Dynamic characteristics and crack propagation characteristics of gas-bearing coal under cyclic impact
WANG Lei1，WANG Ancheng1，CHEN Lipeng1，LI Shaobo1，LIU Huaiqian2
(1. State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mine，Anhui University of Science and Technology，Huainan，Anhui 232001，China；2. School of Energy and Mining Engineering，China University of Mining and Technology(Beijing)，Beijing 100083，China)
Abstract：In order to explore the cyclic impact dynamic characteristics and crack propagation law of coal under different initial gas pressures，the cyclic impact test of coal under different initial gas pressures is carried out by using the combined dynamic and dynamic loading test system of coal-rock containing gas，and the dynamic stress-strain curve of gas-bearing coal under cyclic impact load is obtained. The relationship between coal dynamic parameters and initial gas pressure under cyclic impact is analyzed，3D visualization and fine quantitative characterization of crack propagation process before and after cyclic impact of gas-bearing coal are realized by CT scanning technology. The results show that：(1) the dynamic stress-strain curves of gas-bearing coal under cyclic impact load are basically similar，which are divided into three stages：linear elastic stage，plastic stage and unloading stage. The dynamic parameters of coal under impact load decrease with the increase of the initial gas pressure，and the greater the initial gas pressure，the stronger the gas weakening erosion effect. (2) Based on the fracture slices extracted by CT scanning and the reconstructed 3D fracture results，it is shown that annular parallel cracks and axial splitting through cracks exist in the impinged coal. The crack propagation process can be effectively and quantitatively characterized by two-dimensional and three-dimensional fracture characteristic parameters of gas-bearing coal，and the characteristic parameters are proportional to the initial gas pressure. Under high gas pressure environment，the fracture network in coal body is more complex，the connectivity is higher，and the instability failure is more likely to occur. (3) Based on theoretical analysis，the causes of strength damage and deterioration of coal body are revealed from the perspective of gas erosion and internal stress wave propagation of coal body. Combined with the damage effect of gas and dynamic load on coal body，the causes of strapping failure of cyclic impact coal body under the action of gas are discussed. The research results are helpful to enrich the dynamic theory of gas-bearing coal and have a certain theoretical reference significance for the prevention and warning of coal and gas outburst disaster in mine.
[1] 谢和平. 深部岩体力学与开采理论研究进展[J]. 煤炭学报，2019，44(5)：1 283–1 305.(XIE Heping. Research review of the state key research development program of China：Deep rock mechanics and mining theory[J]. Journal of China Coal Society，2019，44(5)：1 283–1 305.(in Chinese))
[2] 谢和平，高 峰，鞠 杨. 深部岩体力学研究与探索[J]. 岩石力学与工程学报，2015，34(11)：2 161–2 178.(XIE Heping，GAO Feng，JU Yang. Research and development of rock mechanics in deep ground engineering[J]. Chinese Journal of Rock Mechanics and Engineering，2015，34(11)：2 161–2 178.(in Chinese))
[3] 李 铁，蔡美峰，王金安，等. 深部开采冲击地压与瓦斯的相关性探讨[J]. 煤炭学报，2005，30(5)：20–25.(LI Tie，CAI Meifeng，WANG Jin?an，et al. Discussion on relativity between rock burst and ga in deep exploitation[J]. Journal of China Coal Society，2005，30(5)：20–25.(in Chinese))
[4] 袁 亮. 低透高瓦斯煤层群安全开采关键技术研究[J]. 岩石力学与工程学报，2008，27(7)：1 370–1 379.(YUAN Liang. Key technique of safe mining in low permeability and methane-rich seam group[J]. Chinese Journal of Rock Mechanics and Engineering，2008，27(7)：1 370–1 379.(in Chinese))
[5] WANG L，WANG H，ZHU J T，et al. Experimental study on particle size distribution of impact crushed coal containing gas[J]. Fuel，2022， 325：124745.
[6] 袁 亮. 我国深部煤与瓦斯共采战略思考[J]. 煤炭学报，2016，41(1)：1–6.(YUAN Liang. Strategic thinking of simultaneous exploitation of coal and gas in deep mining[J]. Journal of China Coal Society，2016，41(1)：1–6.(in Chinese))
[7] 金解放，李夕兵，常军然，等. 循环冲击作用下岩石应力应变曲线及应力波特性[J]. 爆炸与冲击，2013，33(6)：613–619.(JIN Jiefang，LI Xibing，CHANG Junran，et al. Stress-strain curve and stress wave characteristics of rock subjected to cyclic impact loadings[J]. Explosion and Shock Waves，2013，33(6)：613–619.(in Chinese))
[8] 戴 兵，罗鑫尧，单启伟，等. 循环冲击荷载下含孔洞岩石损伤特性与能量耗散分析[J]. 中国安全科学学报，2020，30(7)：69–77.(DAI Bing，LUO Xinyao，SHAN Qiwei，et al. Analysis on damage characteristics and energy dissipation of rock with a single hole under cyclic impact loads[J]. China Safety Science Journal，2020，30(7)：69–77.(in Chinese))
[9] 赵洪宝，刘一洪，刘 瑞，等. 局部静载约束条件下动力扰动对煤岩损伤的影响[J]. 哈尔滨工业大学学报，2022，54(8)：80–89.(ZHAO Hongbao，LIU Yihong，LIU Rui，et al. Influence of dynamic disturbance on coal-rock damage under local static load constraints[J]. Journal of Harbin Institute of Technology，2022，54(8)：80–89.(in Chinese))
[10] 孔祥国，杨送瑞，王恩元，等. 冲击载荷瞬时扰动原煤试样破裂演化及瓦斯放散特征研究[J]. 岩石力学与工程学报，2023，42(6)：1 384–1 394.(KONG Xiangguo，YANG Songrui，WANG Enyuan，et al. Fracture evolution and gas emission characteristics of raw coal samples subjected to instantaneous disturbance of impact load[J]. Chinese Journal of Rock Mechanics and Engineering，2023，42(6)：1 384–1 394.(in Chinese))
[11] 王 磊，张 帅，刘怀谦，等. 冲击荷载下含瓦斯煤能量耗散及损伤破坏规律[J]. 岩土力学，2023，44(7)：1 901–1 915.(WANG Lei，ZHANG Shuai，LIU Huaiqian，et al. Research on energy dissipation and damage failure law of gas-bearing coal under impact loading [J]. Rock and Soil Mechanics，2023，44(7)：1 901–1 915.(in Chinese))
[12] 陈 亮，王恩元. 含瓦斯煤受载破坏瓦斯涌出的前兆特征研究[J]. 中国安全科学学报，2020，30(12)：79–84.(CHEN Liang，WANG Enyuan. Study on precursory characteristics of gas emission from damaged coal containing gas[J]. China Safety Science Journal，2020，30(12)：79–84. (in Chinese))
[13] 高保彬，王祖洸，李化敏，等. 瓦斯压力对煤样冲击倾向性的影响试验研究[J]. 煤炭学报，2018，43(增1)：140–148.(GAO Baobin，WANG Zuguang，LI Huamin，et al. Experimental study on the effect of outburst-proneness of coal by gas pressure[J]. Journal of China Coal Society，2018，43(Supp.1)：140–148.(in Chinese))
[14] 薛 熠，刘 嘉，梁 鑫，等. 瓦斯压力作用下煤岩的声发射非线性演化特征[J]. 岩土工程学报，2021，43(增1)：241–245.(XUE Yi，LIU Jia，LIANG Xin，et al. Nonlinear evolution characteristics of acoustic emission and fracture mechanism of coal under gas pressure[J]. Chinese Journal of Geotechnical Engineering，2021，43(Supp.1)：241–245.(in Chinese))
[15] 吴世跃，赵 文. 含吸附煤层气煤的有效应力分析[J]. 岩石力学与工程学报，2005，24(10)：1 674–1 678.(WU Shiyue，ZHAO Wen. Analysis of effective stress in adsorbed methane-coal system[J]. Chinese Journal of Rock Mechanics and Engineering，2005，24(10)：1 674–1 678.(in Chinese))
[16] 聂百胜，马延崑，何学秋，等. 煤与瓦斯突出微观机制探索研究[J]. 中国矿业大学学报，2022，51(2)：207–220.(NIE Baisheng，MA Yankun，HE Xueqiu，et al. Micro-scale mechanism of coal and gas outburst：A preliminary study[J]. Journal of China University of Mining and Technology，2022，51(2)：207–220.(in Chinese))
[17] 王汉鹏，张 冰，袁 亮，等. 吸附瓦斯含量对煤与瓦斯突出的影响与能量分析[J]. 岩石力学与工程学报，2017，36(10)：2 449–2 456. (WANG Hanpeng，ZHANG Bing，YUAN Liang，et al. Influence of adsorption gas content on coal and gas outburst and energy analysis[J]. Chinese Journal of Rock Mechanics and Engineering，2017，36(10)：2 449–2 456.(in Chinese))
[18] 王 磊，陈礼鹏，刘怀谦，等. 不同初始瓦斯压力下煤体动力学特性及其劣化特征[J]. 岩土力学，2023，44(1)：144–158.(WANG Lei，CHEN Lipeng，LIU Huaiqian，et al. Dynamic behaviors and deterioration characteristics of coal under different initial gas pressures[J]. Rock and Soil Mechanics，2023，44(1)：144–158.(in Chinese))
[19] 孔祥国，王恩元，李树刚，等. 震动载荷下含瓦斯煤动力学特征[J]. 煤炭学报，2020，45(3)：1 099–1 107.(KONG Xiangguo，WANG Enyuan，LI Shugang，et al. Dynamics characteristics of gas-bearing coal under shock load[J]. Journal of China Coal Society，2020，45(3)：1 099–1 107.(in Chinese))
[20] WANG G，QIN X J，SHEN J N，et al. Quantitative analysis of microscopic structure and gas seepage characteristics of low-rank coal based on CT three-dimensional reconstruction of CT images and fractal theory[J]. Fuel，2019，256：115900.
[21] 李兆霖，王连国，姜崇扬，等. 基于实时CT扫描的岩石真三轴条件下三维破裂演化规律[J]. 煤炭学报，2021，46(3)：937–949.(LI Zhaolin，WANG Lianguo，JIANG Chongyang，et al. Three-dimensional fracture evolution patterns of rocks under true triaxial conditions based on real-time CT scanning[J]. Journal of China Coal Society，2021，46(3)：937–949.(in Chinese))
[22] 黄慧琦，杨更社，叶万军，等. 基于CT-CA的天然裂隙岩石受拉破坏特性研究[J]. 工程地质学报，2022，30(5)：1 438–1 449.(HUANG Huiqi，YANG Gengshe，YE Wanjun，et al. Study on tensile failure characteristics of natural fractured rock based on CT-CA[J]. Journal of Engineering Geology，2022，30(5)：1 438–1 449.(in Chinese))
[23] 杨 琪，于岩斌，程卫民，等. 基于Micro-CT的受载煤岩裂隙孔隙时空演化规律[J]. 岩石力学与工程学报，2022，41(增1)：2 626–2 638.(YANG Qi，YU Yanbin，CHENG Weimin，et al. Micro-CT-based temporal and spatial evolution of fractures and pores in loaded coal[J]. Chinese Journal of Rock Mechanics and Engineering，2022，41(Supp.1)：2 626–2 638.(in Chinese))
[24] 李 静，刘 晨，刘惠民，等. 基于数字岩心的页岩储层岩石细观损伤机制研究[J]. 岩石力学与工程学报，2022，41(6)：1 103–1 113. (LI Jing，LIU Chen，LIU Huimin，et al. Study on meso-damage mechanism of shale reservoir rock based on digital cores[J]. Chinese Journal of Rock Mechanics and Engineering，2022，41(6)：1 103–1 113. (in Chinese))
[25] 董赟盛，郤保平，何水鑫，等. 石灰岩热冲击破裂二维分形参数演化规律研究[J]. 岩石力学与工程学报，2022，41(增 1)：2 823–2 833. (DONG Yunsheng，XI Baoping，HE Shuixin，et al. Study on evolution law of two-dimensional fractal parameters of thermal shock fracture of limestone[J]. Chinese Journal of Rock Mechanics and Engineering，2022，41(Supp.1)：2 823–2 833.(in Chinese))
[26] 张艳博，徐跃东，刘祥鑫，等. 基于CT的岩石三维裂隙定量表征及扩展演化细观研究[J]. 岩土力学，2021，42(10)：2 659–2 671. (ZHANG Yanbo，XU Yuedong，LIU Xiangxin，et al. Quantitative characterization and mesoscopic study of propagation and evolution of three-dimensional rock fractures based on CT[J]. Rock and Soil Mechanics，2021，42(10)：2 659–2 671.(in Chinese))
[27] 付 裕，陈 新，冯中亮. 基于CT扫描的煤岩裂隙特征及其对破坏形态的影响[J]. 煤炭学报，2020，45(2)：568–578.(FU Yu，CHEN Xin，FENG Zhongliang. Characteristics of coal-rock fractures based on CT scanning and its influence on failure modes[J]. Journal of China Coal Society，2020，45(2)：568–578.(in Chinese))
[28] 王登科，于 充，魏建平，等. 基于LBM方法的裂隙煤岩应力–应变过程中渗流特性研究[J]. 岩石力学与工程学报，2020，39(4)：695–704.(WANG Dengke，YU Chong，WEI Jianping，et al. Seepage characteristics of loaded fractured coal based on LBM Method[J]. Chinese Journal of Rock Mechanics and Engineering，2020，39(4)：695–704.(in Chinese))
[29] ZHOU Y X，XIA K，LI X B，et al. Suggested methods for determining the dynamic strength parameters and mode-i fracture toughness of rock materials[J]. International Journal of Rock Mechanics and Mining Sciences，2012，49：105–112.
[30] 李小双，尹光志，赵洪宝，等. 含瓦斯突出煤三轴压缩下力学性质试验研究[J]. 岩石力学与工程学报，2010，29(增1)：3 350–3 358. (LI Xiaoshuang，YIN Guangzhi，ZHAO Hongbao，et al. Experimental study of mechanical properties of outburst coal containing gas under triaxial compression[J]. Chinese Journal of Rock Mechanics and Engineering，2010，29(Supp.1)：3 350–3 358.(in Chinese))
[31] LIU H，WANG L，XIE G. Dynamic compression behavior of coal under different initial gas pressures[J]. Rock Mechanics and Rock Engineering，2023，(56)：2 213–2 228.
[32] YIN Z，CHEN W，HAO H，et al. Dynamic compressive test of gas-containing coal using a modified split Hopkinson pressure bar system[J]. Rock Mechanics and Rock Engineering，2020，53(2)：815–829.
[33] FENG J，WANG E，SHEN R，et al. Investigation on energy dissipation and its mechanism of coal under dynamic loads[J]. Geomechanics and Engineering，2016，11(5)：14.
[34] 焦振华，穆朝民，王 磊，等. 被动围压下煤冲击压缩动态力学特性试验研究[J]. 振动与冲击，2021，40(21)：185–193.(JIAO Zhenhua，MU Chaomin，WANG Lei，et al. Tests for dynamic mechanical properties of coal impact compression under passive confining pressure[J]. Journal of Vibration and Shock，2021，40(21)：185–193.(in Chinese))
[35] 李 明，茅献彪，曹丽丽，等. 高应变率下煤力学特性试验研究[J]. 采矿与安全工程学报，2015，32(2)：317–324.(LI Ming，MAO Xianbiao，CAO Lili，et al. Experimental study on mechanical properties of coal under high strain rate[J]. Journal of Mining and Safety Engineering，2015，32(2)：317–324.(in Chinese))
[36] 金解放，杨 益，廖占象，等. 动荷载与地应力对岩石响应特性的影响试验研究[J]. 岩石力学与工程学报，2021，40(10)：1 990–2 002. (JIN Jiefang，YANG Yi，LIAO Zhanxiang，et al. Effect of dynamic loads and geo-stresses on response characteristics of rocks[J]. Chinese Journal of Rock Mechanics and Engineering，2021，40(10)：1 990–2 002.(in Chinese))
[37] 宫凤强，李夕兵，刘希灵. 三维动静组合加载下岩石力学特性试验初探[J]. 岩石力学与工程学报，2011，30(6)：1 179–1 190.(GONG Fengqiang，LI Xibing，LIU Xiling. Preliminary experimental study of characteristics of rock subjected to 3d coupled static and dynamic loads[J]. Chinese Journal of Rock Mechanics and Engineering，2011，30(6)：1 179–1 190.(in Chinese))
[38] 彭瑞东，谢和平，鞠 杨. 二维数字图像分形维数的计算方法[J]. 中国矿业大学学报，2004，(1)：22–27.(PENG Ruidong，XIE Heping，JU Yang. Computation method of fractal dimension for 2D digital image[J]. Journal of China University of Mining and Technology，2004，(1)：22–27.(in Chinese))
[39] 腾俊洋，唐建新，王进博，等. 层状复合岩体损伤演化规律及分形特征[J]. 岩石力学与工程学报，2018，37(增1)：3 263–3 278.(TENG Junyang，TANG Jianxin，WANG Jinbo，et al. The evolution law of the damage of bedded composite rock and its fractal characteristics[J]. Chinese Journal of Rock Mechanics and Engineering，2018，37(Supp.1)：3 263–3 278.(in Chinese))
[40] 王登科，张 航，魏建平，等. 基于工业CT扫描的瓦斯压力影响下含瓦斯煤裂隙动态演化特征[J]. 煤炭学报，2021，46(11)：3 550– 3 564.(WANG Dengke，ZHANG Hang，WEI Jianping，et al. Dynamic evolution characteristics of fractures in gas?bearing coal under the influence of gas pressure using industrial CT scanning technology[J]. Journal of China Coal Society，2021，46(11)：3 550–3 564.(in Chinese))
[41] 王登科，吴 岩，魏建平，等. 基于灰度共生矩阵和工业CT扫描的受载含瓦斯煤裂隙动态演化特征[J]. 工程科学学报，2023，45(1)：31–43.(WANG Dengke，WU Yan，WEI Jianping，et al. Fracture dynamic evolution features of a coal-containing gas based on gray level co-occurrence matrix and industrial CT scanning[J]. Chinese Journal of Engineering，2023，45(1)：31–43.(in Chinese))
[42] 王守光，穆鹏宇，王嘉敏，等. CT扫描的煤岩面裂隙椭球模型重构与张量表征及其应用[J]. 煤炭学报，2022，47(7)：2 593–2 608. (WANG Shouguang，MU Pengyu，WANG Jiamin，et al. Ellipsoid reconstruction and tensor characterization of planar fractures in coal obtained by CT-scanning and the applications[J]. Journal of China Coal Society，2022，47(7)：2 593–2 608.(in Chinese))
[43] 朱昌星，孙家鑫，王彦伟. 基于CT扫描单轴压缩下注浆体试块裂隙动态演化过程试验研究[J]. 岩土力学，2022，43(9)：2 493–2 503. (ZHU Changxing，SUN Jiaxin，WANG Yanwei. Experimental study of fracture dynamic evolution process of grouting specimen under uniaxial compression based on CT scanning[J]. Rock and Soil Mechanics，2022，43(9)：2 493–2 503.(in Chinese))
[44] ZHU Q，WANG X，ZUO Y，et al. Numerical simulation of matrix swelling and its effects on fracture structure and permeability for a high-rank coal based on x-ray micro-ct image processing techniques[J]. Energy and Fuels，2020，34(9)：10 801–10 809.
[45] 唐一举，郝天轩，刘 静，等. 瓦斯与应力作用下煤体红外辐射响应研究[J]. 岩石力学与工程学报，2023，42(3)：594–605.(TANG Yiju，HAO Tianxuan，LIU Jing，et al. Infrared radiation response of coal under gas and stress[J]. Chinese Journal of Rock Mechanics and Engineering，2023，42(3)：594–605. (in Chinese))
[46] 徐晓萌. 含瓦斯煤冲击破坏特性及其瞬变电磁特征实验研究[博士学位论文][D]. 北京：中国矿业大学，2017.(XU Xiaomeng. Experimental investigation on the impact failure features and transient electromagnetic radiation characteristics of gas-bearing coal[Ph. D. Thesis][D]. Beijing：China University of Mining and Technology Press，2017.(in Chinese))
[47] 何学秋，王恩元，林海燕. 孔隙气体对煤体变形及蚀损作用机制[J]. 中国矿业大学学报，1996，(1)：6–11.(HE Xueqiu，WANG Enyuan，LIN Haiyan. Coal deformation and fracture mechanism under pore gas action[J]. Journal of China University of Mining and Technology，1996，(1)：6–11.(in Chinese))
[48] 姚宇平，周世宁. 含瓦斯煤的力学性质[J]. 中国矿业学院学报，1988，(1)：4–10.(YAO Yuping，ZHOU Shining. The mechanical property of coal containing gas[J]. Journal of China University of Mining and Technology，1988，(1)：4–10.(in Chinese))
[49] 聂百胜，何学秋，王恩元. 煤的表面自由能及应用探讨[J]. 太原理工大学学报，2000，(4)：346–348.(NIE Baisheng，HE Xueqiu，WANG Enyuan. Surface free energy of coal and its calculation[J]. Journal of Taiyuan University of Technology，2000，(4)：346–348.(in Chinese))
[50] 金解放，张雅晨，刘 康，等. 梯度应力对红砂岩应力波传播特性的影响研究[J]. 岩土力学，2023，44(4)：952–964.(JIN Jiefang，ZHANG Yachen，LIU Kang，et al. Effect of gradient stress on stress wave propagation characteristics of red sandstone[J]. Rock and Soil Mechanics，2023，44(4)：952–964.(in Chinese))
[51] 金解放，李夕兵，殷志强，等. 循环冲击下波阻抗定义岩石损伤变量的研究[J]. 岩土力学，2011，32(5)：1 385–1 393.(JIN Jiefang，LI Xibing，YIN Zhiqiang，et al. A method for defining rock damage variable by wave impedance under cyclic impact loadings[J]. Rock and Soil Mechanics，2011，32(5)：1 385–1 393.(in Chinese))
[52] 王 磊，陈礼鹏，刘怀谦，等. 不同初始瓦斯压力下煤体动力学特性及其劣化特征[J]. 岩土力学，2023，44(1)：144–158.(WANG Lei，CHEN Lipeng，LIU Huaiqian，et al. Dynamic behaviors and deterioration characteristics of coal under different initial gas pressures[J]. Rock and Soil Mechanics，2023，44(1)：144–158.(in Chinese))
[53] 张广辉，欧阳振华，李宏艳，等. 深部高瓦斯煤层冲击地压发生机制研究[J]. 煤矿安全，2016，47(6)：41–44.(ZHANG Guanghui，OUYANG Zhenhua，LI Hongyan，et al. Mechanism research on rock burst in deep coal seam with high gas[J]. Safety in Coal Mines，2016，47(6)：41–44.(in Chinese))
[54] 王 磊，刘怀谦，谢广祥，等. 含瓦斯煤孔裂隙结构精细表征及强度劣化机制[J]. 岩土力学，2021，42(12)：3 203–3 216.(WANG Lei，LIU Huaiqian，XIE Guangxiang，et al. Fine characterization of the pore and fracture structure and strength degradation mechanism of gas bearing coal[J]. Rock and Soil Mechanics，2021，42(12)：3 203–3 216.(in Chinese))
[55] 蒋 东，李永池，杨建民，等. 微孔洞有核长大损伤演化模型研究[J]. 应用力学学报，2018，35(2)：228–233.(JIANG Dong，LI Yongchi，YANG Jianmin，et al. Study on a nuclear grown up damage evolution model of micro voids[J]. Chinese Journal of Applied Mechanics，2018，35(2)：228–233.(in Chinese))
2023, Vol. 42 
