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超大采高综采工作面回撤通道支护技术研究

Study on support of retractable channel in fully-mechanized mining face with super large mining height

  • 摘要: 为实现榆神矿区8.2 m超大采高工作面大型设备安全高效回撤,以金鸡滩煤矿12-2108工作面回撤通道为工程背景,采用理论计算、数值模拟和现场矿压实测的方法,研究工作面末采阶段基本顶周期来压规律与顶板断裂位置,得出末采阶段基本顶周期来压步距19.3 m,工作面推进距主回撤通道7.9 m时受动压影响剧烈,在贯通前2 m处来压结束,运用停采等压技术证明工作面与回撤通道贯通时无须等压,同时确定基本顶下一次周期来压断裂位置位于主、辅回撤通道中间煤柱约4.8 m处,工作面最终实现了无来压贯通。基于采场矿压规律研究,回撤通道创新性地提出采用恒阻大变形锚索+钢带十字链接按A,B、C三个不同应力分区支护整体受力的新设计方法,通过现场实测应用得出: C区域的锚索伸长量大于B和A区域,越靠近工作面侧锚索下沉量越大,位于回撤通道中部(C区)靠近回采侧恒阻锚索最大延伸量达到180 mm,而垛式支架撤出后大断面巷道一侧邻空成悬臂梁,此时恒阻大变形锚索完全受力,回撤通道顶板整体向采空区倾斜的现象,证明支架撤出过程中恒阻锚索能够保持顶板临时稳定性,保证了顶板没有出现冒顶现象,底板、抹角、帮角基本没有变形,回撤通道围岩控制效果很好。8.2 m综采支架12 d完成设备整体撤架,实现了超大采高综采设备的安全高效回撤,为类似矿井提供了可靠的参考依据。

     

    Abstract: In order to realize the safe and efficient retraction of large-scale equipment in the 8.2 m super-high mining height working face in Yushen Mining Area, taking the retraction roadway of the No.12-2108 working face of Jinjitan Coal Mine as the engineering background, the methods of theoretical calculation, numerical simulation, and on-site mining pressure measurement were used to study the law of the basic top period of the working face during the last mining phase and the roof fracture position, it is concluded that the basic top period of the step distance is about 19.3 m in the final mining stage. The working pressure is severely affected by the dynamic pressure when the face advances 7.9 m from the main retraction roadway and the pressure is terminated at 2 m before roadway the drive-through. The isobaric technology of stopping mining is used to prove that the working face and the retraction roadway are connected without equal pressure. At the same time, it is determined that the location of the first cycle to pressure fracture is located at about 4.8 m in the coal pillar in the middle of the main and auxiliary retraction roadways, and the working face finally achieved drive-through without pressure. Based on the above mining pressure analysis and coal seam occurrence conditions, the retraction roadway innovatively proposes a new design method of using constant resistance large deformation anchor cable + steel strip cross link to support the overall stress zones of the A, B, and C. The actual measurement application shows: The anchor cable elongation in area C is greater than that in areas B and A. The closer the side of the working surface is, the greater the anchor cable subsidence is. The maximum extension of the constant resistance anchor cable located in the middle of the retraction roadway (C area) near the mining side reaches 180mm. After the stacking support is withdrawn, one side of the large-section roadway becomes a cantilever beam. At this time, the constant resistance and large deformation anchor cable is completely stressed, and the roof of the retraction roadway is inclined to the gob as a whole, which proves the constant resistance during the withdrawal of the support. The anchor cable can maintain the temporary stability of the roof, which ensures that the roof does not fall out, the bottom plate, corners and corners are basically not deformed, and the surrounding rock control effect of the retraction channel is very good. The 8.2m fully mechanized mining support completed the overall withdrawal of the equipment in 12 days, realizing the safe and efficient retraction of the fully mechanized mining equipment with super large mining height, and providing a reliable reference for similar mines.

     

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