巷道内强主动支护与弱结构卸压防冲协调机制

Coordination mechanism of internal strong active support,soft structure pressure relief and anti-punching of roadway

为探索深部冲击地压巷道稳定性控制技术,解决冲击地压巷道支护与卸压之间的矛盾,以义马矿区常村煤矿21170运输巷为研究对象,依据冲击地压巷道的强弱强结构模型,采用理论分析、数值模拟、现场试验相结合,分析了强弱强结构消波吸能特性以及内强小结构破坏能量准则和弱结构吸能效应。根据钻孔破碎区力学特征理论推导了多次反复致裂中间弱结构卸压区影响因素,多次反复致裂半径与钻孔半径、初始应力、内摩擦角、弹性模量、降模量、峰值强度和致裂半径修正系数有关。通过数值模拟分析了内强小结构内置钢管支撑护壁技术对巷道围岩的强度和支护体结构完整性控制效果以及周围煤岩体的应力、位移的破坏规律。研究了内强小结构主动支护强化技术,中间卸压防冲弱结构的内置套管反复掏裂致裂方法,并通过微震能量监测验证了弱结构防冲吸能效应。研究结果表明:内置钢管支撑护壁技术在保护内强小结构不受破坏的作用下可以多次进行弱结构致裂,既防内强小结构松动圈裂隙扩展,又防止巷道支护层的整体失稳。工程实践表明:锚杆索主动支护+液压抬棚减跨强力支护+卸压防冲弱结构组成的“内支-外卸”组合技术,微震监测显示震动能量减少了50%,巷道两帮位移和顶板下沉显著较小,有效维护了巷道围岩稳定性,保证了工作面顺利安全回采。

In order to explore the stability control technology of deep rockburst roadway,and to solve the contradiction between the support and the pressure relief impact on the roadway,taking the 21170 roadway of Changcun Coal Mine in Yima as an example,according to the strong-soft-strong structural model of roadway in the impact area,the theoretical analysis,numerical simulation and field test are used to analyze the energy absorption characteristics of strong-soft-strong structure,internal strong structure energy damage criterion and soft structure energy absorption effect.Based on the theory of the mechanical characteristics of the fractured zone of the borehole,the influencing factors of the pressure relief zone of the soft structure of repeated drilling are deduced.The repeated cracking radius is related to the drilling radius,initial stress,internal friction angle,elastic modulus,modulus reduction,peak strength,and drilling radius correction factor.Through the numerical simulation,the failure law of the strength of the surrounding rock of the roadway and the structural integrity control of the supporting body and the stress and displacement of the surrounding coal and rock body are analyzed by the internal steel pipe borehole protection technology.The strengthening technology of active support for internal strong structure and the method of repeated drilling caused by internal steel pipe in the pressure relief and control structure are studied.Through the monitoring of micro-seismic energy,the energy absorption effect of soft structure is verified.The internal steel pipe borehole protection technology can repeatedly drill the soft structure under protecting the internal strong structure from damage,not only prevents the crack expansion in the loose circle of the internal strong structure,but also prevents the overall instability of the supporting layer of the roadway.The engineering practice show that the anchor cable active support+hydraulic lifting shed reduction span strong support+soft structure energy absorption technology form an integrated technology of internal strong support structure and external soft pressure relief structure.The micro-seismic monitoring shows that the vibration energy is reduced by 50%,the displacement of the two sides of the roadway and the roof subsidence are significantly smaller,which effectively maintains the stability of the surrounding rock of the roadway and ensures the smooth and safe mining of the working face.The research results provide a reference for similar roadway anti-shock and support in the impact area.