裂隙岩体巷道大变形特征与稳定性控制

Large deformation characteristics and stability control of roadway with fractured rock mass

针对木孔矿深部裂隙岩体变形巷道围岩的稳定性及控制问题,采用现场调研与测试、实验室力学试验、理论分析和现场试验相结合的方法,分析+600 m(东翼)运输大巷围岩变形的主要影响因素。研究结果表明,该段巷道变形较大,应力环境复杂,围岩内部呈分区破裂形式分布,节理裂隙比较发育,为碎裂状结构类型。岩石力学试验结果表明,岩石的力学性质差异明显,岩体受到构造或结构面的影响较大;对该巷道的典型地段进行稳定性分级及描述,稳定性类别大多为V或IV类。因此,结合巷道围岩变形特点提出综合控制原则及关键技术,工程实践中采用"分次强化支护,实现内外承载"为核心的"锚杆、锚索和两步注浆壳体"联合支护技术,监测结果表明,新支护后的巷道围岩变形在可控范围之内,最终变形速度均未达到0.2 mm/d。

To solve the rock stability and control issues around deep roadway with fractured rock mass in Mukong coalmine, the main factors affecting the rock deformation in + 600 m(east wing) main haulage roadway were analyzed through adopting multiple methods of field survey and test, laboratory mechanics test, theoretical analysis and field experiments. Results show that the roadway tends to experience large deformation. The stress distribution is complex and surrounding rocks distribute in the form of zonal rupture. Meanwhile, the joint fissure develops well, forming the cataclastic structure. Rock mechanics test results show that the mechanical properties of rock are obviously different, and the rock mass is greatly affected by structures or structural planes. At the same time, the stability of some typical sections in the roadway are graded and described, which are mostly V or IV. Therefore, the comprehensive control principle and key technologies were put forward based on the deformation characteristics of roadway surrounding rock. In the engineering practice, "the bolt, cable and two-stage grouting shell"combined support technology were carried out. This technology focuses on "sub-strengthening support and internal & external bearing". According to the monitoring results, the deformation of roadway surrounding rock after adopting new support technique is within a controllable range, with the final deformation rate being less than 0.2 mm/d.