Experimental study on microseismic precursory characteristics of coal and gas outburst and case analysis of early-warning

被引：0
|
作者：
Zhu N. [1 ,2 ,3 ]
Zhang L. [1 ,2 ,3 ]
Shu L. [1 ,2 ,3 ]
Fan X. [1 ,2 ,3 ]
机构：
[1] China Coal Research Institute, Beijing
[2] Mine Safety Technology Branch, China Coal Research Institute, Beijing
[3] State Key Laboratory of Coal Mining and Clean Utilization, China Coal Research Institute, Beijing
来源：
| 2018年 / Academia Sinica卷 / 37期
基金：
中国国家自然科学基金; 国家重点研发计划;
关键词：
Acoustic emission; Coal and gas outburst; Foreshock period; Key structure body; Microseismic; Mining engineering; Precursory characteristics; Quiet period;
D O I：
10.13722/j.cnki.jrme.2017.1451
中图分类号：
学科分类号：
摘要：
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. © 2018, Science Press. All right reserved.
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页码：1419 / 1429
页数：10
相关论文
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