College of Safety Science and Engineering, Xi’an University of Science and Technology
Key Laboratory of Western Mine Exploitation and Hazard Prevention of the Ministry of Education, Xi’an University of Science and Technology

钻孔瓦斯抽采是解决瓦斯超限问题的重要手段，受地应力、钻进扰动等影响矿井瓦斯抽采钻孔易塌孔变形，严重影响瓦斯治理效果。针对煤层瓦斯抽采钻孔塌孔位置难以监测的问题，提出了一种基于光纤光栅智能传感技术的钻孔塌孔监测技术。首先从光纤光栅传感器应力监测理论出发阐述了光纤光栅钻孔塌孔监测原理，在此基础上构建了基于光纤光栅的塌孔表征实验平台，开展了不同塌落煤量下3种光栅布置方式（0°、90°、180°）的钻孔塌孔监测模拟试验，研究了光栅测量波长偏移量、抽采流量随塌落煤量的变化规律，划分了钻孔塌孔等级。结果表明：光栅测点位于基体材料下方布置方式的塌孔监测准确度最高，此时中心波长偏移量Δλ与塌落煤量m的关系为$ m = 3.017Delta lambda $，抽采流量Q与波长偏移量Δλ的关系为$ Q = 8.72E{{ - }}7{{{x}}^{{3}}}{{ + 2}}{{.30}}E{{ - }}4{{{x}}^{{2}}}{{ - 0}}{{.18x + 30}} $。以抽采流量衰减率为塌孔评判标准划分三级塌孔标准：Ⅰ级塌孔抽采流量衰减至90%，Ⅱ级塌孔抽采流量从90%衰减至50%，Ⅲ级塌孔抽采流量衰减至50%以下。最后，通过在潞安集团漳村煤矿2802工作面的现场试验验证了光纤光栅塌孔监测技术的有效性，发现钻孔30 d后塌孔位置分布与钻孔打钻完成后的初期期情况相近；在现场试验中，基于所提出的塌孔监测技术成功定位并修复了5个钻孔，修复后钻孔瓦斯抽采纯量较未修复前提升了37.79%。

Drill hole gas extraction is an important method to solve the problem of gas overrun. However, the mine gas extraction drilling hole is prone to collapse and deformation due to the influence of ground stress and drilling disturbance, which seriously affects the effect of gas treatment. Aiming at the problem that it is difficult to monitor the location of collapsed hole in the gas extraction drillhole of coal seam, a monitoring technology for collapsed hole based on fiber grating intelligent sensing technology was proposed. Firstly, the principle of monitoring drilling hole collapse by fiber grating was explained from the theory of stress monitoring by fiber grating sensors. Based on this, an experimental platform for the hole collapse characterization based on fiber grating was built. The hole collapse monitoring experiments of three types of grating arrangements (0°, 90° and 180°) under different amount of collapsed coal were carried out, the changes of grating measurement wavelength offset and extraction flow rate with the amount of collapsed coal were studied, and the collapse level of drillhole was classified. The experimental results shown that, the accuracy of collapsed hole monitoring was the highest when the grating measurement point was located below the substrate material, the relationship between the central wavelength offset Δλ and the amount of collapsed coal m was $m = 3.017Delta lambda $, and the relationship between the extraction flow rate Q and the wavelength offset Δλ was $ Q = 8.72E - 7x^3 + 2.30E - 4x^2 - 0.18x + 30 $. The decay rate of extraction flow was used as the criterion of collapsing hole to divide the three levels of collapsed hole: Class I collapsed hole with the extraction flow decayed to 90%, Class II collapsed hole with the extraction flow decayed from 90% to 50%, and Class III collapsed hole with the extraction flow decayed to less than 50%. Finally, the effectiveness of fiber grating collapsed hole monitoring technology was verified through a field test in 2802 working face of Zhangcun coal mine of Lu'an Group, and it was found that the distribution of collapsed-hole locations after 30 days of drilling was similar to that of the initial period after the drilling was completed. In the field test, five drill holes were successfully located and repaired based on the proposed collapsed hole monitoring technique, and the pure volume of gas extraction from the repaired drill holes was improved by 37.79% compared to that before the repair.

国家自然科学基金面上资助项目(51974241，52174203)

张　超，程仁辉，黄晓昇，等. 基于光纤光栅的煤层瓦斯钻孔塌孔位置表征试验研究[J]. 煤炭科学技术，2023，51（11）：95−103.

ZHANG Chao，CHENG Renhui，HUANG Xiaosheng，et al. Experimental study on hole collapse characterization of gas drainage holes in this coal seam based on fiber bragg grating[J]. Coal Science and Technology，2023，51（11）：95−103.