集贤煤矿切顶留巷关键参数及留巷稳定性分析

    Key parameters and stability analysis of roof cutting and roadway retaining in Jixian Coal Mine

    • 摘要: 针对双鸭山集贤煤矿东二采区16#右三工作面切顶留巷难题,建立了切顶留巷围岩力学模型,给出了切顶高度、切顶角度等关键参数理论计算式;分析了切顶参数(切顶高度、切顶角度)对留巷围岩应力分布及变形特征影响规律。模拟结果表明:切顶高度越大,卸压效果越好;切顶角度增大,实体煤侧应力呈现增大趋势,同时也为矸石垮落创造一定条件。相似模拟结果表明:当煤层开采至一定距离时,采空区上位岩层同期垮落,切缝范围岩体和垮落岩体形成铰接,即巷旁充填基本完成,留巷上方形成“低位悬臂梁+高位铰接岩梁”结构。实践结果表明:切顶高度8.0 m(即切断2.39 m的中砂岩),切顶角度10°,切顶钻孔排距600 mm,距工作面60 m左右时,顶板下沉量为168 mm,实体煤帮移近量212 mm,矸石帮变形量几乎为0,底鼓量120 mm。

       

      Abstract: Aiming at the problem of cutting roof and retaining roadway on the right third working face of 16#, east second mining area of Jixian Coal Mine in Shuangyashan city, the mechanical model of surrounding rock of cutting roof and retaining roadway is established, and the theoretical calculation formula of key parameters such as cutting height and cutting angle is given; the influence of roof cutting parameters (roof cutting height and angle) on the stress distribution and deformation characteristics of the surrounding rock is further analyzed. The numerical simulation results show that the greater the roof cutting height is, the better the relief effect is; with the increase of the cutting angle, the side stress of solid coal shows an increasing trend, which also creates certain conditions for the caving of gangue. The similar simulation results show that when the coal seam is mined to a certain distance, the upper rock stratum in the goaf collapses at the same time, and the rock mass in the slit range and caving rock mass form a hinged joint, that is, the side filling of the roadway is basically completed, and the structure of “low cantilever beam + high hinged rock beam” is formed above the roadway. The engineering practice show that the cutting height is 8.0 m (2.39 m medium sandstone), the cutting angle is 10°, and the spacing of the drilling holes is 600 mm. When it is about 60 m away from the working face, the roof subsidence is 168 mm, the solid coal wall displacement is 212 mm, the deformation of the gangue wall is almost 0, and the bottom heave is 120 mm.

       

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