Nonlinear evolution characteristics of acoustic emission and fracture mechanism of coal under gas pressure
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摘要: 研究含瓦斯煤岩的声发射演化特征对于揭示煤岩的变形破坏机制有着重要作用。利用渗流-应力耦合试验系统进行了含瓦斯煤岩三轴压缩试验,研究了瓦斯压力对声发射非线性演化特征的影响,并基于强度理论分析了瓦斯压力对煤岩强度的影响机制。结果表明：煤岩的声发射能量和体应变演化有较好的对应关系。随着瓦斯压力的减小,声发射能量快速增加阶段曲线变得更加陡峭,也表明煤岩的脆性破坏特性加强。声发射分形数呈现在峰值段之前下降,峰后又增长的趋势。峰前阶段,分维的降低表明煤岩内部微破裂的增多和主破裂的出现,煤岩内部损伤由无序随机分布逐渐向宏观有序破坏过渡。Abstract: The study on the evolution characteristics of acoustic emission of coal containing gas plays an important role in revealing the deformation and failure mechanism of coal.The triaxial compression tests on the coal containing gas is carried out by using the seepage stress coupling test system.The influence of gas pressure on the nonlinear evolution characteristics of acoustic emission of coal are studied, and the influence mechanism of gas pressure on coal strength is analyzed based on the strength theory.The results show that there is a good corresponding relationship between the acoustic emission energy and the volume strain evolution of coal.With the decrease of gas pressure, the acoustic emission energy increases rapidly, and the stage curve becomes more steep, which also indicates that the brittle failure characteristics of coal are strengthened.The fractal number of acoustic emission decreases before the peak and increases after the peak.At the pre-peak stage, the decrease of fractal dimension indicates the increase of micro-fracture and the appearance of main fracture in coal, and the internal damage of coal gradually transits from disordered random distribution to macro-ordered failure.
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Keywords:
- gas pressure /
- coal /
- impact tendency /
- acoustic emission /
- permeability
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图 1 煤岩声发射振铃计数-轴向应变演化曲线
Figure 1. Ring count-axial strain evolution curves of acoustic emission of coal
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图 3 不同瓦斯压力下煤岩的声发射关联维数
Figure 3. Acoustic emission correlation dimensions of coal under different gas pressures
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[1] 王振, 胡千庭, 文光才, 等. 采动应力场分布特征及其对煤岩瓦斯动力灾害的控制作用分析[J]. 煤炭学报, 2011, 36(4): 623-627. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201104022.htm WANG Zhen, HU Qian-ting, WEN Guang-cai, et al. Study on the distribution laws of mining pressure field and its control action on dynamic disasters in coal mines[J]. Journal of China Coal Society, 2011, 36(4): 623-627. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201104022.htm
[2] 丁百川. 中国煤矿主要灾害事故特点及防治对策[J]. 煤炭科学技术, 2017, 45(5): 109-114. https://www.cnki.com.cn/Article/CJFDTOTAL-MTKJ201705019.htm DING Baichuan. Characteristics and prevention measures of major disasters and accidents in China's coal mines[J]. Coal Science and Technology, 2017, 45(5): 109-114. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-MTKJ201705019.htm
[3] 秦虎, 黄滚, 蒋长宝, 等. 不同瓦斯压力下煤岩声发射特征试验研究[J]. 岩石力学与工程学报, 2013, 32(增刊2): 3719-3725. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2013S2092.htm QIN Hu, HUANG Gun, JIANG Changbao, etal. Experimentalresearchonacousticemission characteristics of coal and rock under different gas pressures[J]. Chinese Journal of Rock Mechanics and Engineering, 2013(S2): 3719-3725. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2013S2092.htm
[4] 丁鑫, 肖晓春, 吕祥锋, 等. 煤岩破裂过程声发射时-频信号特征与演化机制[J]. 煤炭学报, 2019, 44(10): 2999-3011. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201910007.htm DING Xin, XIAO Xiao-chun, LV Xiang-feng, et al. Characteristics and evolution mechanism of acoustic emission time-frequency signal during coal failure process[J]. Journal of China Coal Society, 2019, 44(10): 2999-3011. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201910007.htm
[5] 陈亮, 刘建锋, 王春萍, 等. 北山深部花岗岩不同应力状态下声发射特征研究[J]. 岩石力学与工程学报, 2012, 31(增刊2): 3618-3624. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2012S2025.htm CHEN Liang, LIU Jian-feng, WANG Chun-ping, etal. Studyofacousticemission characteristics of Beishan deep granite under different stress conditions[J]. Chinese Journal of Rock Mechanics and Engineering, 2012, 31(S2): 3618-3624. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2012S2025.htm
[6] 熊飞, 靖洪文, 苏海健, 等. 尖端相交裂隙砂岩强度与破裂演化特征试验研究[J]. 煤炭学报, 2017, 42(4): 886-895. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201704010.htm XIONG Fei, JING Hong-wen, SU Hai-jian, et al. Strength andfracturebehaviorsofsandstonesamplescontaining intersect fissures under uniaxial compression[J]. Journal of China Coal Society, 2017, 42(4): 886-895. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201704010.htm
[7] 李宏艳, 康立军, 徐子杰, 等. 不同冲击倾向煤体失稳破坏声发射先兆信息分析[J]. 煤炭学报, 2014, 39(2): 384-388. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201402028.htm LI Hong-yan, KANG Li-jun, XU Zi-jie, et al. Precursor information analysisonacousticemissionofcoalwith different outburst proneness[J]. Journal of China Coal Society, 2014, 39(2): 384-388. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201402028.htm
[8] SAILLARD M, MAYSTRE D. Scattering from random rough surfaces: a beam simulation method[J]. Journal of Optics, 1988, 19(4): 173-176.
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