切顶留巷开采技术在煤炭开采过程中的应用日益广泛，但针对切顶留巷开采两相邻工作面开采完毕后，形成贯通采空区，卸压瓦斯在贯通采空区内的分布特征以及卸压瓦斯治理技术需进一步研究。本文以黄陵矿区某矿切顶留巷首采及次采工作面为背景，采用二维物理相似模拟实验、三维数值模拟实验对切顶留巷工作面开采形成贯通采空区前后覆岩应力分布、裂隙演化规律展开研究，得到了采空区渗透率分布规律，基于此建立了“Y”型通风下采空区流场数值模型，研究了采场漏风规律及卸压瓦斯分布特征，提出了切顶留巷下卸压瓦斯重点治理区域，并根据工作面实际情况设计了瓦斯治理方案，对抽采数据进行监测与分析，现取得以下研究结果：

通过物理相似模拟实验研究了切顶留巷下首采工作面覆岩运移及裂隙分布规律，得到采空区冒落带高度10 m，裂隙带高度55 m，切眼侧垮落角小于工作面侧；倾向方向切顶侧垮落角大于未切顶侧，切顶侧离层率与穿层裂隙密度略大于未切顶侧，离层裂隙区宽度小于未切顶侧。

利用3DEC数值模拟研究了贯通采空区形成过程以及采空区渗透率分布规律，冒落带顶板垮落形态为半矩形结构，裂隙带顶板垮落形态呈“O”型分布；冒落带渗透率曲面呈不规则“铲”状分布，未切顶一侧渗透率低于切顶一侧；而在裂隙带未切顶一侧渗透率高于切顶一侧；

基于渗透率模型建立“Y”型通风下采空区流场数值模型，得到了卸压瓦斯主要分布在采空区深部，按瓦斯浓度分为低浓度区、快速上升区、高浓度稳定区；后巷端头为瓦斯容易聚集超限区域；进风巷配风量对采空区卸压瓦斯浓度分布特征影响较大，辅运巷对后巷卸压瓦斯浓度分布特征影响较大。

基于以上研究结果，对切顶留巷采空区卸压瓦斯治理方案进行设计，建立了高位定向钻孔、跨工作面定向长钻孔、后巷抽采钻孔联合促抽方案，通过监测钻孔抽采效果、后巷及隅角瓦斯浓度、工作面风量等数据对抽采效果进行验证。生产过程中，工作面及后巷瓦斯均在安全范围内，实现了工作面的安全高效开采。该研究可为切顶留巷下高瓦斯矿井瓦斯治理提供借鉴，对矿井高效安全开采具有重要意义。

The application of roof cutting technology in coal mining process is becoming more and more widespread, but for the roof cutting mining two neighboring working face mining is completed, the formation of through-mining area, the distribution characteristics of unloaded gas in the through-mining area and unloaded gas management technology need to be further researched. This paper takes the first and second mining face of a mine in Huangling mining area as the background, and adopts two-dimensional physical similarity simulation experiments and three-dimensional numerical simulation experiments to study the stress distribution and fissure evolution law of the overlying rock before and after the formation of through-mining zone by mining of roof cutting cutting face, and obtains the distribution law of the permeability of the mining zone, and based on which, we establish the flow field of the mining zone under the “Y” type ventilation, and the flow field of the mining zone under the “Y” type ventilation. Based on this, a numerical model of the flow field in the void area under “Y” type ventilation was established, the air leakage law and the distribution characteristics of the unloaded pressure gas in the quarry were studied, and the key management area of the unloaded pressure gas under the roof-cutting and stay-along lane was put forward, and the gas management program was designed according to the actual situation of the working face, and the extraction data were monitored and analyzed, and the following research results were obtained:

The physical similarity simulation experiment was used to study the overburden rock transport and fissure distribution law of the first mining face under the roof cutting and stay lane, and the height of the fallout zone of the hollow area was 10 m, the height of the fissure zone was 55 m, the collapse angle of the eye side was smaller than that of the working face side; the collapse angle of the top-cutting side in the direction of inclination was larger than that of the roof-cutting side, the rate of the off-layer and the density of the penetrating fissure of the top-cutting side were slightly larger than that of the roof-cutting side, and the width of the off-layer fissure zone was smaller than that of the roof-cutting side.

3DEC numerical simulation was used to study the formation process of the through-mining zone and the distribution law of permeability of the zone, the top plate of the fallout zone collapsed in a semi-rectangular structure, and the top plate of the fissure zone collapsed in an “O” distribution; when the face advances to 160m, the height of the overlying rock plastic zone development has basically not changed; the permeability of the fallout zone is irregularly “shoveled”. The surface is irregularly “shovel”-shaped distribution, the permeability of the uncut roof side is lower than that of the roof cutting side; while the permeability of the uncut roof side in the fissure zone is higher than that of the roof cutting side;

Based on the permeability model, a numerical model of the flow field in the mining area under “Y”-type ventilation was established, and it was obtained that the unpressurized gas was mainly distributed in the deep part of the mining area, which was divided into the low concentration area, the rapidly rising area, and the high concentration stabilization area according to the gas concentration; the end of the back alley was the area in which gas was easy to gather and exceeded the limitation limit; the air volume of the air inlet alley had a greater influence on the distribution characteristics of the unpressurized gas concentration in the mining area; the auxiliary transportation alley had a greater influence on the distribution characteristics of the back alley. The air distribution volume of the air intake lane has a greater influence on the distribution characteristics of the unpressurized gas concentration in the mining area, and the auxiliary transportation lane has a greater influence on the distribution characteristics of the unpressurized gas concentration in the rear lane.

Based on the results of the above study, a program was designed to control the decompression of gas in the airspace of the roof cutting lane, and a joint program of high directional drilling, long directional drilling across the working face, and back-alley extraction drilling was set up to promote the extraction, and the effectiveness of the extraction was verified by monitoring the effect of the drilling, the concentration of gas in the back-alley and the corner, and the airflow of the working face. During the production process of the working face, there was no over-limit phenomenon caused by high gas concentration, and the safe and efficient mining of the working face was realized. This study can provide a reference for the gas management of high gas mines under roof cutting, which is of great significance for the efficient and safe mining of mines.

[1] 王双明, 刘浪, 朱梦博, 等. “双碳”目标下煤炭绿色低碳发展新思路[J]. 煤炭学报, 2024,49(01):152-171.

[2] 郝宇, 张宗勇, 廖华. 中国能源“新常态”:“十三五”及2030年能源经济展望[J]. 北京理工大学学报, 2016,18(02):1-7.

[3] 王双明, 申艳军, 宋世杰, 等. “双碳”目标下煤炭能源地位变化与绿色低碳开发[J]. 煤炭学报, 2023,48(07):2599-2612.

[4] Xu C, Ma S, Wang K, et al. Stress and permeability evolution of high-gassy coal seams for repeated mining[J]. Energy, 2023,284(05):102-117.

[5] 朱珍, 何满潮, 王琦, 等. 柠条塔煤矿自动成巷无煤柱开采新方法[J]. 中国矿业大学学报, 2019,48(01):46-53.

[6] 何满潮, 陈上元, 郭志飚, 等. 切顶卸压沿空留巷围岩结构控制及其工程应用[J]. 中国矿业大学学报, 2017,46(05):959-969.

[7] Manchao H, Yubing G, Jun Y, et al. An Innovative Approach for Gob-Side Entry Retaining in Thick Coal Seam Longwall Mining[J]. Energies, 2017,10(11):1785-1791.

[8] 王炯, 朱道勇, 宫伟力, 等. 切顶卸压自动成巷岩层运动规律物理模拟实验[J]. 岩石力学与工程学报, 2018,37(11):2536-2547.

[9] A. G, V. V, R. N G. Extraction of Coal Under a Surface Water Body-a Strata Control Investigation[J]. Rock Mechanics and Rock Engineering, 2005,38(5):52-63.

[10] WU Chao-fan W W Y W, Beijing Polytechinc College B C, Institute Of Geomechanics C A O G. Surveying on two-zone height of sublevel strip mining[J]. Journal of Coal Science & Engineering(China), 2010,16(02):129-134.

[11] Jincai Z, Baohong S. Coal mining under aquifers in China: a case study[J]. International Journal of Rock Mechanics and Mining Sciences, 2003,41(4):11-19.

[12] Kim J M. Fully coupled poroelastic governing equations for groundwater flow and solid skeleton deformation in variably saturated true anisotropic porous geologic media[J]. Geosciences Journal, 2004,8(3):108-121.

[13] 李志华, 杨科, 华心祝, 等. 采场覆岩“宏观-大-小”结构及其失稳致灾机理[J]. 煤炭学报, 2020,45(S2):541-550.

[14] 宋振骐. 实用矿山压力控制[M]. 中国矿业大学出版社, 1988.

[15] 钱鸣高. 岩层控制的关键层理论[M]. 中国矿业大学出版社, 2000.

[16] 茅献彪, 钱鸣高, 缪协兴. 采动覆岩中关键层的复合效应分析[J]. 矿山压力与顶板管理, 1999,1(Z1):19-21.

[17] 陶志刚, 谢迪, 隋麒儒, 等. 复杂地质条件下隧道围岩大变形负泊松比锚索主动支护方法及控制效果研究[J]. 岩石力学与工程学报, 2024,43(02):275-286.

[18] 何满潮. 无煤柱自成巷开采理论与110工法[J]. 采矿与安全工程学报, 2023,40(05):869-881.

[19] 张赛一, 王炯, 马新根, 等. 益新矿切顶卸压切缝参数优化研究[J]. 煤矿现代化, 2019(02):133-135.

[20] 高玉兵, 王琦, 杨军, 等. 特厚煤层综放开采邻空动压巷道围岩变形机理及卸压控制[J]. 煤炭科学技术, 2023,51(02):83-94.

[21] 贾后省, 王林, 彭博, 等. 弱黏结复合顶板沿空留巷分级“控顶-卸压”机理与应用[J]. 中国矿业大学学报, 2023,52(06):1191-1202.

[22] 何满潮, 盖秋凯, 高玉兵, 等. 坚硬顶板无煤柱自成巷碎胀平衡机理与调控研究[J]. 中国矿业大学学报, 2023,52(05):831-844.

[23] Zhongchang W, Wenrui B. Analysis of Pressure Relief Effect on the Protective Layer of Hard Roof and Extra-Thickness Coal Seam Mining[J]. Geotechnical and Geological Engineering, 2019,37(1):163-172.

[24] 郭俊良. 水力压裂切顶卸压技术在沿空巷道中的应用[J]. 煤炭与化工, 2019,42(01):47-49.

[25] 王炯, 朱道勇, 宫伟力, 等. 切顶卸压自动成巷岩层运动规律物理模拟实验[J]. 岩石力学与工程学报, 2018,37(11):2536-2547.

[26] 林海飞, 刘思博, 双海清, 等. 沿空留巷开采覆岩裂隙演化规律及卸压瓦斯抽采技术[J]. 采矿与岩层控制工程学报, 2024,6(01):52-64.

[27] 刘红威, 赵阳升, REN Tingxiang, 等. 切顶成巷条件下采空区覆岩破坏与裂隙发育特征[J]. 中国矿业大学学报, 2022,51(01):77-89.

[28] 钱鸣高, 许家林. 覆岩采动裂隙分布的“O”形圈特征研究[J]. 煤炭学报, 1998,23(05):466-469.

[29] 李树刚, 石平五, 钱鸣高. 覆岩采动裂隙椭抛带动态分布特征研究[J]. 矿山压力与顶板管理, 1999,3(Z1):44-46.

[30] 杨科, 谢广祥. 采动裂隙分布及其演化特征的采厚效应[J]. 煤炭学报, 2008(10):1092-1096.

[31] 林海飞, 李树刚, 成连华, 等. 覆岩采动裂隙带动态演化模型的实验分析[J]. 采矿与安全工程学报, 2011,28(02):298-303.

[32] Guo W, Zhao G, Lou G, et al. A New Method of Predicting the Height of the Fractured Water-Conducting Zone Due to High-Intensity Longwall Coal Mining in China[J]. Rock Mechanics and Rock Engineering, 2019,52(8):2789-2802.

[33] Cun Z, Shihao T, YiXin Z. Compaction characteristics of the caving zone in a longwall goaf: a review[J]. Environmental Earth Sciences, 2019,78(1):27.

[34] 双海清. 缓倾斜煤层采动卸压瓦斯储运优势通道演化机理及应用[D]. 西安科技大学, 2017.

[35] 李树刚, 刘李东, 赵鹏翔, 等. 综采工作面覆岩压实区裂隙动态演化规律影响因素分析[J]. 煤炭科学技术, 2022,50(01):95-104.

[36] 赵鹏翔, 刘李东, 李树刚, 等. 煤层倾角对仰斜工作面覆岩压实区裂隙演化规律的影响[J]. 煤炭科学技术, 2021,49(11):65-72.

[37] 赵毅鑫, 刘文超, 张村, 等. 近距离煤层蹬空开采围岩应力及裂隙演化规律[J]. 煤炭学报, 2022,47(01):259-273.

[38] 周世宁. 瓦斯在煤层中流动的机理[J]. 煤炭学报, 1990,15(01):15-24.

[39] 杨其銮, 王佑安. 煤屑瓦斯扩散理论及其应用[J]. 煤炭学报, 1986,12(03):87-94.

[40] 杨其銮, 王佑安. 瓦斯球向流动的数学模拟[J]. 中国矿业学院学报, 1988,1(03):55-61.

[41] 张少龙, 李树刚, 宁建民, 等. 开采不同厚度上保护层对下伏煤层卸压瓦斯渗流特性的影响[J]. 辽宁工程技术大学学报, 2013,32(05):587-591.

[42] 许江, 苏小鹏, 彭守建, 等. 卸压区不同钻孔长度抽采条件下瓦斯运移特性试验[J]. 岩土力学, 2018,39(01):103-111.

[43] 魏宗勇, 李莉, 李树刚, 等. 覆岩采动裂隙中瓦斯运移三维实验台的研制与应用[J]. 煤矿安全, 2015,46(07):5-8.

[44] 龚选平, 武建军, 李树刚, 等. 低瓦斯煤层高强开采覆岩卸压瓦斯抽采合理布置研究[J]. 采矿与安全工程学报, 2020,37(02):419-428.

[45] Ting L, Baiquan L, Xuehai F, et al. Experimental study on gas diffusion dynamics in fractured coal: A better understanding of gas migration in in-situ coal seam[J]. Energy, 2020,195(12):123-131.

[46] Ang L, Peng L, Shimin L. Gas diffusion coefficient estimation of coal: A dimensionless numerical method and its experimental validation[J]. International Journal of Heat and Mass Transfer, 2020,162(13):1459-1468.

[47] 赵洪宝, 李金雨, 刘一洪, 等. 不透气夹矸层对煤层瓦斯运移特性影响研究[J]. 采矿与安全工程学报, 2020,37(04):852-860.

[48] Haidong C, Yuanping C, Tingxiang R, et al. Permeability distribution characteristics of protected coal seams during unloading of the coal body[J]. International Journal of Rock Mechanics and Mining Sciences, 2014,71(3):105-116.

[49] Guangyao S, Ji-Quan S, Sevket D, et al. Monitoring and modelling of gas dynamics in multi-level longwall top coal caving of ultra-thick coal seams, Part II: Numerical modelling[J]. International Journal of Coal Geology, 2015,144-145(4):58-70.

[50] Fangtian W, Cun Z, Ningning L. Gas Permeability Evolution Mechanism and Comprehensive Gas Drainage Technology for Thin Coal Seam Mining[J]. Energies, 2017,10(9):108-115.

[51] 蒋金泉, 王普, 郑朋强, 等. 高位硬厚岩层下采动裂隙和支承应力演化特征及其对瓦斯运移的影响[J]. 采矿与安全工程学报, 2017,34(04):624-631.

[52] 王伟, 程远平, 刘洪永, 等. 基于sigmoid函数的采空区渗透率模型及瓦斯流场模拟应用[J]. 采矿与安全工程学报, 2017,34(06):1232-1239.

[53] 高保彬, 李回贵, 王晓蕾. 下保护层开采保护效果与瓦斯运移规律[J]. 辽宁工程技术大学学报, 2013,32(10):1319-1323.

[54] C. Ö K, G. S E, S. J S, et al. Reservoir simulation-based modeling for characterizing longwall methane emissions and gob gas venthole production[J]. International Journal of Coal Geology, 2006,71(2):225-245.

[55] 罗振敏, 王子瑾, 苏彬, 等. 基于FLUENT的采空区瓦斯运移规律数值模拟研究[J]. 矿业安全与环保, 2020,47(03):17-21.

[56] 洛锋, 曹树刚, 李国栋, 等. 采动应力集中壳和卸压体空间形态演化及瓦斯运移规律研究[J]. 采矿与安全工程学报, 2018,35(01):155-162.

[57] 林海飞, 李树刚, 赵鹏翔, 等. 我国煤矿覆岩采动裂隙带卸压瓦斯抽采技术研究进展[J]. 煤炭科学技术, 2018,46(01):28-35.

[58] 康建宏, 邬锦华, 李绪明, 等. 采空区高抽巷及埋管抽采下瓦斯分布规律研究[J]. 采矿与安全工程学报, 2021,38(01):191-198.

[59] 李一波, 郑万成, 王凤双. 顶板走向高抽巷瓦斯抽采效果分析[J]. 矿业安全与环保, 2013,40(03):74-76.

[60] 郝家兴. 基于覆岩裂隙带发育高度的走向高抽巷合理位置确定[J]. 中国安全生产科学技术, 2020,16(07):75-81.

[61] 袁亮, 郭华, 李平, 等. 大直径地面钻井采空区采动区瓦斯抽采理论与技术[J]. 煤炭学报, 2013,38(01):1-8.

[62] 耿铭, 徐青云. 塔山矿地面L型钻孔抽采瓦斯技术应用[J]. 煤炭工程, 2019,51(12):82-85.

[63] Cun Z, Shihao T, Lei Z, et al. A methodology for determining the evolution law of gob permeability and its distributions in longwall coal mines[J]. Journal of Geophysics and Engineering, 2016,13(2):181-193.

[64] 李树刚, 徐培耘, 林海飞, 等. 倾斜煤层卸压瓦斯导流抽采技术研究与工程实践[J]. 采矿与安全工程学报, 2020,37(05):1001-1008.

[65] 蔡文鹏, 刘健, 孙东生, 等. 顶板走向高位钻孔瓦斯抽采技术的研究及应用[J]. 中国安全生产科学技术, 2013,9(12):35-38.

[66] 李霄尖, 姚精明, 何富连, 等. 高位钻孔瓦斯抽放技术理论与实践[J]. 煤炭科学技术, 2007(04):16-18.

[67] 石智军, 姚克, 姚宁平, 等. 我国煤矿井下坑道钻探技术装备40年发展与展望[J]. 煤炭科学技术, 2020,48(04):1-34.

[68] 李杰. 定向高位长钻孔抽采位置确定及瓦斯治理效果[J]. 煤炭科学技术, 2014,42(12):51-53.

[69] 毕慧杰, 邓志刚, 赵善坤, 等. 高瓦斯综采工作面定向高位钻孔瓦斯抽采技术研究[J]. 煤炭科学技术, 2019,47(04):134-140.

[70] 林海飞, 杨二豪, 夏保庆, 等. 高瓦斯综采工作面定向钻孔代替尾巷抽采瓦斯技术[J]. 煤炭科学技术, 2020,48(01):136-143.

[71] 李彦明. 基于高位定向长钻孔的上隅角瓦斯治理研究[J]. 煤炭科学技术, 2018,46(01):215-218.

[72] Shouqing L, Yuanping C, Jinmin M, et al. Application of in-seam directional drilling technology for gas drainage with benefits to gas outburst control and greenhouse gas reductions in Daning coal mine, China[J]. Natural Hazards, 2014,73(3):1419-1437.

[73] 陈磊, 袁和勇, 薛韦一, 等. 高位钻孔与采空区埋管瓦斯抽放技术对比研究[J]. 中国安全生产科学技术, 2013,9(10):98-102.

[74] 于宝种. 上隅角不同插管深度瓦斯抽采效果研究[J]. 煤矿安全, 2017,48(07):169-172.

[75] 卢国斌, 郭宇箫, 田少波. 基于COMSOL的采空区瓦斯埋管抽采抽采口位置研究[J]. 辽宁工程技术大学学报, 2018,37(02):258-263.

[76] 康建宏, 邬锦华, 李绪明, 等. 采空区高抽巷及埋管抽采下瓦斯分布规律研究[J]. 采矿与安全工程学报, 2021,38(01):191-198.

[77] Li Y, Wu S, Nie B, et al. A new pattern of underground space‐time tridimensional gas drainage: A case study in Yuwu coal mine, China[J]. Energy Science & Engineering, 2019,7(2):399-410.

[78] Yao B, Ma Q, Wei J, et al. Effect of protective coal seam mining and gas extraction on gas transport in a coal seam[J]. International Journal of Mining Science and Technology, 2016,26(04):637-643.

[79] Wei P, Huang C, Li X, et al. Numerical simulation of boreholes for gas extraction and effective range of gas extraction in soft coal seams[J]. Energy Science & Engineering, 2019,7(5):1632-1648.

[80] 李晓红. 岩石力学实验模拟技术[M]. 科学出版社, 2007.

[81] 刘宏波. 综放工作面采空区自然发火三维数值模拟研究[D]. 中国矿业大学(北京), 2012.

[82] 王登科, 唐家豪, 魏建平, 等. 煤层瓦斯多机制流固耦合模型与瓦斯抽采数值模拟分析[J]. 煤炭学报, 2023,48(02):763-775.

[83] 陈月霞, 褚廷湘, 陈鹏, 等. 瓦斯抽采钻孔间距优化三维数值模拟量化研究[J]. 煤田地质与勘探, 2021,49(03):78-84.