基于块体形状分类的爆堆块度三维几何参数估算

Estimation of 3D Geometric Parameters of Blasting Fragmentation based on Block Shape Classification

爆堆图像分析法是统计爆破后矿岩块度分布的主要方法,针对图像分割后得到的岩块二维图形,研究了通过岩块二维投影几何参数估算岩块体积的方法。统计分析岩体中节理面倾向、倾角和间距的概率分布,通过Monte Carlo随机模拟三维节理面网络,建立节理面切割的矿岩原始块度三维模型,利用3组相互垂直的平面切割块度三维模型获取块体二维轮廓。对于不同的二维形状参数φ值区间,分析三维形状参数ε和κ的变化规律并建立其与φ的关系式。利用块体形状分类方法将块度三维模型分成6个块体集合,根据形状假设理论,由统计数据得出块体实际体积的对数和球形假设估算的块体体积的对数呈线性相关,应用回归分析推导出得到通过三维形状参数估算岩块体积的公式,通过实验对比,根据二维几何参数估算的块体体积和块度模型的块体实际体积的分布规律一致。

Blasting image analysis is the main method to study the ore-rock blasting fragmentation distribution. According to the two dimensional graphics of rock block obtained by image segmentation, techniques for estimating rock block volume from projection parameters is discussed. Based on the probability distributions of joint inclination, dip and spacing obtained by statistical analysis, three dimensional joints network is simulated through Monte Carlo method. Three dimensional model of ore rock original fragmentation cutting by joint planes was generated, and then it was sliced in 3 perpendicular orientations in order to get two dimensional contours corresponding to the blocks. For different value of two dimensional shape parameter φ, the variation of three dimensional shape parameters e and K were analyzed and the relationship among φ ,ε and K are established. The three dimensional fragmentation model is separated into 6 block sets using block shape classification method. According to the shape assumption theory, the es- timating values of block volume under sphericity assumption are liner correelated with the logarithm values of actual block volume. Furthermore, the estimating formula for block volume from two dimensional shape parameter and pro- jected area of block is derived by regression analysis. Through experimental comparison, it shows that the distribution of block volumes estimated by two dimensional shape parameter is consistent with the distribution of block volumes within fragmentation model.