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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土工测试专业委员会自成立以来，开展了一系列的学术研讨活动，迄今已举办30届全国土工测试学术研讨会。进入21世纪以来，因气候变化和全球变暖导致极端气候事件增多，暴雨、滑坡、泥石流等自然灾害频发，给岩土工程建设和土工测试技术带来了前所未有的挑战，在对环境保护、可持续发展和数字经济越来越重视的趋势下，工程建设需要更加精准地评估岩土参数，对土工测试技术的发展提出了更高要求。
土工测试技术的发展不仅能够促进岩土工程设计的优化，也能够推动岩土工程理论的创新。为促进相互交流学习，第30届全国土工测试学术研讨会围绕土的基本性质测试、土工物理模型测试、土工原位测试、现场土工监测、环境土工测试、特殊土测试等方面进行了广泛的学术交流。
第30届全国土工测试学术研讨会于2023年8月18—20日在北京召开，会议由中国土木工程学会土力学及岩土工程分会和中国水利学会岩土力学专业委员会共同主办，中国水利水电科学研究院、南京水利科学研究院、长江科学院等14家单位承办。会议筹办期间共收到110篇学术论文，经审稿委员会审议向《岩土工程学报》（增刊）荐论文56篇。同时，本届研讨会举办了细粒土三轴压缩平行试验，共收到19家单位的试验成果。本次会议以“探索•创新”为主题，会议设主会场1个，分会场4个，参会报名约60家单位，共组织特邀报告24个、主题报告64个。论文和报告涉及内容丰富，既有对学科基础理论的深入探讨，又有针对工程实践的案例分析和经验总结，这种跨学科的研讨有力地推动了土工测试领域的发展。
感谢对本届会议的召开鼎力相助的中国水利水电科学研究院及各有关单位，感谢向本届会议投稿并对因疫情而延期表示理解的各位专家和同行，感谢审稿专家对本次会议审稿工作的辛勤付出。尤其是《岩土工程学报》编辑部，为使本届会议的论文集面世，做了大量工作，专门编辑出版了本期增刊，特此表示感谢。
第30届全国土工测试学术研讨会组委会 -
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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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