特厚煤层高强度综放回采覆岩裂隙发育受扰动影响明显，作为瓦斯运移通道，良好的裂隙发育、展布及演化特征在一定程度上有利于高瓦斯矿井工作面瓦斯高位抽采，这对于避免综放工作面上隅角瓦斯积聚具有重要意义。因此，本文以大佛寺煤矿40103综放工作面为研究基地，从掌握综放工作面覆岩裂隙发育演化规律，厘清瓦斯裂隙运移分布特征角度出发，通过经验理论计算、物理相似模拟、数值模拟分析及现场工程实践等技术方法开展研究，从而为相关矿井综放工作面回采过程中上隅角瓦斯超限难题提供数据基础及解决思路，论文主要取得以下研究成果：

（1）铺设了综放开采覆岩破断变形物理相似模型，揭示了综放开采覆岩变形破断特征。以特厚煤层综放工作面为研究对象，结合大佛寺煤矿40103工作面实际地质条件，从理论计算角度分析了覆岩裂隙发育高度，判别了覆岩关键层特征，在此基础上，根据相似模拟要求，铺设了综放开采覆岩运移物理模拟实验系统，分析了40103工作面不同推进距离下覆岩垮落形态及主要岩层垮落步距特征，掌握了覆岩“三带”发育特征，确定了覆岩各岩层层位沉降量，为数值计算模型校核提供了基础数据。

（2）建立了覆岩裂隙发育数值计算模型，掌握了综放开采覆岩裂隙发育演化规律。在获取覆岩主要沉降数据基础上，结合覆岩破断变形特征，通过调整覆岩主要岩层物理力学参数及节理参数，构建并校核了离散元数值计算模型，开展了特厚煤层综放工作面覆岩裂隙发育及闭合演化规律分析，掌握了工作面走向及倾向方向上覆岩裂隙发育形态特征，定量的分析了工作面不同推进距离下纵向贯通裂隙与横向离层裂隙分布状况，为裂隙场瓦斯运移提供了相关参数。

（3）构建了裂隙场瓦斯运移数值计算模型，厘清了覆岩裂隙场瓦斯运移规律。在掌握裂隙场分布特征情况下，构建了裂隙场瓦斯运移数值计算模型，分析了瓦斯在裂隙场内主要运移通道，同时将覆岩破断变形及裂隙发育演化研究所得出的走向带宽距、倾向带宽距及破断角等参数，代入采动裂隙场数值计算模型，采用高位定向钻孔+埋管抽采两种方式模拟抽采瓦斯，得到上隅角瓦斯浓度与现场实际工程应用效果一致，从而验证了本文的合理性。

The development of overlying rock fractures in high-strength fully mechanized caving mining of extra-thick coal seams is significantly affected by disturbances. As a gas migration channel, good fracture development, distribution, and evolution characteristics are conducive to high level gas extraction in high gas mine working faces, which is of great significance for avoiding gas accumulation in the upper corner of the fully mechanized top coal caving working face. Therefore, this article takes the 40103 fully mechanized top coal caving face of Dafosi Coal Mine as the research base. Starting from the perspective of mastering the development and evolution laws of overlying rock fractures in the fully mechanized top coal caving face and clarifying the distribution characteristics of gas fractures, the research is conducted through technical methods such as empirical theoretical calculation, physical similarity simulation, numerical simulation analysis, and on-site engineering practice, in order to provide a data basis and solutions for the problem of gas exceeding the limit in the upper corner during the mining process of the relevant fully mechanized top coal caving working face, the paper mainly achieves the following research results:

(1) A physical similarity model for the fracture and deformation of overlying rocks in fully mechanized top coal caving mining has been established, revealing the deformation and fracture characteristics of overlying rocks in fully mechanized top coal caving mining. Taking the fully mechanized top coal caving working face in extra-thick coal seams as the research object, combined with the actual geological conditions of the 40103 working face in Dafosi Coal Mine, the development height of overlying rock fractures was analyzed from a theoretical calculation perspective, and the key layer characteristics of overlying rock were identified. Based on this, the physical simulation experimental system for overlying rock migration in fully mechanized top coal caving mining was laid out according to similar simulation requirements. The caving morphology of overburden rock and the caving step characteristics of main strata under different advancing distances of 40103 working face are analyzed. The development characteristics of "three zones" of overburden rock are mastered, and the settlement of each stratum of overburden rock is determined, which provides basic data for the verification of numerical calculation model.

(2) The numerical calculation model of overburden fracture development is established, and the evolution law of overburden fracture development in fully mechanized caving mining is mastered. On the basis of obtaining the main settlement data of the overlying rock, combined with the characteristics of overlying rock fracture deformation, a discrete element numerical calculation model was constructed and verified by adjusting the physical and mechanical parameters and joint parameters of the main overlying rock layers. The development and closure evolution law of overlying rock fractures in the fully mechanized top coal caving working face of ultra-thick coal seams was analyzed, and the morphological characteristics of overlying rock fracture development in the strike and dip direction of the working face were mastered. Quantitative analysis was conducted on the distribution of longitudinal through fractures and transverse separation fractures under different advancing distances of the working face, providing relevant parameters for gas migration in the fracture field.

(3) The numerical calculation model of gas migration in fracture field is constructed, and the law of gas migration in overburden fracture field is clarified. Under the condition of mastering the distribution characteristics of the fracture field, the numerical calculation model of gas migration in the fracture field was constructed, and the main migration channels of gas in the fracture field were analyzed. At the same time, the parameters of strike bandwidth distance, dip bandwidth distance, and fracture angle obtained from the research on the fracture deformation and fracture development of overburden were substituted into the numerical calculation model of the mining fracture field. Two methods of high-level directional drilling and buried pipe extraction are used to simulate gas extraction. The gas concentration in the upper corner is consistent with the actual engineering application effect, which verifies the rationality of this paper.

[1] 袁亮, 王恩元, 马衍坤, 等. 我国煤岩动力灾害研究进展及面临的科技难题[J/OL]. 煤炭学报, 2023: 1-37

[2] 武强, 涂坤, 曾一凡. “双碳”目标愿景下我国能源战略形势若干问题思考[J]. 科学通报, 2023, 68(15): 1884-1898.

[3] 薛俊华, 肖健, 杜轩宏, 等. 我国煤矿保护层开采卸压瓦斯抽釆现状及发展趋势[J/OL]. 煤田地质与勘探, 2023: 1-13.

[4] 胡国忠, 李康, 许家林, 等. 覆岩采动裂隙空间形态反演方法及在瓦斯抽采中的应用[J]. 煤炭学报, 2023, 48(02): 750-762.

[5] 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.

[6] 袁亮. 我国煤层气开发利用的科学思考与对策[J]. 科技导报, 2011, 29(22): 3.

[7] 王家臣. 我国综放开采40年及展望[J]. 煤炭学报, 2023, 48(01): 83-99.

[8] 许家林, 钱鸣高, 金宏伟. 基于岩层移动的“煤与煤层气共采”技术研究[J]. 煤炭学报, 2004(02): 129-132.

[9] 钱鸣高, 缪协兴, 何富连. 采场“砌体梁”结构的关键块分析[J]. 煤炭学报, 1994(06): 557-563.

[10] 钱鸣高, 李鸿昌. 采场上覆岩层活动规律及其对矿山压力的影响[J]. 煤炭学报, 1982(02): 1-12.

[11] 钱鸣高, 赵国景. 老顶断裂前后的矿山压力变化[J]. 中国矿业学院学报, 1986(04): 14-22.

[12] 宋振骐, 郝建, 石永奎, 等. “实用矿山压力控制理论”的内涵及发展综述[J]. 山东科技大学学报(自然科学版), 2019, 38(01): 1-15.

[13] Karmis M, Triplett T, Haycocks C, et al. Mining Subsidence and its Prediction in the Appalachian Coalfield [J]. U.s.symposium on Rock Mechanics, 1983.

[14] Hasenfus GJ, Johnson KL, Su DWH. A hydro geomechanical study of overburden aquifer response to longwall mining. Proceedings, 7th Conf. Ground Control in Mining, 3-5 August 1988, Morgantown. West Virginia University, Morgantown: 144-152.

[15] Bai M, Elsworth D. Some aspects of mining under aquifers in China [J]. Mining Science & Technology, 1990, 10(1): 81-91.

[16] Palchik V. Influence of physical characteristics of weak rock mass on height of caved zone over abandoned subsurface coal mines [J]. Environmental Geology, 2002, 42(1): 92-101.

[17] 刘天泉. 矿山岩体采动影响与控制工程学及其应用[J]. 煤炭学报, 1995(01): 1-5.

[18] Hu G, Xu J, Zhang F, et al. Coal and Coalbed Methane Co-Extraction Technology Based on the Ground Movement in the Yangquan Coalfield, China [J]. Energies, 2015, 8(7): 6881-6897.

[19] 钱鸣高, 缪协兴, 许家林. 岩层控制中的关键层理论研究[J]. 煤炭学报, 1996(03): 2-7

[20] 茅献彪, 缪协兴, 钱鸣高. 采动覆岩中关键层的破断规律研究[J]. 中国矿业大学学报, 1998(01): 41-44.

[21] 黄庆享. 厚沙土层在顶板关键层上的载荷传递因子研究[J]. 岩土工程学报, 2005(06): 672-676.

[22] 蒋先统. 浅埋复合关键层工作面底抽巷布置研究[J]. 煤炭技术, 2017, 36(12): 53-56.

[23] Chai J, Ma Z, Zhang D, et al. Experimental study on PPP-BOTDA distributed measurement and analysis of mining overburden key movement characteristics [J].Optical Fiber Technology, 2020, 56: 102175.

[24] Xiaojun F, Enyuan W, Rongxi S, et al. The dynamic impact of rock burst induced by the fracture of the thick and hard key stratum [J]. Procedia Engineering, 2011, 26: 457-465.

[25] 赵毅鑫, 令春伟, 刘斌, 等. 浅埋超大采高工作面覆岩裂隙演化及能量耗散规律研究[J]. 采矿与安全工程学报, 2021, 38(01): 9-18+30.

[26] 崔峰, 贾冲, 来兴平, 陈建强. 近距离强冲击倾向性煤层上行开采覆岩结构演化特征及其稳定性研究[J]. 岩石力学与工程学报, 2020, 39(03): 507-521.

[27] 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(5): 20-23.

[28] 李树刚. 综放开采围岩活动影响下瓦斯运移规律及其控制[J]. 岩石力学与工程学报, 2000(6): 809-810.

[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(Z1): 44-46.

[30] 杨科, 谢广祥. 应力壳与采动裂隙演化特征及其动态效应[C/OL]. 中国煤炭学会, 2010: 231-242.

[31] 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.

[32] 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(2): 298-303.

[33] 林海飞, 李树刚, 成连华, 等. 覆岩采动裂隙演化形态的相似材料模拟实验[J]. 西安科技大学学报, 2010, 30(5): 507-512.

[34] 林建成, 郭林生, 李可, 等. 覆岩采动裂隙演化规律相似材料模拟试验[J]. 陕西煤炭, 2021, 40(2): 14-18.

[35] 肖鹏, 李树刚, 林海飞, 等. 基于物理相似模拟实验的覆岩采动裂隙演化规律研究[J]. 中国安全生产科学技术, 2014, 10(4): 18-23.

[36] 赵兵朝, 余学义. 导水裂缝带的广义损伤因子研究[J]. 中国矿业大学学报, 2010, 39(5): 705-708.

[37] 赵兵朝, 刘樟荣, 同超, 等. 覆岩导水裂缝带高度与开采参数的关系研究[J]. 采矿与安全工程学报, 2015, 32(4): 634-638.

[38] 李振华, 丁鑫品, 程志恒. 薄基岩煤层覆岩裂隙演化的分形特征研究[J]. 采矿与安全工程学报, 2010, 27(4): 576-580.

[39] 李宏艳, 王维华, 齐庆新, 等. 基于分形理论的采动裂隙时空演化规律研究[J]. 煤炭学报, 2014, 39(6): 1023-1030.

[40] Cui F, Jia C, Lai X, et al. Study on the law of fracture evolution under repeated mining of close-distance coal seams [J]. Energies, 2020, 13(22): 6064.

[41] Ye Q, Wang G, Jia Z, et al. Similarity simulation of mining-crack-evolution characteristics of overburden strata in deep coal mining with large dip [J]. Journal of Petroleum Science and Engineering, 2018, 165: 477-487.

[42] Zhu T, Li W, Wang Q, et al. Study on the height of the mining-induced water-conducting fracture zone under the q2l loess cover of the jurassic coal seam in northern shaanxi, china [J]. Mine Water and the Environment, 2020, 39(1): 57-67.

[43] Sun B, Zhang P, Wu R, et al. Research on the overburden deformation and migration law in deep and extra-thick coal seam mining [J]. Journal of Applied Geophysics, 2021, 190: 104337.

[44] He C, Lu W, Zha W, et al. A geomechanical method for predicting the height of a water-flowing fractured zone in a layered overburden of longwall coal mining [J]. International Journal of Rock Mechanics and Mining Sciences, 2021, 143: 104798.

[45] Tang J, Zhang X, Sun S, et al. Evolution characteristics of precursor information of coal and gas outburst in deep rock cross-cut coal uncovering [J]. International Journal of Coal Science & Technology, 2022, 9(1): 5.

[46] Xie Z, Zhang N, Feng X, et al. Investigation on the evolution and control of surrounding rock fracture under different supporting conditions in deep roadway during excavation period [J]. International Journal of Rock Mechanics and Mining Sciences, 2019, 123: 104122.

[47] Liu J, Wang R, Lei G, et al. Studies of stress and displacement distribution and the evolution law during rock failure process based on acoustic emission and microseismic monitoring [J]. International Journal of Rock Mechanics and Mining Sciences, 2020, 132: 104384.

[48] Shukla N, Mishra M K. Assessment of crack stress thresholds and development of a pre-failure indicator using digital image correlation approach for coal specimen [J]. Geomechanics and Geophysics for Geo-Energy and Geo-Resources, 2021, 7(4): 103.

[49] 柴敬, 杜文刚, 张丁丁, 等. 基于BOTDA技术感测的大倾角煤层顶板活动规律研究[J]. 岩石力学与工程学报, 2019, 38(9): 1809-1818.

[50] 来兴平, 张旭东, 单鹏飞, 等. 厚松散层下三软煤层开采覆岩导水裂隙发育规律[J]. 岩石力学与工程学报, 2021, 40(9): 1739-1750.

[51] Wang L, Cheng Y, Li F, et al. Fracture evolution and pressure relief gas drainage from distant protected coal seams under an extremely thick key stratum [J]. Journal of China University of Mining and Technology, 2008, 18(2): 182-186.

[52] 周世宁, 孙辑正. 煤层瓦斯流动理论及其应用[J]. 煤炭学报, 1965(1): 24-37.

[53] 谭学术, 鲜学福, 张广洋, 等. 煤的渗透性研究[J]. 西安矿业学院学报, 1994(1): 22-25+21.

[54] Sun Peide.Coal gas dynamics and its applications [J]. Scientia Geologica Sinica, 1994,3(1): 66-72.

[55] Sun Peide. Study on the mechanism of interaction for coal and methane gas [J]. Journal of Coal Science & Engineering (China), 2001(01): 58-63.

[56] 黄运飞, 孙广忠, 姚宝魁. 煤-瓦斯介质力学概论[C/OL]. 中国地质学会工程地质专业委员会, 1992: 233-239.

[57] 孙培德. 煤层瓦斯流场流动规律的研究[J]. 煤炭学报, 1987(4): 74-82.

[58] 罗新荣. 煤层瓦斯运移物理模拟与理论分析[J]. 中国矿业大学学报, 1991(3): 58-64.

[59] 杨其銮, 王佑安. 煤屑瓦斯扩散理论及其应用[J]. 煤炭学报, 1986(3): 87-94.

[60] 段三明, 聂百胜. 煤层瓦斯扩散-渗流规律的初步研究[J]. 太原理工大学学报, 1998(4): 84-87+92.

[61] 李树刚, 张伟, 邹银先, 等. 综放采空区瓦斯渗流规律数值模拟研究[J]. 矿业安全与环保, 2008(2): 1-3+7+91.

[62] 金龙哲, 姚伟, 张君. 采空区瓦斯渗流规律的CFD模拟[J]. 煤炭学报, 2010, 35(9): 1476-1480.

[63] 滕桂荣, 谭云亮, 高明. 基于lattice Boltzmann方法对裂隙煤体中瓦斯运移规律的模拟研究[J]. 岩石力学与工程学报, 2007(S1): 3503-3508.

[64] 丁厚成. U+L型通风采空区瓦斯运移数值模拟与实验研究[J]. 自然灾害学报, 2012, 21(6): 192-198.

[65] Khodot V V. Role of methane in the stress state of a coal seam [J]. Soviet Mining Science, 1980, 16(5): 460-466.

[66] Zhang K, Wang L, Cheng Y, et al. Geological control of fold structure on gas occurrence and its implication for coalbed gas outburst: case study in the qinan coal mine, huaibei coalfield, china [J]. Natural Resources Research, 2020, 29(2): 1375-1395.

[67] 秦玉金, 罗海珠, 姜文忠, 等. 非等温吸附变形条件下瓦斯运移多场耦合模型研究[J]. 煤炭学报, 2011, 36(3): 412-416.

[68] 许江, 彭守建, 尹光志, 等. 含瓦斯煤热流固耦合三轴伺服渗流装置的研制及应用[J]. 岩石力学与工程学报, 2010, 29(5): 907-914.

[69] Zhao Y, Lin B, Liu T. Thermo-hydro-mechanical couplings controlling gas migration in heterogeneous and elastically-deformed coal [J]. Computers and Geotechnics, 2020, 123: 103570.

[70] Fan C, Wen H, Li S, et al. Coal seam gas extraction by integrated drillings and punchings from the floor roadway considering hydraulic-mechanical coupling effect [J]. Geofluids, 2022, 2022: 5198227.

[71] Hu S, Liu X, Li X. Fluid–solid coupling model and simulation of gas-bearing coal for energy security and sustainability [J]. Processes, 2020, 8(2): 254.

[72] 赵晶, 皮希宇, 王栓林, 等. 高瓦斯薄煤层采煤工作面高位钻孔瓦斯抽采技术[J]. 煤炭科学技术, 2015, 43(11): 78-82.

[73] 仵鹏飞. 高位定向长钻孔在综放工作面顶板裂隙瓦斯抽采中的应用研究[J]. 山西化工, 2023, 43(04): 135-136+142.

[74] 吴建俊. 水力压裂增透在低透气性煤层瓦斯抽采中的应用[J]. 煤, 2023, 32(05): 103-105.

[75] 任奇祥, 宋勇, 王建. 高瓦斯矿井本煤层定向钻孔瓦斯抽采技术应用[J]. 能源技术与管理, 2023, 48(02): 26-27.

[76] 徐经苍, 南晶晶, 刘斌, 杨永良. 瓦斯抽采影响因素及布孔参数优化模拟研究[J]. 煤炭科技, 2023, 44(02): 74-80.

[77] 王春光. 上覆岩层冒落带和裂隙带高度的确定[J]. 露天采矿技术, 2013(03): 30-32+35.

[78] 弓培林. 大采高采场围岩控制理论及应用研究[D]. 太原理工大学, 2006.

[79] 蔡志炯. 大采高直接顶关键层结构转化特征研究[J]. 煤矿安全, 2016,47(09): 56-59.

[80] 于斌, 朱卫兵, 高瑞, 刘锦荣. 特厚煤层综放开采大空间采场覆岩结构及作用机制[J]. 煤报, 2016, 41(03): 571-580.