岩爆实验碎屑分类及其研究方法

CLASSIFICATION AND RESEARCH METHODS OF ROCKBURST EXPERIMENTAL FRAGMENTS

利用中国矿业大学(北京)岩爆过程模拟实验系统,进行一系列的应变岩爆实验。对岩爆碎屑不同尺度,可以采用不同方法提取其信息,包括对面积约为100mm2的中粒碎屑SEM(扫描电子显微镜)扫描,粗粒碎屑的断口表面形貌三维激光扫描和岩爆碎屑颗粒的尺寸特征测量。测量参数为质量、长度、宽度和厚度。为了便于对不同尺度的岩爆碎屑进行研究的方便,将岩爆碎屑分为粗粒、中粒、细粒和微粒4组,对不同粒组采用不同的研究方法。以花岗岩为例,介绍不同方法计算分形维数的过程及结果。采用倍分长度区间、SEM裂纹图像处理的二值法及小岛法进形分形维数计算时,其线性关系都较好,但不同方法计算获得的分维值不同。根据不同粒组的分形结果,可以分析不同尺度下的岩爆碎屑破碎程度,并为进一步研究岩爆过程的能量变化特征提供基础。

A serial of rockburst samples are tested under rockburst simulating system of China University of Mining and Technology, Beijing. Different methods may be used to obtain information of fragments, including scanning medium fragments with area about 100 mm^2 by SEM（scanning electronic microscope） and the large fragments by 3D laser scan technology and measuring fragments size. The measuring parameters include mass, length, width and thickness. In order to analyze fragments of different scales conveniently, fragments are divided into four classes including coarse, medium, fine and micro grains and corresponding research methods are defined. The calculated process and results of fractal dimensions with different methods are introduced with an instance of rockburst granite sample. The linear correlation is obvious when fractal dimensions are calculated by methods of double divided interval for measuring data, image process of binary and small island for 3D laser scan data calculation. The fractal dimensions are different when using different methods. Based on the fractal dimensions of different groups of fragments, the degree of crushing of every group of fragments can be analyzed and base data may be provided to further investigate characteristics of energy changing during rockburst.