煤炭工程 ›› 2023, Vol. 55 ›› Issue (6): 13-19.doi: 10. 11799/ ce202306003

• 设计技术 • 上一篇    下一篇

坚硬顶板深孔切顶卸压留窄煤柱护巷关键参数研究

陈立虎,王晓勇,霍一军,宁 飞,史建恩,邸旭峰   

  1. 1. 煤炭工业太原设计研究院集团有限公司,山西 太原 030001
    2. 国能神东煤炭集团有限责任公司 锦界煤矿,陕西 榆林 719319
  • 收稿日期:2022-12-21 修回日期:2023-02-13 出版日期:2023-06-20 发布日期:2023-06-30
  • 通讯作者: 陈立虎 E-mail:chenlihu_a@163.com

Study on key parameters of retaining narrow coal pillar for roadway protection with deep hole roof cutting and pressure relief in hard roof

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  • Received:2022-12-21 Revised:2023-02-13 Online:2023-06-20 Published:2023-06-30
  • Contact: lihu chenlihuchen E-mail:chenlihu_a@163.com

摘要:

针对坚硬顶板条件下窄煤柱及巷道围岩变形过大且矿压显现强烈的问题, 以付家焉煤矿10102 工作面回风巷为工程背景, 对坚硬顶板深孔预裂切顶留窄煤柱护巷参数进行研究。通过对顶板切顶护巷的力学推理分析, 切顶后顶板由初次来压前的三边固支、一边简支变成两边固支、两边简支, 使得顶板更易垮落且垮落步距相应降低, 缓和了工作面的矿压显现。对切顶留窄煤柱护巷的关键参数进行详细分析得出: 煤柱宽度、切顶角度、切顶深度、切顶炮孔间距是实现精准切顶的关键因素, 24 m 的垂直切顶深度完全的切断基本顶, 有效降低了基本顶的应力联系, 缩短基本顶悬臂长度的同时最大限度降低了煤柱的载荷。数值模拟结果表明, 8 m 煤柱不切顶时支承压力最大,达41. 8 MPa, 煤柱的塑形破坏最大, 甚至会导致煤柱留设失败; 8 m 煤柱切顶后, 煤柱的支承压力最小, 峰值为21. 2 MPa, 且煤柱内部压力集中区明显降低。切顶效果监测表明, 随着预裂切顶的进行, 对窄煤柱巷道的围岩控制起到了有效的作用。

关键词: 坚硬顶板, 窄煤柱, 切顶卸压, 深孔爆破, 矿压显现

Abstract:

Abstract:Aiming at the problem of excessive deformation of narrow coal column and roadway surrounding rock under hard roof conditions and strong mine pressure, the parameters of deep hole pre-cracked cutting roof and narrow coal column protection alley of hard roof were studied under the engineering background of Fujiayan Coal Mine 10102 working face return air lane. Through the mechanical reasoning analysis of the roof cutting and protection alley, the roof plate after the roof is cut from the three-sided solid support and one side simple branch before the initial pressure to the two sides of the solid support and the two sides of the simple branch, which makes the roof more likely to collapse and the collapse step distance is correspondingly reduced, which eases the mine pressure of the working face. The key parameters of the narrow coal column protection alley of the cutting roof are analyzed in detail: the width of the coal column, the cutting top angle, the cutting depth of the cutting roof, and the spacing of the cutting top gun hole are the key factors to achieve accurate top cutting, and the vertical cutting depth of 24m completely cuts off the basic top limestone, which effectively reduces the stress connection of the basic roof, shortens the length of the basic top cantilever and minimizes the load of the coal column. The numerical simulation results show that the supporting pressure of the 8m coal column is the largest when the top is not cut, reaching 41.8MPa, and the shaping damage of the coal column is the largest, which will even lead to the failure of the coal column; after the 8m coal column is cut to the top, the supporting pressure of the coal column is the smallest, the peak value is 21.2MPa, and the internal pressure concentration area of the coal column is significantly reduced. The monitoring of the roof cutting effect showed that with the progress of pre-cracking and cutting the roof, the cycle of the return air side bracket was stable and the time was short, indicating that the roof cutting and unloading technology made the structural connection of the roof plate change significantly, and the stress transmission of the basic top was discontinuous, which reduced the load above the narrow coal column and played an effective role in the surrounding rock control of the narrow coal column roadway.

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