坚硬顶板孤岛工作面巷道矿压显现机理及卸压孔技术实践

Study on Mechanism of Ore Pressure and Technical Parameters of Pressure Relief Hole in Isolated Working Face with Thick Hard Roof

基于晋能塔山矿8310厚层坚硬顶板孤岛工作面地质条件,采用理论研究、建模分析和工程实地测试结合的方法探究孤岛工作面矿压显现机理,分析卸压孔相关技术参数对巷道塑性区的影响。研究结果表明:孤岛工作面采场巷道受到一侧采空区影响,巷道应力集中、巷道变形现象明显;基于上覆关键层理论及简支梁模型判定,结合8310工作面上层覆岩结构计算得到老顶初次垮落极限步距为85.3 m,空间顶板垮落高度达到148.9 m;通过FLAC^(3D)数值模拟,基于卸压孔长度4 000 mm,间距1 500 mm,孔径φ120 mm参数方案施工后,巷道上层围岩完整性较好,巷道围岩变形未受到较大的应力集中影响。

Based on the geological conditions of the isolated working face of 8310 thick hard roof in Tashan mine of Jinneng coal industry, the mechanism of mine pressure appeared in the isolated working face was explored by means of theoretical research, modeling analysis and engineering field test, and the influence of related technical parameters of pressure relief hole on the roadway plastic zone was analyzed. The results show that the roadway stress concentration and roadway deformation are obvious due to the influence of goaf on one side.Based on the theory of overburden key layer and simply supported beam model, combined with the calculation of overburden structure of 8310 working face, the initial collapse limit step of old roof is 85.3 m, and the spatial roof collapse height is 148.9 m. Through FLAC^(3D)numerical simulation, after the construction of the parameter scheme based on the length of the pressure relief hole of 4 000 mm, spacing of 1 500 mm and aperture of 120 mm, the integrity of the upper surrounding rock of the roadway is better, and the deformation of the surrounding rock of the roadway is not affected by great stress concentration.