1. State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing　 400030,China;2. College of Resources and Environ-mental Sciences,Chongqing University,Chongqing　 400030,China;3. State and Local Joint Engineering Laboratory of Methane Drainage in Complex Coal Gas Seam,Chongqing　 400030,China

利用自行研制的"多场耦合煤矿动力灾害大型模拟试验系统",根据中国平煤神马集团十矿己15煤层24080工作面的地质资料,在三向不等应力条件下进行了三维模拟开采试验。通过应力监测、色素示踪、照相素描等手段,统计了各水平、垂直切面的裂隙形态、数量与分布特征,并建立了采空区覆岩裂隙网络数值模型。研究结果表明:三维应力条件下,采空区覆岩裂隙在空间上呈"类梯形台"形态,在低位岩层中呈"圆角矩形"形态,在中高位岩层则呈"O型"形态。按瓦斯运移难易程度可将覆岩裂隙分为以"纵向贯通裂隙"为主的直接流动通道和以"层内破断裂隙-层间离层裂隙-层内破断裂隙"方式延伸的间接流动通道。

Using self-developed “ multi-field coupling coal mine dynamic disaster simulation test system”,a three-di- mensional simulation excavating experiment was conducted based on the geological data from 24080 working face in Pingdingshan Coal Mine,China. Depending on the stress monitoring,pigment tracer,photographic sketch means,the statistics of fracture morphology,number and distribution characteristics in horizontal and vertical sections were ana- lyzed,then the overburden strata fracture network model was constructed. The research results show that:under true tri- axial stress condition,the fracture network in strata above the goaf presents a “ similar-trapezoidal platform” form in space,in the lower strata,presents a rounded rectangle shape,while in higher strata it tends to an “O shape” morphol- ogy. According to the degree of difficulty of gas migration,the overburden rock fracture network can be divided into primary and secondary flow channels.

国家重点基础研究发展计划(973)资助项目(2011CB201203)；国家自然科学基金资助项目(51434003,51374256)；

Yin Guangzhi,Li Xing,Han Peibo,et al. Experimental study on overburden strata fracture evolution law in three dimensional mine-induced stress conditions[J]. Journal of China Coal Society,2016,41(2):406-413.