【摘要】 为研究煤层上覆岩层在采动影响下裂隙的演化规律,通过室内相似材料模拟实验模拟了上覆岩层裂隙演化的全过程。运用分形理论方法,从煤层开采进度、裂隙倾角演化以及区域裂隙分布特征等角度定量分析了采动过程中、采动结束后上覆岩层裂隙的演化规律。研究结果表明:随着工作面的推进,分形维数随采距的推进呈现升维阶段—降维阶段—平稳变维阶段三个阶段的变化特征。根据采动后上覆岩层裂隙场分形维数大小对采煤区域的影响,将采动影响上覆岩层裂隙场定性划分为4个区域:垮落裂隙区、压实裂隙区、垂向裂隙区和离层裂隙区。通过分析裂隙张开程度及分形维数大小得出,垮落裂隙区、垂向裂隙区是主要的导水通道,离层裂隙区以水平流动为主、导水性一般,压实裂隙区导水性最差。更多还原

【Abstract】 In order to study the evolution law of overburden rock fracture caused by mining,a laboratory simulation is undertaken to simulate the whole process of the evolution of the overlying rock fracture. Based on fractal theory,from the mining progress,the fracture angle evolution and the distribution characteristics of the regional fracture,the evolution of fracture is studied quantitatively. The result shows that with the advance of working face,the fractal dimension presents three stages of change,i. e. ascending dimension stage,dimension reduction stage and stationary stage. According to the influence of the fractal dimension on the mining area,the mining fracture field is divided into four areas,namely collapse fracture area,compacted fracture area,vertical fracture area and delamination fracture zone. Through the analysis of crack opening degree and the size of fractal dimension,it is realized that the collapse fracture area and vertical fracture area is the primary water conductor; the delamination fracture area is dominated by horizontal flow and the water conductivity is low; the hydraulic conductivity of compacted fracture area is the lowest.更多还原