The control principle and technology of “one obstruct and three strengthen” of soft rock roadways below weak aquifers
WU Yongzheng, GUO Gangye, WANG Zhanling
针对弱含水层下软岩巷道围岩大变形难控制的问题，以清水营煤矿110207 运输巷为研究对象开展了研究工作。首先，依据现场调查与实测分析了巷道围岩的变形破坏特征，明确该巷道存在“一水三弱”的四大特征：即水与高比例黏土矿物并存、弱锚固基础、弱支护阻力扩散效能、弱围岩承载性能；其次，采用理论分析、数值模拟与现场实测的综合研究方法，揭示了巷道围岩的变形破坏机制，认为弱含水层下软岩巷道围岩变形破坏过程分为初始变形、急速变形与缓慢增长3 个阶段，3个阶段的变形量占比约为10%、30% 与60%，水的存在是导致该类巷道围岩后期变形缓慢增长的重要影响因素；最后，提出了针对该类巷道围岩“一隔三强”的稳定性控制原理与方法，即采取合适的方法隔断水与泥岩的接触通道，强化锚杆（索）锚固基础、强化锚杆（索）预紧力扩散表层与增强巷道围岩自身承载能力，并给出了相应的全断面“锚索+网+注浆+喷浆”的综合控制方案。将该方案付诸实践，现场实测表明：采用新方案后围岩裂隙封闭隔断了水与泥岩之间的接触通道，强化了锚索锚固力、预紧力扩散效能与围岩承载能力。矿压监测结果表明：巷道两帮最大移近量为51.9 mm，顶底板最大移近量为27.8 mm，保证了巷道的正常使用。研究成果较好解决了弱含水层下软岩巷道围岩的大变形问题，可为软岩巷道围岩稳定性控制提供一定的理论与技术参考。
Aiming at many problems about large deformation of surrounding rock of soft rock roadway below weak aquifers, the transportation roadway of coalface 110207 of Qingshuiying Mine is taken as an object to study a series of research works. Firstly, deformation and failure characteristics are analysised according to the field investigation and measurement. It is clear that there are four weaknesses in the roadway, which are the coexistence of water and high proportion of clay minerals, weak anchorage foundation, weak support resistance diffusion efficiency and weak bearing capacity. Secondly. Theoretical analysis, numerical simulation and field measurement have revealed the failure mechanism of the transportation roadway of coalface 110207, It is believed that the deformation and failure process of roadway surrounding rock under weak aquifer can be divided into three stages: initial deformation, rapid deformation and slow growth. The deformation in the three stages accounts for about 10%, 30% and 60%. The existence of water is an important factor affecting the slow growth of surrounding rock deformation in the later period of this type of roadway. Finally, the control method and principle of “one obstruct and three strengthen” is put forward, that is, appropriate methods are adopted to cut off the contact between water and mudstone, strengthen the anchoring foundation of the bolt and cable, strengthen the diffusion surface of the preload of the bolt cable and enhance the bearing capacity of the roadway surrounding rock, and the corresponding comprehensive control scheme of “cable + net + grouting + spray” is given. The field measurement shows that the surrounding rock fissure is closed to cut off the flow way of water, and the anchorage force of anchor cable is strengthened after grouting.The maximum displacement of the two sides of the roadway is 51.9 mm, and the maximum displacement of the roof and floor is 27.8 mm, which ensures the normal use of the roadway. The problem of large deformation of surrounding rock of soft rock roadway below weak aquifer can be better solved by the research results, and provide a certain reference for the stability control of the same type of roadway.
weak water； soft rock roadway； anchoring； roadway support； control of surrounding rock