回风石门软岩巷道变形破坏机理及其支护对策

针对煤矿回风石门出现严重底臌、折帮和顶沉等非线性大变形破坏现象,且难支护的问题,采用工程地质力学分析、数值模拟和现场试验研究相结合的研究方法,对巷道的变形破坏机理和支护对策进行了深入研究。结果表明,巷道的变形破坏受分子吸水膨胀、胶体膨胀、构造应力、重力、工程偏应力、软弱夹层、层理等多种因素影响,其变形力学机制为IABIIABDIIIBC型。针对该种类型的复合型变形力学机制,提出了相应的转化为单一型的技术对策,数值模拟结果表明该技术对策可有效控制巷道的大变形破坏;提出了恒阻大变形锚杆+金属网+底角注浆锚管+钢纤维混凝土耦合支护方案,现场应用效果良好。

Deformation and failure mechanism and support measures of the soft rock roadway in the air return laneway

Aiming at the problem that the air return laneway of coal mine with a series of nonlinear large deformation and failure phenomenon such as serious floor heaves，wall caving，and roof falling is difficult to support，the authors deeply studied the deformation and failure mechanism of the soft rock roadway，and support measures by combining the research methods of engineering geological mechanics analysis，numerical simulation analysis and engineering application.The results show that the deformations of the roadway are caused by the swelling force of molecular water absorption and colloid，tectonic stress，deviatoric stress，tectonic stress，gravity，engineering deviatoric stress，weak interlayers and bedding，and the deformation mechanical mechanism of the surrounding rock of the air return laneway is a kind of composite mechanical mechanism，named IABIIABDIIIBC type deformation mechanical mechanism.For the deformation mechanical mechanism of the roadway，the authors put forward a series of corresponding measures，and the numerical simulation results show that the technology can effectively curb the harmful deformation of the surrounding rock，and put forward a coupling support technique，which uses constant resistance large deformation bolts，metal nets，floor grouting bolts，and steel fiber reinforced concrete.