矿井瓦斯事故是煤矿主要灾害之一，煤矿的安全生产长期以来一直受到此威胁，煤矿的经济效益也因此降低。目前瓦斯的治理工作主要还是依靠对煤层瓦斯的抽采，由于受抽采钻孔施工、封孔工艺、和客观地质条件等制约而影响了瓦斯的抽采效率。抽采钻孔周边的高渗区域裂隙严重降低了瓦斯抽采浓度和抽采效率，因此修复钻孔孔周裂隙并研究其修复规律，对科学合理防治瓦斯灾害具有一定指导意义。

通过对前人成果研究分析，提出新型膨胀粉体配比并开展粉体膨胀性、电镜扫描及流动性等测试，得到粉体自身特性。经过试件渗透性质对比，优选氧化钙类膨胀剂作为配比材料；实验表明填充材料本身具有良好的微膨胀性，其表现特征是反应初期膨胀速率较小，中期迅速增大最终趋于稳定，膨胀比随水固比增加而增大；填充材料通过表面微观结构观察，材料颗粒成独立存在，分布较为均匀，粒径分布处于1～10um之间，且颗粒间的粘合性较好；填充材料粉体流动性休止角整体差异不大，表明在一定粒径范围内，粉体粒径对其流动性并无较大影响，其流动性整体优于煤粉流动性。

随后开展裂隙填充实验，通过渗透率测定、超声波波幅波速前后对比，研究不同填充因素下，钻孔煤体内部裂隙的填充规律，得到在一定范围内，填充效果随填充风压增大而增大，膨胀粉体粒径过高或过低也不利于裂隙内部填充；填充实验完成后，试件超声波波幅增大，波速提高，表明内部裂隙修复具有一定效果。最后开展不同填充煤体与未填充煤体单轴压缩力学及声发射特征实验，研究对比膨胀粉体对煤体压缩破裂影响，得到未填充煤体总体破裂过程相较于填充煤体更为剧烈，能量和计数也都更为明显。

利用COMSOL建立模型对上部边界进行0.2～0.8MPa的流体压力加载，对煤岩体内部裂隙通道进行渗流运动的数值模拟分析，得到不同裂隙模型在不同压力状态下的流体渗流运动，在一定程度上表征了膨胀粉体在裂隙中的扩散状态。研究结果为探讨煤层裂隙填充规律、瓦斯抽采及防治煤与瓦斯安全事故方案的制定措施提供了一定理论依据。

Mine gas accident is one of the main disasters in coal mines. The safety production of coal mines has been threatened for a long time, and the economic benefits of coal mines have been reduced. At present, the gas control work mainly relies on the extraction of coal seam gas. Due to the constraints of drilling construction, sealing technology and objective geological conditions, the efficiency of gas extraction is affected. The cracks in the high permeability area around the extraction borehole seriously reduce the gas extraction concentration and extraction efficiency. Therefore, repairing the cracks around the borehole and studying its repair law have certain guiding significance for scientific and reasonable prevention and control of gas disasters.

Through the research and analysis of previous results, a new type of filling powder ratio was proposed and the powder expansion, electron microscope scanning and fluidity tests were carried out to obtain the characteristics of the powder itself. After comparing the permeability properties of the specimens, the calcium oxide expansion agent is preferred as the ratio material ; the experimental results show that the filling material itself has good micro-expansion, which is characterized by a small expansion rate in the early stage of the reaction, a rapid increase in the middle stage and finally tends to be stable, and the expansion ratio increases with the increase of water-solid ratio. The filler material is observed by the surface microstructure. The material particles are independent and evenly distributed. The particle size distribution is between 1 and 10 um, and the adhesion between the particles is good. The overall difference of the flow angle of repose of the filling material powder is not significant, indicating that within a certain particle size range, the powder particle size has no significant effect on its fluidity, and its fluidity is better than that of pulverized coal.

Then, the fracture filling experiment was carried out. Through the permeability measurement and the comparison of the ultrasonic amplitude and wave velocity before and after, the filling law of the internal fracture of the borehole coal body under different filling factors was studied. It was found that within a certain range, the filling effect increased with the increase of the filling wind pressure, and the particle size of the filling powder was too high or too low. After the filling experiment is completed, the ultrasonic amplitude of the specimen increases, the wave velocity increases, and the surface internal crack repair has a certain effect. Finally, the experiments of uniaxial compression mechanics and acoustic emission characteristics of different filled coals and unfilled coals were carried out to study and compare the influence of filling powder on coal compression fracture. It was found that the overall fracture process of unfilled coal was more severe than that of filled coal, and the energy and count were also more obvious.

The model is established by COMSOL to load the fluid pressure of 0.2 ~ 0.8 MPa on the upper boundary, and the numerical simulation analysis of the seepage movement of the fracture channel in the coal rock mass is carried out. The fluid seepage movement of different fracture models under different pressure states is obtained, which characterizes the diffusion state of the filled powder in the fracture to a certain extent. The research results provide a theoretical basis for discussing the filling law of coal seam cracks, gas extraction and the formulation of measures to prevent coal and gas safety accidents.

[1] 吴楠.中国煤炭产业发展现状分析[J]. 2019,No.649(23):64-65+67.

[2] 王双明.对我国煤炭主体能源地位与绿色开采的思考[J].中国煤炭,2020,46(2):11-16.

[3] 何祚庥.三论我国必须大幅度调整核政策——评《中国能源中长期(2030、2050)发展战略研究》“核能卷”中对我国铀资源的分析[J].今日国土,2011(07):23-27.

[4] 杨涛,赵星.我国近五年瓦斯爆炸事故发生规律与预防措施的探讨[J].华北科技学院学报,2016,13(01):19-23.

[5] 林海飞.综放开采覆岩裂隙演化与卸压瓦斯运移规律及工程应用[D].西安科技大学,2009.

[6] 王志璠.煤矿瓦斯抽采的必要性及抽采方法探讨[J].能源与节能,2018,No.152(05):187-188.

[7] 黄长国.深部松软煤层钻孔孔周煤体变形产渣特征研究[J].煤炭工程,2020,52(04):92-96.

[8] 黄鑫业,蒋承林本煤层瓦斯抽采钻孔带压封孔技术研究煤炭科学技术,2011,39(10):45-48.

[9] 梁运培,胡千庭,郭华,等.地面采空区瓦斯抽放钻孔稳定性分析[J].煤矿安全,2007,38(3):1-4.

[10] 肖福坤,刘刚,樊慧强,等.瓦斯抽采钻孔煤体破裂过程声发射特性试验研究[J].煤矿开采,2013,18(2):7-10.

[11] 肖福坤,张峰瑞,刘刚,等.固-气耦合作用下瓦斯抽采钻孔破裂规律研究[J].煤矿开采,2016,21(4):123-126,137.

[12] Wong T F. Micromechanics of faulting in westerly granite[J]. International Journal of Rock Mechanics &Mining Sciences &Geomechanics Abstracts, 1982,19(2):49-64.

[13] Lajtai E Z. BRITTLE FRACTURE IN COMPRESSION[J]. International Journal of Fracture, 1974,10(4):525-536.

[14] LAJTAI EZ,LAJTAIVN. The collapse of cavities [J]. International Journal of Rock Mechanics & Mining Sciences &Geomechanics Abstracts, 1975, 12(4): 81-86.

[15] Carter B J, Lajtai E Z, Petukhov A. Primary and remote fracture around underground cavities[J]. International Journal for Numerical & Analytical Methods in Geomechanics, 2010,15(1):21-40.

[16] Martin C D. Seventeenth canadian geotechnical colloquium: the effect of cohesion loss and stress path on brittle rock strength [J]. Can. Geotech. J. 1997,34(5):159-168

[17] 傅宇方,黄明利,任凤玉,等.不同围压条件下孔壁周边裂纹演化的数值模拟分析[J].岩石力学与工程学报,2000,19(5):577-583.

[18] 马少鹏,王来贵,赵永红.岩石圆孔结构破坏过程变形场演化的实验研究[J].岩土力学,2006,27(07):1082-1086.

[19] 姚向荣,程功林,石必明.深部围岩遇弱结构瓦斯抽采钻孔失稳分析与成孔方法[J].煤炭学报,2010,35(12):2073-2081.

[20] 张超,林柏泉,周延,等.本煤层近水平瓦斯抽采钻孔“强弱强”带压封孔技术研究[J].采矿与安全工程学报,2013,30(6):935-939.

[21] ZHANGChao,LIN Bai-quan, ZHOU Yan,et al. Study of “fracturing-sealing” integration technology based on high-energy gas fracturing in single seam with high gas content and low air permeability[J].International journal of mining science and technology,2013,23(6):841-846.

[22] 白以龙,夏蒙棼,柯孚久.固体损伤的演化诱致灾变和预测[J].失效分析与预防,2007,2(1):1-5.

[23] JIN Peijian, WANG Enyuan, LIU Xiaofei, et al. Damage evolution law of coalrock under uniaxial compression based on the electromagnetic radiation characteristics[J]. International Journal of Mining Science and Technology, 2013,23(2):221-227.

[24] 朱谭谭,靖洪文,苏海健,等.孔洞-裂隙组合型缺陷砂岩力学特性试验研究[J].煤炭学报,2015,40(7):1518-1525.

[25] 张天军,张磊,李树刚,等.含孔试样渐进性破坏的表面变形特征[J].煤炭学报,2017,42(10):2623-2630.

[26] 马少鹏,金观昌,潘一山.白光DSCM方法用于岩石变形观测的研究[J].实验力学,2002,17(1):10-16.

[27] 包林海,马少鹏,王建新.含转折非连通断层岩石破坏过程的试验研究[J].土木工程与管理学报,2011,28(4):58-60.

[28] 赵程,田加深,松田浩,等.单轴压缩下基于全局应变场分析的岩石裂纹扩展及其损伤演化特性研究[J].岩石力学与工程学报,2015,34(4):763-769.

[29] Tarokh A, Kao C S, Fakhimi A, et al. Insights on surface spalling of rock[J]. Computational Particle Mechanics, 2016,3(3):391-405.

[30] Eberhardt E,Stead D,Stimpson B,et al. Identifying crack initiation and propagation thresholds in brittle rock[J]. Canadian Geotechnical Journal,1998,35(2)：22-2233.

[31] 张晓平,王思敬,韩庚友,等.岩石单轴压缩条件下裂纹扩展试验研究——以片状岩石为例[J].岩石力学与工程学报,2011,30(9):1772-1781.

[32] 刘宁,张春生,褚卫江.锦屏深埋大理岩破裂特征与损伤演化规律[J].岩石力学与工程学报,2012,31(8):1606-1613.

[33] 周辉,孟凡震,张传庆,等.硬岩应力–应变门槛值特点及产生机制[J].岩石力学与工程学报,2015,34(08):1513-1521.

[34] 胡胜勇,刘红威.煤层瓦斯抽采钻孔漏气机理及应用研究进展[J].煤矿安全,2016,47(5):170-173.

[35] 周福宝,孙玉宁,李海鉴,等.煤层瓦斯抽采钻孔密封理论模型与工程技术研究[J].中国矿业大学学报,2016,45(3):433-439.

[36] 林井祥,孙广义.瓦斯抽采钻孔破坏过程数值分析[J].辽宁工程技术大学学报(自然科学版),2014,33(1):33-36.

[37] 王振锋,周英,孙玉宁,等.新型瓦斯抽采钻孔注浆封孔方法及封堵机理[J].煤炭学报,2015,40(3):588-595.

[38] 高亚斌.钻孔水射流冲击动力破煤岩增透机制及其应用研究[D].2016.

[39] 张峰瑞,肖福坤,申志亮,等.单轴压缩状态下瓦斯抽采钻孔破裂规律的实验研究[J].黑龙江科技大学学报,2016,26(1):17-20,30.

[40] 康向涛.煤层水力压裂裂缝扩展规律及瓦斯抽采钻孔优化研究[D].重庆:重庆大学,2014.

[41] 林柏泉,杨威,吴海进,等.影响割缝钻孔卸压效果因素的数值分析[J].中国矿业大学学报,2010,39(02):153-157.

[42] 周福宝,李金海,昃玺,等.煤层瓦斯抽放钻孔的二次封孔方法研究［J］.中国矿业大学学报,2009,38(6)：764-768.

[43] Zhou Fubao, Sun Yuning, LI Haijian, et al. Research on the theoretical model and engineering technology of the coal seam gas drainage hole sealing［J］.Journal of China University of Mining & Technology,2016,45(3):433-439.

[44] 任青山,艾德春,彭斌,等.自制膨胀材料在发耳煤矿瓦斯抽放钻孔封孔中的应用[J].煤炭技术,2014,33(07):07.098.

[45] 梁玉柱.固体颗粒二次封孔一体化技术的研究与应用[J].中国矿业,2020,29(05):142-148.

[46] 王志明,孙玉宁,宋维宾,等.瓦斯抽采二次膨胀封孔材料膨胀机理及应用研究[J].中国安全生产科学技术,2018,14(12):28-33.

[47] 孙文标,郭兵兵,张瑞林.高水材料型瓦斯预抽钻孔封孔材料膨胀应力的试验研究[J].煤炭技术,2022,41(05):82-85.

[48] Termkhajornkit P, Nawa T, Nakai M, et al. Effect of fly ash on autogenous shrinkage[J]. Cement & Concrete Research. 2005,35(3):473-482.

[49] Zhai C, Hao Z, Lin B. Research on a New Composite Sealing Material of Gas Drainage Borehole and Its Sealing Performance[J]. Procedia Engineering,2011,26:1406-1416.

[50] 刘健,唐田甜,卢婷,等.纳米氮化硅激活粉煤灰对矿用水泥封孔材料早强性能的影响[J].安全与环境学报,2020,20(05):1752-1757.

[51] Xiang X, Zhai C, Xu Y, et al. A flexible gel sealing material and a novel active sealing method for coal-bed methane drainage boreholes[J]. Journal of Natural Gas Science and Engineering,2015,26(3):1187-1199.

[52] Cheng J. ,Wang C. ,Zhang S. Methods to determine the minegas explosibility An overview [J]． Journal of Loss Prevention inthe Process Industries,2012,25(3):425－435.

[53] Cheng J. ,Zhang X. ,Ghosh A. Theoretical Explosion Ｒisk Assessment Model for Underground mine Atmosphere [J]． Journal of Fire Sciences,2017,35(1):21－35.

[54] Cheng J. ,Qi,C. ,Li S. Modeling Mine Gas Explosive Patternin Underground Mine Gob and Overlying Strata [J]．International Journal of Oil,Gas and Coal Technology,2019,22(4):554.

[55] 李思远,程健维.三维采空区及覆岩内瓦斯爆炸范围区间变化的模型试验研究[C]//第35届国际采矿岩层控制会议(中国):阜新,2016.

[56] 王兆丰,武炜.煤矿瓦斯抽采钻孔主要封孔方式剖析研究[J]．煤炭科学技术,2014(6):31-34,103.

[57] Price H S, McCulloch R C, Edwards J C, et al. Computer model study of methanemigration in coal beds[J]. Cim Bulletin,1973,66(737):103-112.

[58] 汤红枪,程健维,王文滨,等.瓦斯抽采钻孔非凝固恒压浆液封孔技术应用研究[J].煤炭工程,2019,51(02):45-48..

[59] 高振勇.二次注浆封孔技术对提高瓦斯抽采效率的应用研究[J].煤炭技术,2017,36(10):2017.10.056.

[60] 娄振,魏国营,张书进,等.煤层动态裂隙充填瓦斯抽采技术试验研究[J].中国安全科学学报,2016,26(10):127-132.

[61] 周福宝,孙玉宁,李海鉴,等.煤层瓦斯抽采钻孔密封理论模型与工程技术研究[J].中国矿业大学学报,2016,45(03):433-439.000498.

[62] 范育青,朱栋,汪华君,等.突出煤层瓦斯抽采钻孔封孔新技术研究与实践[J].煤矿开采,2013,18(05):99-103.2013.05.031.

[63] 马灵军,王宽,张云峰,等.瓦斯抽采钻孔化学注浆封孔技术的应用[J].煤矿安全,2011,42(07):100-102.2011.07.036.

[64] 娄振.煤层抽采钻孔周边裂隙填充堵漏机理及试验研究[D].中国矿业大学(北京),2021.

[65] 孙培德,万华根.煤层气越流固-气耦合模型及可视化模拟研究[J].岩石力学与工程学报,2004(07):1179-1185.

[66] 崔鹏飞.煤基注浆封孔材料对煤体堵漏降渗特性研究[D].河南理工大学,2019.

[67] 郝晋伟.瓦斯抽采钻孔密封性控制理论与技术研究[D].煤炭科学研究总院,2019.

[68] 高霞,李春雨,张保勇.型煤制备中成型压力和保压时间优选的实验研究[J].黑龙江科技大学学报,2021,31(02):197-202.

[69] 王登科,彭明,付启超,等.瓦斯抽采过程中的煤层透气性动态演化规律与数值模拟[J].岩石力学与工程学报,2016,35(04).

[70] 石海涛.瓦斯抽采钻孔稠化膨胀浆体封堵技术研究及应用[D].中国矿业大学,2017.

[71] 郑文忠,李瑞森,徐笠博,等.静态破碎技术研究综述与建议[J].哈尔滨工业大学学报,2021,53(05):190-200.

[72] 罗聪,陆海峰,郭晓镭,等.粉体流动性的静力学及动力学表征研究[J].化工新型材料,2020,48(10):186-191.

[73] 吴跃,申国鑫,杨磊,等.粒径对褐煤煤粉流动性影响研究[J].当代化工,2021,50(07):1572-1575+1697.

[74] 魏连雨,梁永广,马士宾,等.基于超声波的预应力波纹管注浆密实性与空洞部位检测技术[J].无损检测,2012,34(4):42-45.

[75] 吴顺涛.超声波在类岩石材料裂隙扩展过程中的传播特性及应用[D].中国矿业大学,2018.

[76] 林海飞,刘思博,李树刚,等.稳压条件下煤体稳定特性钻孔倾角效应的试验研究[J].采矿与安全工程学报,2021,38(03):575-583.

[77] 李存贵,徐守余.长期注水开发油藏的孔隙结构变化规律[J].石油勘探与开发.2003(02).

[78] 张天军,庞明坤,蒋兴科,等.负压对抽采钻孔孔周煤体瓦斯渗流特性的影响[J].岩土力学,2019,40(07):2517-2524.

[79] 程远平,董骏,李伟,等.负压对瓦斯抽采的作用机制及在瓦斯资源化利用中的应用[J].煤炭学报,2017,42(06):1466-1474.

[80] Wang H, Wang E, Li Z, et al. Study and application of dynamic inversion model of coal seam gas pressure with drilling[J]. Fuel,2020,280:118653.

[81] 赵刚.新型无机缓凝封孔材料封堵特性研究[D].中国矿业大学,2020.

[82] 王其虎.程潮铁矿裂隙岩体渗流预测模型及数值模拟研究[D].武汉科技大学,2012.

[83] 胡胜勇.瓦斯抽采钻孔周边煤岩渗流特性及粉体堵漏机理[D].中国矿业大学,2014

[84] 李治豪.煤岩受载下孔裂隙渗流特性研究[D].内蒙古科技大学,2021.