulty to predict the fragmentation distribution. The statistical results of primary joints and the simulation on blasting cracks were employed together with the field investigation，indoor experiment，numerical simulation and engineering test to investigate preliminarily the blasting fragmentation distribution of rockfill materials. A set of fragment-size prediction methods were established. Firstly，the distribution network of natural joints of the study area was drawn through field investigation，and a three-dimensional jointed rock mass model based on the statistical results of primary joints was established. Then，the dynamic parameters of the rocks under the impact load were obtained with SHPB test device，and the extension ranges of blasting cracks were simulated with Ansys/Ls-Dyna. A three-dimensional jointed rock mass model after blasting in the investigation area was established considering comprehensively the information of primary joints and simulation results of blasting cracks. The output data of line-area-volume from the three-dimensional jointed rock model were used for block calculation with Matlab. The fifth longest side of rock blocks was taken as a fragmentation prediction index，and finally the predicted grading curve was obtained. Engineering application shows that the gradation prediction method is in line with the engineering practice. The overall prediction error is 5.5% in Jiang Tsui quarry which is much better than that of index based on diameters of equal volume sphere.