滕县煤田锦丘煤矿16煤顶板灰岩存在弱面夹层,其厚度、破坏形态及下位坚硬岩层物理力学性质对巷道顶板整体的破裂形态产生影响,且地应力场不明,周边部分矿井存在支护设计中未考虑该因素引发的冒顶现象。本研究针对锦丘煤矿16煤162-206下轨道巷顶板破碎、两帮煤体大变形问题,通过地应力测量、顶底板力学测试、顶板钻孔窥视等综合研究方法,探究了滕县煤田16煤的地应力特征、灰层顶板力学特征及弱面位置,改进支护方案。通过数值模拟分析3种改进支护方案控制围岩的变形特征,优选最佳支护方案。通过工程监测评价最优支护方案的有效性。结果表明:16煤顶板灰岩夹层位于1~2m深度内,特别是1.1~1.3m和1.8~2.0m范围;16煤最大主应力位于近水平方向,顶板受影响较两帮大,易发生较严重的剪切破坏,且顶板位移较两帮大。最大主应力以南东向为主,数值为16~20MPa;综合控制效果、劳动强度和支护成本,选择方案2作为下轨道巷最优支护方案;工程中安装测点16~20天后,巷道围岩变形逐渐趋于稳定,顶底板和两帮的最大变形量为38和67mm,验证了改进支护方案的有效性。

In Jinqiu coal mine of Tengxian coalfield, there is a weak interlayer in the limestone of the 16th coal seam roof. Its thickness, failure pattern, and the physical and mechanical properties of the underlying hard rock layer affect the overall fracture pattern of the roadway roof. Additionally, the in-situ stress field is unclear and some surrounding mines have experienced roof falls for lack of consideration of this factor in support design. This study aims to address the roof fragmentation and significant deformation of the coal bodies on both sides of the roadway at 162-206 lower track of the 16th coal seam in Jinqiu coal mine. Using in-situ stress measurements, mechanical testing of the roof and floor, and roof borehole inspections, we explored the in-situ stress characteristics, limestone roof mechanics, and weak interlayer positions in the 16th coal seam of Tengxian coalfield to improve the support scheme. Numerical simulations were conducted to analyze the deformation characteristics of the surrounding rock under three improved support schemes, and the best support scheme was selected. The effectiveness of the optimal support scheme was evaluated through engineering monitoring. The results indicate that the limestone interlayer in the roof of the 16th coal seam is within a depth of 1~2 meters, particularly between 1.1~1.3 meters and 1.8~2.0 meters. The maximum principal stress in the 16th coal seam is nearly horizontal. The roof is more affected than the sides, leading to more severe shear failure and larger roof displacement. The maximum principal stresses are predominantly southeast oriented with values of to MPa. Considering the overall control effect, labor intensity, and support cost, Scheme was chosen as the optimal support scheme for the lower track roadway. During engineering monitoring, the deformation of the surrounding rock in the roadway gradually stabilized to days after installing the measurement points. The maximum deformation of the roof and floor was mm and the maximum deformation of the sides was mm, thus verifying the effectiveness of the improved support scheme.