麻地梁煤矿大采高综放工作面主动式超前支护技术应用

Application of active advanced support technology in fully mechanized top-coal caving face with large mining height at Madiliang Coal Mine

  • 摘要: 针对大采高综放工作面超前液压支架支护存在作业空间受限、劳动强度大等问题,以麻地梁煤矿507工作面辅助运输巷为研究对象,提出采用补强锚杆(索)主动式超前支护代替超前液压支架的支护方案。采用TS−C1201型矿用钻孔成像仪对煤岩体内部裂隙进行观测,结果显示507综放工作面回采巷道顶板浅部存在少量纵向裂隙,其余区域裂隙不发育,表明顶板整体完整性良好,具备实施主动式超前支护的条件。结合上述观测结果,设计锚杆(索)主动式超前支护方案:顶板采用“锚杆+锚索+钢带”联合支护,布置7根左旋无纵筋螺纹钢锚杆和3根锚索,配合M3型钢带;左帮布置4根全螺纹锚杆;右帮采用4根玻璃钢锚杆。理论计算结果表明,补强锚杆(索)主动式超前支护提升了支护系统强度,满足巷道超前段支护需求。数值模拟结果表明:507综放工作面回采期间,采用原主动式超前液压支架支护方案,超前工作面10 m范围出现明显的应力集中,垂直方向最大应力为4.5 MPa,顶板最大下沉量约为35 mm;超前工作面30 m范围,垂直方向最大应力约为5.5 MPa。采用锚杆(索)补强支护后,巷道垂直应力小幅度下降,巷道垂直应力场分布得到优化;在超前工作面10~30 m范围顶板最大下沉量无明显变化。可见,采用补强锚杆(索)主动式超前支护代替超前液压支架可满足超前支护要求。工业试验结果表明:补强锚杆(索)受力稳定,约为81 kN;巷道顶底板及两帮最大位移分别为41,37 mm,顶板无离层现象,满足安全生产需求。

     

    Abstract: In response to issues such as limited operating space and high labor intensity associated with advanced hydraulic support in fully mechanized top-coal caving faces with large mining height, this study takes the auxiliary transport roadway of the 507 working face in Madiliang Coal Mine as the research object and proposes a support scheme that uses active advanced support with reinforcement anchor cables to replace advanced hydraulic support. The TS-C1201 type borehole imaging device for mining was used to observe fractures within the coal and rock mass. The results showed that a small number of vertical fractures were present in the shallow part of the roof of the 507 top-coal caving face, while fractures were not developed in other areas, indicating that the overall roof integrity was good and the conditions were suitable for implementing active advanced support. Based on the above observation results, an active advanced support scheme using bolts (cables) was designed. A combined support system of “bolts + cables + steel strips” was adopted for the roof, with the installation of seven left-handed deformed-thread steel bolts without longitudinal ribs and three cables, in combination with M3-type steel strips. Four full-thread bolts were installed on the left sidewall, and four fiberglass bolts were installed on the right sidewall. Theoretical calculations indicated that the reinforcement anchor cables used in the active advanced support system enhanced the strength of the support system and met the support requirements for the advanced section of the roadway. Numerical simulation results showed that during the mining of the 507 fully mechanized top-coal caving face, under the original active advanced support scheme, significant stress concentration occurred within 10 meters ahead of the working face, with a maximum vertical stress of 4.5 MPa and a maximum roof subsidence of approximately 35 mm. Within 30 meters ahead of the working face, the maximum vertical stress reached approximately 5.5 MPa. After the implementation of reinforcement support with bolts (cables), the vertical stress in the roadway decreased slightly, and the distribution of the vertical stress field was optimized. However, there was no significant change in the maximum roof subsidence within the 10–30 m range ahead of the working face. These findings demonstrated that replacing advanced hydraulic supports with active advanced support using reinforcement bolts (cables) could meet the requirements for advanced support. Industrial test results showed that the reinforcement anchor cables remained stable under a load of approximately 81 kN. The maximum displacements of the roadway roof and floor, and of the two sidewalls, were 41 mm and 37 mm respectively. No separation was observed in the roof, indicating that the support scheme meets the requirements for safe production.

     

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