采动岩体裂隙分维演化规律分析

Study on Cracks Fractal Evolution Laws of Mining Rock Mass

采用岩石破裂过程RFPA数值分析系统研究了具有初始裂隙的采动岩体裂隙演化过程和破坏模式,利用数值试验成果基于分形几何理论分析了采动岩体裂隙分形维数随开采宽度、初始损伤量的演化特征,揭示了采动岩体裂隙分维演化规律。分析证明,与采动岩体裂隙分布的分形维数存在明确对应关系的应为初始损伤量,而不是初始裂隙倾角,不同的初始损伤量对应不同的分形维数,在开采末期,采动岩体裂隙分维随初始损伤的增加而呈线性增加,回采结束时,初始损伤量越大,采动岩体裂隙分布的分形维数越大。研究结果为进一步探索裂隙随机分布时采动岩体分维演化规律提供参考依据。

Crack propagation process in the overlying strata with initial crack was studied by using the numerical test of rock failure RFPA. Mining width and initial damage using of numerical test results were analyzed based on the fractal geometry fractal dimension characteristics of cracks distribution. Fractal laws of cracks evolution in the overlying strata were obtained. Results show that there is a clear correspondence between fractal dimension and initial damage rather than initial crack inclination. Different amount of initial damage is corresponded to the different fractal dimension of cracks distribution. Especially in the mining ending stage, fractal dimension of rock fracture induced by mining with initial damage is increased linearly. The greater initial damage is that the greater the fractal dimension of cracks distribution when mining ending. A new way is provided for studying on fractal dimension of cracks distribution induced by mining when random distribution of cracks.