(1. China Coal Research Institute,Beijing 100013,China;2. Mine Safety Technology Branch,China Coal Research Institute,Beijing 100013,China;3. State Key Laboratory of Coal Mining and Clean Utilization,China Coal Research Institute,Beijing 100013,China)
Abstract:The key structure model is optimized in order to study the microseismic precursory characteristics of coal and gas outburst. Based on the optimized physical model of coal and gas outburst,a three-dimensional model with the mechanical properties of coal changing gradually in space is constructed by COMSOL Multiphysics. Firstly,the distribution and development of the original rock stress and the mining stress before and after the tunnel excavation are analyzed. Then the effects of ground stress,gas pressure and mechanical properties of coal on the acoustic emission in fracturing process of coal are analyzed. Finally,the development of microseismic signals before coal and gas outburst is analyzed according to the coal distribution,gas storage and the variation of the mining stress in the excavation process of tunnel around the dangerous area of coal and gas outburst. The places with the mechanical properties of coal changing drastically have areas of local high-stress,low-stress and large stress gradient. The peak stress in the high-stress area is located in the boundary surface of hard coal,while the stress valley in low-stress area is located in boundary surface of soft coal. In the tunneling process from the hard coal area to the boundary of soft coal area,the peak mining stress has experienced three stages:a normal period,a high value period and a low value period. The acoustic emission parameters of raw coal and briquette for outburst coal generally have a positive correlation with the loading stress during the failure process in conventional triaxial loading. Especially in the unstable development stage of the crack,the AE parameters increase rapidly and reach the maximum value. Besides,compared with the soft coal,hard coal has higher strength and acoustic emission intensity. Before the coal roadway tunneling meets the regional tectonic coal,the microseismic signals experienced three stages,a safe period,a foreshock period and a quiet period. And with the gradient of soft coal decreases gradually,the peak in the foreshock period decreases gradually,the quiet period increases gradually,the microseismic precursor of coal and gas outburst gradually becomes fuzzy,and the suddenness of coal and gas outburst is enhanced. However,before the uncovering of cross-cut coal,there is no quiet period,and the foreshock directly develops into the main shock.
朱南南1,2,3,张 浪2,3,舒龙勇2,3,范喜生2,3. 煤与瓦斯突出的微震前兆特性试验研究与预警案例分析[J]. 岩石力学与工程学报, 2018, 37(6): 1419-1429.
ZHU Nannan1,2,3,ZHANG Lang2,3,SHU Longyong2,3,FAN Xisheng2,3. Experimental study on microseismic precursory characteristics of coal and gas outburst and case analysis of early-warning. , 2018, 37(6): 1419-1429.
吴自立. AE信号参数预测预报煤(岩)与瓦斯突出危险性的进展及展望[J]. 矿业安全与环保,2005,32(1):27-29.(WU Zili. Progress and prospect of AE signal parameter for predicting coal and gas outburst hazard[J]. Ming Safety and Environmental Protection,2005,32(1):27-29.(in Chinese))
[8]
刘 超. 采动煤岩瓦斯动力灾害致灾机理及微震预警方法研究[博士学位论文][D]. 大连:大连理工大学,2011.(LIU Chao. Research on hazard mechanism and microseismic warning method for gas dynamic disasters of mining coal-rock[Ph. D. Thesis][D]. Dalian:Dalian University of Technology,2011.(in Chinese))
[9]
段 东,王辉跃,冯小静,等. 不同厚度软分层煤与瓦斯突出的微震前兆分布特征[J]. 煤矿安全,2011,42(9):9-11.(DUAN Dong,WANG Huiyue,FENG Xiaojing,et al. Microseism precursory characteristics of coal and gas outburst for contains different thickness of soft stratification[J]. Safety in Coal Mines,2011,42(9):9-11.(in Chinese))
[11]
舒龙勇,王 凯,齐庆新,等. 煤与瓦斯突出关键结构体致灾机制[J]. 岩石力学与工程学报,2017,36(2):347-356.(SHU Longyong,WANG Kai,QI Qingxin,et al. Key structural body theory of coal and gas outburst[J]. Chinese Journal of Rock Mechanics and Engineering,2017,36(2):347-356.(in Chinese))
[2]
尹光志,秦 虎,黄 滚. 不同应力路径下含瓦斯煤岩渗流特性与声发射特征实验研究[J]. 岩石力学与工程学报,2013,32(7):1 315-1 320.(YIN Guangzhi,QIN Hu,HUANG Gun. Experimental study of characteristics of seepage and acoustic emission of gas-filled coal under different stress paths[J]. Chinese Journal of Rock Mechanics and Engineering,2013,32(7):1 315-1 320.(in Chinese))
[12]
肖福坤,樊慧强,刘 刚,等. 三轴压缩下含瓦斯煤样破坏过程的声发射特性[J]. 黑龙江科技学院学报,2013,23(1):10-15.(XIAO Fukun,FAN Huiqiang,LIU Gang,et al. Study of acoustic emission characteristics of coal containing gas under triaxial compression[J]. Journal of Heilongjiang Institute of Science and Technology,2013,23(1):10-15.(in Chinese))
[6]
张伟民,周 勇,王珂奇. 声发射预测煤与瓦斯突出危险性方法及指标的研究[J]. 煤矿安全,1999,(5):2-4.(ZHANG Weimin,ZHOU Yong,WANG Keqi. Study of the method and index for prediction of coal and methane outburst hazard by acoustic emission[J]. Safety in Coal Mines,1999,(5):2-4.(in Chinese))
[3]
王恩元,何学秋,刘贞堂. 煤岩破裂声发射实验研究及R\S统计分析[J]. 煤炭学报,1999,24(3):48-51.(WANG Enyuan,HE Xueqiu,LIU Zhentang. Experimental research and R/S statistical analysis of AE during the fracture of coal or rock[J]. Journal of China Coal Society,1999,24(3):48-51.(in Chinese))
[4]
左建平,裴建良,刘建锋,等. 煤岩体破裂过程中声发射行为及时空演化机制[J]. 岩石力学与工程学报,2011,30(8):1 564-1 570. (ZUO Jianping,PEI Jianliang,LIU Jianfeng,et al. Investigation on acoustic emission behavior and its time-space evolution mechanism in failure process of coal-rock combined body[J]. Chinese Journal of Rock Mechanics and Engineering,2011,30(8):1 564-1 570.(in Chinese))
[5]
雷文杰,李绍泉,商 鹏,等. 微震响应煤与瓦斯突出模拟试验[J]. 采矿与安全工程学报,2014,31(1):161-166.(LEI Wenjie,LI Shaoquan,SHANG Peng,et al. Coal and gas outburst simulation experiment reacted by microseismic monitoring[J]. Journal of Mining and Safety Engineering,2014,31(1):161-166.(in Chinese))
[7]
王栓林. 煤与瓦斯突出危险性实时跟踪预测技术研究[硕士学位论文][D]. 西安:西安科技大学,2009.(WANG Shuanlin. Study on real-time trace techniques in risk predition of coal and gas outburst[M. S. Thesis][D]. Xi¢an:Xi¢an University of Science and Technology,2009.(in Chinese))
[10]
段 东. 煤与瓦斯突出影响因素及微震前兆分析[博士学位论文][D]. 沈阳:东北大学,2009.(DUAN Dong. Analysis of influencing factors of coal and gas outburst and microseism precusor[Ph. D. Thesis][D]. Shenyang:Northeastern University,2009.(in Chinese))
[13]
赵洪宝. 含瓦斯煤失稳破坏及声发射特性的理论与实验研究[博士学位论文][D]. 重庆:重庆大学,2009.(ZHAO Hongbao. Theoretical and experimental study on unstable failure and AE characteristic of coal contained gas[Ph. D. Thesis][D]. Chongqing:Chongqing University,2009.(in Chinese))
[14]
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.
[15]
刘 辉,陆菜平,窦林名,等. 微震法在煤与瓦斯突出监测与预报中的应用[J]. 煤矿安全,2012,43(4):82-85.(LIU Hui,LU Caiping,DOU Linming,et al. Application of microseismometry in coal and gas outburst monitoring and forecasting[J]. Safety in Coal Mines,2012,43(4):82-85.(in Chinese))