Relationship between percolation and fractal properties of mining-induced crack network in coal and rock masses
Li Dongping●Zhou Hongwei●Xue Dongjie●Yi Haiyang●Gao Hailian
Abstract
The percolation and fractal theory are employed for analyzing evolution of the crack networks in the coal and rock masses at the site of the coal mining face No. 15-22060 at Mine No.8 of Pingdingshan Coal Mining Group. The evolving characteristics and corresponding relationship of percolation probability and fractal dimensions with advancement of the coal mining face are determined. The results show that, being controlled by initiation and propagation of transverse delamination fractures and vertical broken fractures, the permeability probability linearly increases in a stage-wise way with advancement of the coal mining face and the magnitude of amplification is increasing. The crack network propagates into the coal body ahead of mining face and the overburden strata with advancement of the coal mining face. The length, width, quantity and distribution of cracks play dominant roles in fractal dimensions, and evolution of fractal dimensions falls into 3 stages. Relationships between percolation probability and fractal dimensions of crack network in coal and rock masses can be fitted using a power function for the first stage and two linear functions for the second and the third stage. These results lay a foundation for determining the equivalent permeability of the crack networks in coal and rock masses.
煤岩体采动裂隙网络的逾渗与分形特征关系研究
栗东平●周宏伟●薛东杰●易海洋●郜海莲
摘 要
以平煤八矿己15-22060工作面为背景，引入逾渗和分形理论，分析了煤岩体裂隙网络的演化特征，得到了逾渗概率和分形维数随工作面推进度的变化规律及二者的变化关系。结果表明：逾渗概率的大小受横向离层裂隙和竖向破断裂隙的发育、贯通等因素影响，随工作面推进分阶段线性增大，且增幅有增大的趋势；随工作面推进煤岩体的裂隙网络逐步向工作面前方煤体和上覆岩层扩展，分形维数大小受裂隙的长度、宽度、数量、分布等因素控制，升维过程大致可分为3个阶段；煤岩体裂隙网络的逾渗概率与分形维数的关系可分段拟合为1个幂函数和2个线性函数，且具有很好的相关性，数学模型的建立可为研究煤岩体裂隙网络的等效渗透率奠定一定的基础。
引用格式：
Li DP,Zhou HW, Xue DJ, Yi HY, Gao HL. Relationship between percolation and fractal properties of mining-induced crack network in coal and rock masses[J]. Rock and Soil Mechanics, 2015, 36(4): 1135 -1140. 栗东平, 周宏伟, 薛东杰, 易海洋, 郜海莲. 煤岩体采动裂隙网络的逾渗与分形特征关系研究[J]. 岩土力学, 2015, 36(4):1135-1140.
DOI：10.16285/j.rsm.2015.04.030
文章连接地址：
No responses yet