目前，我国煤矿工程中常采用长壁式采煤法中的综合机械化采煤工艺，该方法通过留设合理宽度的采区煤柱，以达到隔离采空区及保护开采影响下巷道安全的目的。由于在采区煤柱宽度优化过程中，缺乏对其受力变形破坏规律的系统性分析，容易产生片帮、垮帮、锚杆失效等一系列影响安全的矿山问题。因此，论文采用现场监测、理论分析、数值模拟相结合的方法，对柠条塔2^-2煤层采区煤柱受力变形破坏规律开展了研究，并选用合理的控制技术。论文主要研究内容如下：

在现场监测方面，选取柠条塔2^-2煤层S1231、S1202工作面的17.5m采区煤柱，通过收敛计测出表面位移、多点离层位移计测出深部位移、钻孔油枕应力计测出煤柱应力、以及深孔窥视仪测出深部破坏，并对两工作面监测结果进行结合对比分析。研究表明，采区煤柱在两次不同的采动影响下变形量都较小；第一次采动下煤柱塑性区宽度最大可能为1.5m，第二次采动对煤柱内部变形破坏影响更大，塑性区宽度发展为2m；第二次采动下煤柱内部1m处应力骤降，2m处应力增长迅速；煤柱内部破坏以纵向裂隙、相对错动、煤体产生碎块为主，为采区煤柱受力变形破坏规律研究提供现场支撑。

在理论分析方面，总结现场观测得到的柠条塔2^-2煤层S1231、S1202工作面的17.5m采区煤柱普遍存在片帮、纵向裂隙、垮帮等变形破坏特征，将其分为沿弱面或断层滑移破坏、剪切破坏、塑性流动破坏、竖向劈裂破坏四种破坏形式，同时分别从地质因素、开采因素、煤体自身力学性质概括了造成采区煤柱变形破坏的主要因素。其次，分析了其顶部荷载随时间的变化与应力的空间分布特征，并对不同极限荷载的煤柱所受上覆荷载与变形量关系进一步研究，得出煤柱的最理想工作状态及变形破坏机理，为塑性破坏区宽度计算提供帮助。

（3）在理论计算方面，建立弹塑性区力学分析模型，通过极限平衡理论求解煤柱采空区侧塑性区宽度为1.84m，另外采用弹塑性理论计算，并修正得煤柱巷道侧塑性区宽度为1.51m。利用弹性核理论计算法、荷载估算法、经验公式法三种常用方法得出该采区煤柱稳定的合理宽度需要大于11.35m。并对采区煤柱塑性区宽度计算中的影响参数进行全面分析，得到相应参数影响曲线及影响程度深浅。

（4）在数值模拟方面，采用FLAC^3D软件对柠条塔2^-2煤层进行建模，模拟出理论计算优化后11.35m采区煤柱，对其距离开采面0~50m内每隔10m处的水平应力、垂直应力、水平位移、塑性区变化进行分析研究，进一步得出11.35m采区煤柱的受力变形破坏规律及验证理论计算中的塑性区宽度，并为采区煤柱的控制技术奠定基础。

（5）在控制技术方面，根据采区煤柱开采下受力变形破坏规律，分析了其控制技术方法，选出了适合柠条塔2^-2煤层采区煤柱宽度优化为11.35m后的锚杆支护方案，再使用FLAC^3D软件模拟出加固之后采区煤柱的应力分布、变形特征、塑性区宽度，并与未加固前结果比较，得出该锚杆支护方案能有效控制采区煤柱的变形破坏的结论。

At present, the comprehensive mechanized coal mining technology in the long-wall coal mining method is often used in China 's coal mine engineering. This method achieves the purpose of isolating the goaf and protecting the safety of the roadway under the influence of mining by setting a reasonable width of the coal pillar in the mining area. Due to the lack of systematic analysis of its stress deformation and failure law in the process of coal pillar width optimization in mining area, it is easy to produce a series of mine problems affecting safety, such as spalling, collapse and anchor failure. Therefore, this paper uses the method of field monitoring, theoretical analysis and numerical simulation to study the deformation and failure law of coal pillar in 2^-2 coal seam mining area of Ningtiaota, and selects reasonable control technology. The main research contents are as follows:

(1)In terms of on-site monitoring, the coal pillars of 17.5 m mining area in S1231 and S1202 working faces of Ningtiaota 2^-2 coal seam were selected. The surface displacement was measured by convergence meter, the deep displacement was measured by multi-point separation displacement meter, the coal pillar stress was measured by drilling oil pillow stress meter, and the deep damage was measured by deep hole peeper. The research shows that the deformation of coal pillar in mining area is small under the influence of two different mining. The maximum width of the plastic zone of the coal pillar under the first mining may be 1.5 m, and the second mining has a greater impact on the internal deformation and failure of the coal pillar, and the width of the plastic zone develops to 2 m. Under the second mining, the stress at 1m inside the coal pillar drops sharply, and the stress at 2 m increases rapidly. The internal failure of coal pillars is dominated by longitudinal cracks, relative dislocation and coal fragments, which provides on-site support for the study of the deformation and failure law of coal pillars in mining areas.

(2)In the aspect of theoretical analysis, the deformation and failure characteristics of coal pillar in 17.5 m mining area of S1231 and S1202 working face of Ningtiaota 2^-2 coal seam obtained by field observation are summarized, such as spalling, longitudinal fracture and collapse. It is divided into four failure forms : slip failure along weak plane or fault, shear failure, plastic flow failure and vertical splitting failure. At the same time, the main factors causing the deformation and failure of coal pillar in mining area are summarized from geological factors, mining factors and mechanical properties of coal body. Secondly, the variation of the top load with time and the spatial distribution characteristics of the stress are analyzed, and the relationship between the overlying load and the deformation of the coal pillar with different ultimate loads is further studied. The optimal working state and deformation failure mechanism of the coal pillar are obtained, which provides help for the calculation of the width of the plastic failure zone.

(3)In the aspect of theoretical calculation, the mechanical analysis model of elastic-plastic zone is established. The width of plastic zone in coal pillar goaf is 1.84 m by limit equilibrium theory. In addition, the width of plastic zone in coal pillar roadway is 1.51 m by elastic-plastic theory. Using the three common methods of elastic core theory calculation method, load estimation method and empirical formula method, the reasonable width of coal pillar stability in this mining area needs to be greater than 11.35 m. The influence parameters in the calculation of plastic zone width of coal pillar in mining area are analyzed comprehensively, and the influence curve and influence degree of corresponding parameters are obtained.

(4)In the aspect of numerical simulation, FLAC^3D software is used to model the 2^-2 coal seam of Ningtiaota, and the coal pillar of 11.35 m mining area after theoretical calculation and optimization is simulated. The horizontal stress, vertical stress, horizontal displacement and plastic zone change at every 10 m within 0 ~ 50 m from the mining surface are analyzed and studied. The deformation and failure law of coal pillar in 11.35 m mining area and the width of plastic zone in theoretical calculation are further obtained, which lays a foundation for the control technology of coal pillar in mining area.

(5)In the aspect of control technology, according to the stress deformation and failure law of coal pillar mining in mining area, the control technology method is analyzed, and the bolt support scheme suitable for the coal pillar width of 2^-2 coal seam in Ningtiaota is optimized to 11.35 m. Then, FLAC^3D software is used to simulate the stress distribution, deformation characteristics and plastic zone width of coal pillar in mining area after reinforcement, and compared with the results before reinforcement, it is concluded that the bolt support scheme can effectively control the deformation and failure of coal pillar in mining area.

[1]袁亮. 我国煤炭主体能源安全高质量发展的理论技术思考[J]. 中国科学院院刊, 2023, 38(01):11-22.

[2]梁壮, 邸帅, 赵东波. 煤炭行业高质量发展存在的问题及对策研究[J]. 中国煤炭, 2022, 48(11):9-14.

[3]张宏, 郑旭鹤. 双碳愿景下煤炭行业低碳可持续发展模式研究[J]. 煤炭经济研究, 2022, 42(09):66-73.

[4]王树海. “双碳”背景下我国煤炭产业高质量发展建议[J]. 内蒙古煤炭经济, 2022(18):154-156.

[5]李慧, 张睿宁, 艾先能. 我国煤炭行业高质量发展现状、问题与对策[J]. 煤炭经济研究, 2022, 42(07):48-54.

[6]王慧, 杨天敏. 我国煤炭清洁高效利用现状及发展建议[J]. 能源,2023(03):64-69.

[7]康红普, 谢和平, 任世华, 等. 全球产业链与能源供应链重构背景下我国煤炭行业发展策略研究[J]. 中国工程科学, 2022, 24(06):26-37.

[8]魏慎洪, 白雪亮, 袁祥飞. 新形势下我国煤炭产业发展策略研究[J]. 中国煤炭, 2022, 48(12):16-21.

[9]杨敬轩, 刘长友, 杨宇, 等. 浅埋近距离煤层房柱采空区下顶板承载及房柱尺寸[J]. 中国矿业大学学报, 2013, 42(02):161-168.

[10]解兴智. 浅埋煤层房柱式采空区顶板-煤柱稳定性研究[J]. 煤炭科学技术, 2014, 42(07):1-4+9.

[11]于洋, 邓喀中, 范洪冬. 条带开采煤柱长期稳定性评价及煤柱设计方法[J]. 煤炭学报, 2017, 42(12):3089-3095.

[12]唐维军, 孙希奎, 王恒, 等. 膏体充填开采条带煤柱覆岩稳定效应研究[J]. 煤炭科学技术, 2017, 45(09):109-115.

[13]Wilson A H. An hypothesis concerning pillar stability[J]. The Mining Engineer, 1972, 131(1): 409-417.

[14]Reed G, Mctyer K, Frith R. An assessment of coal pillar system stability criteria based on a mechanistic evaluation of the interaction between coal pillars and the overburden[J]. International Journal of Mining Science and Technology, 2017, 27(1): 9-15.

[15]张海荣, 杨娟娟, 雷薪雍, 等. 盘区辅助回风巷护巷煤柱宽度尺寸研究[J]. 煤炭工程, 2022, 54(12):115-120.

[16]张拴才, 孙振于, 张玉亮, 等. 特厚煤层综放工作面防冲煤柱宽度优化[J]. 煤炭工程, 2020, 52(09):7-12.

[17]王铁牛. 采区防水煤柱留设合理性分析[J]. 煤矿安全, 2013, 44(06):193-195.

[18]丁长栋, 李志华, 张成辉. 许疃煤矿采区上山保护煤柱留设尺寸研究[J]. 煤炭技术, 2016, 35(11):90-92.

[19]刘金海, 郑学军, 刘虎, 等. 冲击地压矿井采区下山保护煤柱合理宽度研究[J]. 煤炭科学技术, 2021, 49(02):52-60.

[20]孙学军, 周莉. 基于FLAC数值模拟冲击地压矿井条带开采煤柱宽度研究[J]. 山东煤炭科技, 2016(07):1-3.

[21]柴银亮. 西曲矿浅埋硬顶大采高工作面煤柱宽度优化研究[J]. 山西冶金, 2019, 42(04):47-49.

[22]潘帅. 采区煤柱受采动影响应力及破坏规律数值模拟研究[J]. 煤矿现代化, 2020(01):94-96.

[23]窦林名, 田鑫元, 曹安业, 等. 我国煤矿冲击地压防治现状与难题[J]. 煤炭学报, 2022, 47(01):152-171.

[24]朱斯陶, 姜福兴, 刘金海, 等. 我国煤矿整体失稳型冲击地压类型、发生机理及防治[J]. 煤炭学报, 2020, 45(11):3667-3677.

[25]尉瑞, 杨文帅, 郭彦军, 等. 浅埋综放沿空小煤柱巷道矿压显现规律研究[J]. 煤炭科学技术, 2018, 46(S2):57-62.

[26]Singh R, Singh T N, Dhar B B. Coal pillar loading in shallow mining conditions[C]// International journal of rock mechanics and mining sciences & geomechanics abstracts. Pergamon, 1996, 33(8): 757-768.

[27]彭林军, 宋振骐, 周光华, 等. 大采高综放动压巷道窄煤柱沿空掘巷围岩控制[J]. 煤炭科学技术, 2021, 49(10):34-43.

[28]孟祥军, 赵鹏翔, 王绪友, 等. 倾斜厚煤层沿空掘巷窄煤柱留设尺寸及围岩控制技术研究[J]. 西安科技大学学报, 2022, 42(03):413-422.

[29]王志强, 武超, 罗健侨, 等. 特厚煤层巨厚顶板分层综采工作面区段煤柱失稳机理及控制[J]. 煤炭学报, 2021, 46(12):3756-3770.

[30]岳帅帅, 谢生荣, 陈冬冬, 等. 15 m特厚煤层综放高强度开采窄煤柱围岩控制研究[J]. 采矿与安全工程学报, 2017, 34(05):905-913.

[31]孙东飞, 尚奇. 深井6.8m大采高大断面沿空掘巷窄煤柱宽度及围岩控制研究[J]. 煤矿安全, 2022, 53(07):166-173.

[32]任建慧. 综放工作面过上覆集中煤柱矿压显现规律及控制技术研究[J]. 中国煤炭, 2022, 48(S1):248-257.

[33]刘建军, 张焦, 靖晓颖. 综放工作面护巷煤柱的留设研究与控制技术[J]. 中国矿业, 2022, 31(08):110-117.

[34]王金亮, 赵建光. 区段煤柱的载荷与变形时间相关性及其规律[J]. 煤矿开采, 2014, 19(03):33-35+89.

[35]王文博, 孙传平, 胡大冲. 采动效应下条带煤柱动态受力变形特征模拟研究[J]. 煤矿安全, 2018, 49(08):243-246.

[36]张艳丽. 采区煤柱中巷支承受力演化规律研究[J]. 现代矿业, 2012, 27(06):8-11.

[37]曹健, 黄庆享. 浅埋近距煤层煤柱集中应力传递规律分析[J]. 采矿与安全工程学报, 2021, 38(06):1071-1080.

[38]王智欣, 高林君, 周博, 等. 近距离煤层残留煤柱下回采巷道变形破坏研究[J]. 陕西煤炭, 2021, 40(04):36-39+58.

[39]Jayanthu S, Singh T N, Singh D P. Stress distribution during extraction of pillars in a thick coal seam[J]. Rock Mechanics and Rock Engineering, 2004, 37(3): 171.

[40]曹胜根, 曹洋, 姜海军. 块段式开采区段煤柱突变失稳机理研究[J]. 采矿与安程学报, 2014, 31(06):907-913.

[41]乔元栋, 孟召平, 朱帅, 等. 二次采动影响下区段煤柱破坏机制及围岩控制技术[J]. 煤炭科学技术, 2020, 48(06):71-77.

[42]张金亮, 王春雷, 闫帅. 王庄矿52采区区段煤柱稳定技术研究[J]. 能源技术与管理, 2009(05):62-65.

[43]邓广哲, 江万刚, 郝珠成. 基于统计损伤的综放区段煤柱变形时间相关性分析[J]. 采矿与安全工程学报, 2009, 26(04):413-417.

[44]周晓鹏, 张涛, 周超. 动力扰动下区段煤柱稳定机理和宽度设计研究[J]. 煤炭技术, 2019, 38(05):43-46.

[45]宋义敏, 杨小彬. 煤柱失稳破坏的变形场及能量演化试验研究[J]. 采矿与安全工程学报, 2013, 30(06):822-827.

[46]何耀宇, 宋选民, 赵金昌. 复杂受压条件下不同尺寸煤柱破坏倾向性研究[J]. 采矿与安全工程学报, 2015, 32(04):592-596.

[47]Jaiswal A, Shrivastva B K. Numerical simulation of coal pillar strength[J]. International Journal of Rock Mechanics and Mining Sciences, 2009, 46(4): 779-788.

[48]Hoek E, Brown E T. Empirical strength criterion for rock masses[J]. Journal of the geotechnical engineering division, 1980, 106(9): 1013-1035.

[49]潘黎明. 综采面采区煤柱矿压规律与合理宽度研究[J]. 煤炭技术, 2020, 39(05): 18-21.

[50]郭超, 秦洪岩, 张帆. 常村煤矿3号煤层采区煤柱稳定性模拟分析[J]. 煤炭与化工, 2019, 42(07):25-28.

[51]张广超, 何富连, 来永辉, 等. 高强度开采综放工作面采区煤柱合理宽度与控制技术[J]. 煤炭学报, 2016, 41(09):2188-2194.

[52]张开智, 韩承强, 李大勇, 等. 大小护巷煤柱巷道采动变形与小煤柱破坏演化规律[J]. 山东科技大学学报(自然科学版), 2006(04):6-9.

[53]赵宾, 王方田, 梁宁宁, 王文林. 高应力综放面区段煤柱合理宽度与控制技术[J]. 采矿与安全工程学报, 2018, 35(01):19-26.

[54]Salamon, MDG* & Munro A H. A study of the strength of coal pillars[J]. Journal of the Southern African Institute of Mining and Metallurgy, 1967, 68(2): 55-67.

[55]Bieniawski Z T. Strata control in mineral engineering[J]. 1986.

[56]张永杰, 柏建彪, 李磊, 等. 复合顶板松软煤层锚网喷支护实践[J]. 中国煤炭, 2010, 36(05):53-57.

[57]于贵良, 乔中栋. 大断面煤体硐室分部综掘及锚网喷支护施工技术[J]. 煤矿开采, 2006(04): 61-62.

[58]周徐. 芦岭矿巷道锚网喷支护技术的探索[J]. 煤炭科学技术, 2005(09); 23-24.

[59]张进鹏, 刘立民, 刘传孝, 等. 松软厚煤层异型切眼新型预应力锚注支护研究与应用[J]. 煤炭学报, 2021, 3(06): 1-12.

[60]Wang Fangtian, Zhang Cun, Wei Shuaifeng, et al. Whole section anchor grouting reinforcement technology and its application in underground roadways with loose andfractured surounding rock[J]. Tunnelling and Underground Space Technology. 2016, 51:133-143.

[61]Chen Jun, Zhao Chenhui, Ding Faxing, et al. Mechanical performance of the grouted lapped double reinforcements anchored in embedded corrugated sleev es[J] Structures, 2020, 28: 1354 -1365.

[62]苏超, 弓培林, 康红普, 等. 深井临空高应力巷道切顶卸压机理研究[J]. 采矿与安全工程学报, 2020, 37(06):1104-1113.

[63]郭忠华. 孤岛工作面巷道钻孔卸压机理及关键参数确定[J]. 太原理工大学学报, 2020, 51(06):906-911.

[64]林健, 郭凯, 孙志勇, 等. 强烈动压巷道水力压裂切顶卸压压裂时机研究[J]. 煤炭学报, 2021, 3(06): 1-9.

[65]Zhang Xingyu, Gao Yubing. Field experiment on directional roof presplitting for pressure relief of retained roadways[J]. Intenational Joumal of Rock Mechanics and Miningsciences, 2020, 134:434-436.

[66]Gao Rui, Yu Bin, Meng Xiangbin. Stress distribution and surounding rock control of mining near to the overlying coal pillar in the working face[J]. International Joumal ofMining Science and Technology, 2019, 29(6):881-887.

[67]王龙飞, 常泽超, 杨战标, 等. 深井近距离煤层群采空区下回采巷道联合支护技术[J]. 采矿与安全工程学报, 2018, 35(04):686-692.

[68]王志强, 苏越, 石磊, 等. 错层位外错式沿空掘巷机理及相邻巷道的立体化联合支护技术[J]. 煤炭学报, 2018, 43(S1):12-20.

[69]谢生荣, 郜明明, 陈冬冬, 等. 大巷穿采空区时锚网喷与组合框架联合支护技术[J]. 采矿与安全工程学报, 2017, 34(04):698-706.

[70]Peng Rui, Meng Xiangrui, Zhao Guangming, et al. Multi-echelon supp ort method to limit asymmetry instability in different lithology roadways under high ground stress[J]. Tunnelling and Underground Space Technology, 2021, 108: 103 111.

[71]牛滕冲, 王方田, 王文林, 等. 采区煤柱聚能失稳关键因素及控制技术[J/OL]. 采矿与岩层控制工程学报:1-11.

[72]Russell Frith, Guy Reed. Coal pillar design when considered a reinforcement problem rather than a suspension problem[J]. International Journal of Mining Science and Technology, 2018, 28(01):11-19.

[73]Jinlong Liu,Luwang Chen,Jili Wang. Mechanism of Reinforcement on Inwall of Coal Mine Shaft Wall[J]. Research journal of applied science, engineering and technology, 2013, 5(18):

[74]Yongshui Kang, Quansheng Liu, Guangqing Gong, et al. Application of a combined support system to the weak floor reinforcement in deep underground coal mine[J]. International Journal of Rock Mechanics and Mining Sciences, 2014, 71:

[75]Xinxian Zhai,Guangshuai Huang, Chengyu Chen,Rubo Li. Combined Supporting Technology with Bolt-Grouting and Floor Pressure-Relief for Deep Chamber: An Underground Coal Mine Case Study[J]. Energies, 2018, 11(1):

[76]Design consideration for reinforcement of coal mine roadways in the Illawarra coal measures[J]. International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1988, 25(2):

[77]Guangyi Sun, Xiao Luo. Numerical Simulation Analysis of Different Coal Mine Roadway Support Effect[J]. Advanced Materials Research, 2013, 2695(807-809):

[78]Xigui Zheng, Xiaowei Feng, Nong Zhang,et al. Serial decoupling of bolts in coal mine roadway supports[J]. Arabian Journal of Geosciences, 2015, 8(9):

[79]Renliang Shan, Yongsheng Bao, Shengchao Xiao, et al. Study on support Design of 2220 roadway in Majiliang Coal Mine based on FLAC3D[J]. IOP Conference Series: Earth and Environmental Science, 2021, 634(1):