MICRO-SEISMIC CHARACTERISTICS AND ITS CHANGE LAWS RESPONDED BY MINING EFFECTS
LEI Wenjie1，WANG Zhaofeng1，HAN Zhenli2，LENG Junfa3，RONG Tao1
(1. State key laboratory cultivation base for gas geology and gas control，Henan Polytechnic University，Henan，Jiaozuo 454000，China；2. Guizhou Institute of Coal Design and Research，Guizou Guiyang 245500，China；3. School of Mechanical and Power Engineering，Henan Polytechnic University，Henan，Jiaozuo 454000，China)
Abstract：According to the theory that the mining stress is the extrinsic impetus for coal and gas outburst，the micro-seismic monitoring system has been constructed to respond to the activities on the coal roadway mining. The process and its main causes of coal caving were analyzed，the characteristics responded by micro-seismic activities on the coal and its roof ruptures were studied. The monitoring system which is combined by sensors with three different levels of sensitivity is aimed to acquaint entirely the change law of mining stress emergence and development. Based on the selection of Wavelet basic function，the total signals which number is 396 activated by mining effects within half an hour were decomposed and reconstructed on the method of Wavelet packet into 4 layers based on the frequency sequence. The micro-seismic signals activated by mining were divided into four categories such as blasting，coal caving，roof and coal wall ruptures signals according to mining sequence and frequency band，and the change tendency of roof and coal wall ruptures events was analyzed on the normalized frequency energy. Coal caving and roof ruptures are caused by blasts；the roof pressure can lead to coal wall ruptures as well. Roof ruptures as well as coal wall ruptures represent the mining stress definitely. Roof pressure in the early stage responds tempestuously，which causes five sections of coal caving within 1.6 seconds after blasting，reached the peak after 1.933 seconds and stabilizes 24.89 minutes later；roof ruptures events are mainly concentrated in the early 2 minutes and its corresponding events rate is 76.2%. Comparatively，coal wall ruptures react with delay of 5.8 seconds relatively to roof pressure，reach the peak after 3.71 minutes and stabilizes 29.217 minutes later；coal wall ruptures events are mainly concentrated on the early 5 minutes and its corresponding events rate is 45.9%. Roof and coal wall ruptures events and the change tendency of its own normalized energy on the dominant frequency band disclose the process of transformation and adjustment of mining stress，and the result that the coal body itself can get stable or not responded by the mining effect can be used to predict and early warn the coal and gas outburst，which needs further thorough research.
[1] 胡千庭，赵旭生. 中国煤与瓦斯突出事故现状及其预防的对策建议[J]. 矿业安全与环保，2012，39(5)：1–7.(HU Qianting，ZHAO Xusheng. Present situation of coal and gas outburst accidents in China?s coal mines and countermeasures and suggestions for their prevention[J]. Mining Safety and Environmental Protection，2012，39(5)：1–7.(in Chinese))
[2] 雷文杰，李绍泉，商 鹏，等. 微震响应煤与瓦斯突出模拟试验[J]. 采矿与安全学报，2014，31(1)：161–166.(LEI Wenjie，LI Shaoquan，SHANG Peng，et al. Coal and gas outburst simulating experiment by micro-seismic monitoring[J]. Journal of Mining and Safety Engineering，2014，31(1)：161–166.(in Chinese))
[3] 鲜学福，辜 敏，李晓红，等. 煤与瓦斯突出的激发和发生条件[J]. 岩土力学，2009，30(3)：577–582.(XIAN Xuefu，GU Min，LI Xiaohong，et al. Excitation and occurrence conditions for coal and gas outburst[J]. Rock and soil mechanics，2009，V30(3)：577–582.(in Chinese))
[4] 周世宁，何学秋. 煤和瓦斯突出机制的流变假说[J]. 中国矿业大学学报，1990，19(2)：1–8.(ZHOU Shining，HE Xueqiu. Rheological hypothesis of coal and methane outburst mechanism[J]. Journal of China university of mining and technology，1990，19(2)：1–8.(in Chinese))
[5] 胡千庭，周世宁，周心权. 煤与瓦斯突出过程的力学机制[J]. 煤炭学报，2008，33(12)：1 368–1 372.(HU Qianting，ZHOU Shining，ZHOU Xinquan. Mechanical mechanism of coal and gas outburst process[J]. Journal of China Coal Society，2008，33(12)：1 368–1 372. (in Chinese))
[6] LU C P，DOU L M，LIU H，et al. Case study on microseismic effect of coal and gas outburst process[J]. International Journal of Rock Mechanics and Mining Sciences，2012，53：101–110.
[7] 王恩元，何学秋. 煤岩变形破裂电磁辐射的实验研究[J]. 地球物理学报，2000，43(1)：131–136.(WANG Enyuan，HE Xueqiu. An experimental study of the electromagnetic emission during the deformation and fracture of coal or rock[J]. Chinese Journal of Geophysics，2000，43(1)：131–136.(in Chinese))
[8] 许 江，周文杰，刘 东，等. 采动影响下突出煤体温度与声发射特性[J]. 煤炭学报，2013，38(2)：239–245.(XU Jiang，ZHOU Wenjie，LIU Dong，et al. Temperature and acoustic emission characteristics of coal in the process of outburst under the influence of mining[J]. Journal of China Coal Society，2013，38(2)：239–245.(in Chinese))
[9] 郭立稳，俞启香，蒋承林. 煤与瓦斯突出过程中温度变化的实验研究[J]. 岩石力学与工程学报，2000，19(3)：366–368.(GUO Liwen，YU Qixiang，JIANG Chenglin. Testing study on the variation of coal temperature during the process of coal and gas outburst[J]. Chinese Journal of Rock Mechanics，2000，19(3)：366–368.(in Chinese))
[10] 文光才，宁小亮，赵旭生. 矿井煤与瓦斯突出预警技术及其应用[J].煤炭科学技术，2011，39(2)：55–58.(WEN Guangcai，NING Xiaoliang，ZHAO Xusheng. Coal and gas outburst early warning technology and application in coal mine[J]. 煤炭科学技术，2011，39(2)：55–58.(in Chinese))
[11] 俞善炳. 恒稳推进的煤与瓦斯突出[J]. 力学学报，1988，20(2)：97–106.(YU Shanbing. Steady advance of coal and gas bursts[J]. Acta mechanical sinca，1988，20(2)：97–106.(in Chinese))
[12] 俞善炳，郑哲敏，谈庆明，等. 含气多孔介质的卸压破坏及突出的极强破坏准则[J]. 力学学报，1997，29(6)：641–646.(YU Shanbing，CHENG Chemin，TAN Qingming，et al. Damage of porous media containing pressurized gas by unloading and the maximum damage principle for critical outburst[J]. Acta mechanical sinca，1997，29(6)：641–646.(in Chinese))
[13] 蒋承林. 煤与瓦斯突出阵面的推进过程及力学条件分析[J]. 中国矿业大学学报，1994，23(4)：1–10.(JIANG Chenglin. Analysis on the developing process and mechanical conditions of coal and gas outburst front[J]. Journal of China university of mining and technology，1994，23(4)：1–10.(in Chinese))
[14] 冯夏庭，张传庆，陈炳瑞，等. 岩爆孕育过程的动态调控[J]. 岩石力学与工程学报，2012，31(10)：1 983–1 997.(FENG Xiating，ZHANG Chuangqing，CHEN Bingrui，et al. Dynamical control of rockburst evolution process[J]. Chinese Journal of Rock Mechanics and Engineering，2012，31(10)：1 983–1 997.(in Chinese))
[15] 陈炳瑞，冯夏庭，曾雄辉，等. 深埋隧道TBM掘进微震实时监测与特征分析[J]. 岩石力学与工程学报，2011，30(2)：275–283.(CHEN Bingrui，FENG Xiating，ZENG Xionghui，et al. Real-time microseismic monitoring and its characteristic analysis during TBM tunneling in deep-buried tunnel[J]. Chinese Journal of Rock Mechanics and Engineering，2011，30(2)：275–283.(in Chinese))
[16] CARMEN Capilla. Application of the Harr wavelet transform to detect microseismic signals arrivals[J]. Journal of applied geophysics，2006，59：36–46.
[17] RACHEL E.Learned，ALAN S. WILSKY. A wavelet packet approach to transient signal classification[J]. Applied and computational harmonic analysis，1995，265–278.
[18] 朱权洁，姜福兴，于正兴，等. 爆破震动与岩石破裂微震信号能量分布特征研究[J]. 岩石力学与工程学报，2012，31(4)：723–730.(ZHU Quanjie，JIANG Fuxing，YU Yongming，et al. Study on energy distribution characters about blasting vibration and rock fracture microseismic signal[J]. Chinese Journal of Rock Mechanics and Engineering，2012，31(4)：723–780.(in Chinese))
[19] 曾宇清，王卫东，贺启庸. 按频带顺序排列的小波包新算法及应用[J]. 力学学报，1998，30(2)：186–192.(ZENG Yuqing，WANG Weidong，HE Qiyong. Theory and application of new Wavelet packets algorithm with results in the order of frequency-bands[J]. ACTA Mechanica SINICA，1998，30(2)：186–192.(in Chinese))
[20] RONALD R. Coifman，Mladen Victor Wickerhauser. Entropy-based algorithms for best basis selection[J]. IEEE transactions on information Theory，1992，8(2)：713–718.
[21] 王恩元，何学秋，窦林名，等. 煤矿采掘过程中煤岩体电磁辐射特征及应用[J]. 地球物理学报，2005，48(1)：216–221(WANG Enyuan，HE Xueqiu，DOU Linming，et al. Electromagnetic radiation characteristics of coal and rocks during excavation in coal mine and their application[J]. Chinese Journal of Geophysics，2005，48(1)：216–222.(in Chinese))
2015, Vol. 34 
