Coal Industry Taiyuan and Research Institute Group Co. , Ltd.
CHN Energy Shendong Jinjie Coal Mine

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,24m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,8m煤柱不切顶时支承压力最大,达41.8MPa,煤柱的塑形破坏最大,甚至会导致煤柱留设失败;8m煤柱切顶后,煤柱的支承压力最小,峰值为21.2MPa,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。

Aiming at the excessive deformation of narrow coal pillar and roadway surrounding rock under hard roof and strong mine pressure, the parameters of deep hole pre-splitting roof cutting and narrow coal pillar roadway protection of hard roof are studied under the engineering background of 10102 working face return air way in Fujiayan Coal Mine. According to the mechanical analysis of the roof cutting and roadway protection, after cutting, the roof changes 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 caving interval is reduced, thus the mine pressure behavior is alleviated in the working face. The key parameters for accurate top cutting are analyzed in detail, including the coal pillar width, roof cutting angle, cutting depth, and spacing of the blasting holes. And with the vertical cutting depth of 24 m, the main roof limestone is completely cut off, which effectively reduces the stress connection of the main roof, shortens the length of the main roof cantilever and minimizes the load of the coal pillar. The numerical simulation results show that the supporting pressure of the 8m coal pillar is the largest when the roof is not cut, reaching 41. 8 MPa, and the plastic damage of the coal pillar is the largest, which will even lead to the failure of the coal pillar; after the roof cutting, the supporting pressure of the coal pillar is the smallest, the peak value is 21. 2 MPa, and the internal pressure concentration area of the coal pillar is significantly reduced. The monitoring of the roof cutting effect showed that with the progress of pre-splitting and cutting of the roof, the cycle of the return air side support is stable and the time is short, improves the surrounding rock control.

陈立虎, 王晓勇, 霍一军, 等. 坚硬顶板深孔切顶卸压留窄煤柱护巷关键参数研究 [J]. 煤炭工程, 2023, 55(6): 13-19.