大厚度泥岩顶板煤巷破坏机制及控制对策研究

 针对煤巷上方大厚度泥岩顶板在开挖支护后所表现的破坏现象，通过现场观察、室内试验、数值试验、相似模拟试验及理论分析，对其变形破坏机制及控制对策进行系统研究，动态分析围岩的变形和破坏过程，研究不同支护情况下巷道变形规律、破坏机制、应力分布及不同支护手段的加固效果。得出如下结论：(1) 泥岩风化崩解、碎裂扩容与应力调整过程中的高应力拉伸与剪切共同促使泥岩顶板破裂、离层和破碎的发生；(2) 原支护缺乏对围岩性质的准确判断导致巷道破坏与支护失效；(3) 大厚度泥岩顶板煤巷支护的原则：及时封闭围岩、提高下位岩层刚度、布置斜向锚索；(4) 根据地质力学与环境条件，通过断面优化及支护参数优化能够有效避免大厚度泥岩顶板煤巷的多次翻修，实现一次支护的长期稳定。研究成果在棋盘井矿区获得全面应用，对类似条件工程的支护技术具有一定的理论意义和实用价值。

DAMAGE MECHANISMS OF MUDSTONE ROOF WITH GREAT-THICK IN COAL ROADWAY AND ITS CONTROLLING COUNTERMEASURES

The deformation characteristics of surrounding rock after excavating and supporting of coal roadway with great-thick mudstone roof，its failure mechanism and its controlling countermeasures are systematically researched through field investigation，laboratory test，numerical testing，similar simulation and theoretical analysis. Meanwhile these methods are used to represent dynamically the process of rock deformation and failure in the roadways，and the roadway?s behaviors including deformation characteristics，failure mechanisms，stress distribution in the surrounding rocks and the effects of various support systems on roadway stability are studied. Some conclusions can be drawn as follows：(1) The fracture，cracking and separating layer of the thick mudstone roof occurred and promoted promote by two ways，such as the weathering，disintegrating，disruption，dilatancy of the mudstone，as well as the concentrated tensile stress and shear stress in the stress adjustment. (2) Based on the study，it is shown that the original supports in the absence of accurate judgment of the surrounding rock result in the roadway destruction and the supports system abated. (3) The principles to support the mudstone roof are enclosing in time，enhancing the stiffness of the lower rock layer of the roof and disposing the anchor cables along the cracks. (4) Based on the geological mechanics and environmental conditions of the roadway surrounding rock，an optimized roadway support design is provided that effectively avoid the multiple recondition by changing the cross-section and modulating the support parameters. The long-term stability of the thick mudstone roof had been realized. After several successful engineering practices，research results have been adopted in Qipanjing mining area；and the results have great theoretical and practical values to similar roadway supports.