深井动压影响下山煤巷围岩变形机理与控制研究

Study on mechanism and control of surrounding rock deformation of dip coal roadway affected by dynamic pressure in deep well

以刘桥一矿Ⅱ66回风下山为工程背景,采用现场实测、实验室实验、数值模拟和工业性试验综合分析了下山煤巷非对称变形破坏机理,提出动压影响下深井软弱煤巷围岩多层次组合控制理论,并给出优化控制措施。研究表明:回风下山变形失稳严重并呈非对称性,围岩完整性较差,强度低。地应力实测显示,回风下山处于高原岩应力区,最大主应力为水平应力且具有明显方向性,与巷道轴线夹角为71°,断面顶底板剪切破坏风险较大;数值模拟显示,回风下山开拓延伸期间,受邻近轨道下山、辅助下山影响显著,4煤回采对其影响较小,6煤工作面回采是下山煤巷非对称失稳的主要诱因;提出以围岩深浅孔注浆为核心,以新型注浆锚索、锚杆为装备基础的高阻让压全断面组合控制理论,并给出具体优化方案。工业性试验显示,下山煤巷围岩变形得到有效控制。

Taking Liuqiao No.1 coal mineⅡ66 return-air dip as the engineering background,the asymmetric deformation failure mechanism of dip coal roadway was comprehensively analyzed by using the field measurement,laboratory experiment,numerical simulation and industrial test.The multi-level combined control theory for the soft surrounding rock of coal roadway in deep well under the influence of dynamic pressure was put forward,and the optimization control measures were proposed.The results showed that the deformation and instability of return-air dip was serious and asymmetric,and the integrity of surrounding rock was poor,with the low strength.The measured in-situ stress showed that the return-air dip lay in the stress zone of the plateau rock.The maximum principal stress was the horizontal stress and had the obvious directivity,and its included angle with the roadway axis was 71°,so the shear failure risk of sectional roof and floor was large.The numerical simulation showed that during the development and extension periods of return-air dip,the influence by the adjacent track dip and auxiliary dip was significant,while the influence by the No.4 coal backstopping was little,and the No.6 coal working face backstopping was the main cause of asymmetric instability of the dip coal roadway.The combined control theory of high resistance yielding full section with the grouting of deep and shallow hole in surrounding rock as the core and the new grouting anchor rope and bolt as the equipment basis was put forward,and the specific optimization scheme was presented.The industrial tests showed that the deformation of surrounding rock of the dip coal roadway was effectively controlled.