覆岩采动裂隙网络分形演化规律研究

Research on crack network fractal evolution laws of mining covered rock

为了定量研究覆岩采动裂隙场演化规律,基于UDEC离散元的数值模拟方法,应用非线性分形几何理论,研究了采动岩体裂隙随开采宽度变化的动态演化规律。研究表明:采动覆岩裂隙的形成、发育与分布具有自相似性和分形特征,用分形维数可以定量描述采动岩体裂隙网络演化特征;随着采宽的增大,采动岩体分形裂隙网络的分形维数总体呈现增大的趋势,但不同阶段的增加幅度不同,根据增长幅度的大小分为2个阶段;第1阶段分形维数迅速上升,呈对数关系,为迅速升维阶段;第2阶段分形维数呈线性缓慢增长趋势,为缓慢升维阶段。研究成果为采动覆岩裂隙定量描述提供一定的理论与实践基础。

In order to study quantitatively the cracks fractal evolution laws of mining covered rock,based on the numerical method of UDEC,combined with nonlinear fractal geometry theory,the dynamic evolution of crack network with the changing of mining width were researched. The results showed that the formation and development and distribution of the mining covered rock crack have self-similarity and the fractal dimension can quantitatively describe the evolution characteristics of fractured rock mass network. The fractal dimension of mining rock mass showed an increasing trend,but the increasing extent was different in different stages. It was divided into 2 stages according to the size of the growth rate. In the first stage that was called the stage of rapidly increase dimension,the fractal dimension increased rapidly as a logarithmic relationship; the fractal dimension showed a linear slow growth trend in the second stage that was called the stage of slowly increase dimension. The results provide certain theory and the practice foundation for mining covered rock crack quantitative description.