4 results on '"Lou, Quan"'
Search Results
2. Investigation of coal and gas outburst risk by microseismic monitoring
- Author
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Wang Anhu, Zhenlei Li, Linming Dou, Dazhao Song, Xueqiu He, Ziyin Zu, Lou Quan, and Yingjie Zhao
- Subjects
Fossil Fuels ,0211 other engineering and technologies ,lcsh:Medicine ,02 engineering and technology ,010502 geochemistry & geophysics ,01 natural sciences ,Seismic wave ,Structural Geology ,Diagnostic Radiology ,Mathematical and Statistical Techniques ,Environmental monitoring ,Medicine and Health Sciences ,lcsh:Science ,Materials ,Tomography ,Seismology ,Multidisciplinary ,Radiology and Imaging ,Physics ,Continuous monitoring ,Statistics ,Classical Mechanics ,Geology ,Coal ,Geophysics ,Physical Sciences ,Engineering and Technology ,Organic Materials ,Research Article ,Environmental Monitoring ,Imaging Techniques ,Materials Science ,Fuels ,Natural Gas ,Research and Analysis Methods ,Vibration ,Mining engineering ,Seismic Signal Processing ,Diagnostic Medicine ,Humans ,Statistical Methods ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,Microseism ,business.industry ,lcsh:R ,Coal mining ,Models, Theoretical ,Coal Mining ,Stress field ,Energy and Power ,Signal Processing ,Earth Sciences ,Environmental science ,lcsh:Q ,business ,Energy (signal processing) ,Mathematics ,Forecasting - Abstract
In order to improve the monitoring and prediction of coal and gas outburst, this paper proposes a new method for dynamic regional prediction of coal and gas outburst using microseismic (MS) monitoring. The theoretical basis of this method is presented. An index evaluation system was established and applied, based on which field tests were carried out in a coal mine. The results show that seismic monitoring with frequency and energy indexes can obtain good results for mining disturbance intensity monitoring and geological structure detection; the regional stress distribution detected by seismic wave tomography is consistent with the theoretical stress field, making its use of great significance for optimizing coal and gas outburst drilling parameters and improving overall tunneling efficiency. This approach overcomes the limitations of traditional methods in the temporal and spatial dimensions and realizes dynamic and continuous monitoring of coal and gas outburst-prone areas.
- Published
- 2019
3. Mechanism and Prevention of Rockburst in Steeply Inclined and Extremely Thick Coal Seams for Fully Mechanized Top-Coal Caving Mining and Under Gob Filling Conditions.
- Author
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He, Shengquan, Song, Dazhao, Li, Zhenlei, He, Xueqiu, Chen, Jianqiang, Zhong, Taoping, and Lou, Quan
- Subjects
LONGWALL mining ,COAL ,STRESS concentration ,ELASTIC deformation ,COAL mining ,MECHANICAL models ,MINING engineering ,BLASTING - Abstract
The steeply inclined and extremely thick coal seams (SIETCS) under the condition of gob filling frequently suffer from the occurrence of rockbursts. Figuring out the mechanisms of rockbursts under this condition for taking targeted measures to mitigate rockburst hazards in SIETCS is of great significance. Using the typical SIETCS with an average dip angle of 87° at Wudong Coal Mine (WCM) as a case study, a mechanical model and elastic deformation energy (EDE) function of a "steeply inclined suspended roof structure" was developed, and the influence factors were analyzed by theoretical analysis. Simultaneously, the rockburst risk assessment was carried out based on the theory of a rockburst start-up. The pressure relief measures are optimized by comparing the pressure relief effects of three kinds of destress blasting schemes. The results indicate that the damage characteristics of rockburst are mainly floor heave, the sidewall's inward deformation and roof subsidence. The damage degree of headentry on the roof side is more severe than that of tailentry, and the resultant impacts showed the directionality from the roof side to the coal side. The steeply inclined and suspended roof breakage is one of the main causes for the occurrence of rockbursts. The EDE of the roof increases with an increasing dip angle of the coal seam from 0° to 72.6° and then decreases as the dip angle increases. Furthermore, that increase is accompanied by the decrease of the lateral pressure coefficient and the supporting force coefficient. The EDE stored in the roof is sufficient to cause roof breakage and induce rockburst after the complete roof exceeds a certain length. The mechanism of rockburst in SIETCS for fully mechanized top-coal caving mining under gob filling conditions was proposed, i.e., "high compressive stress concentration plus breakage of the suspended roof-induced stress" rockburst, and this is further verified by ground destruction, microseismic (MS) monitoring and numerical modeling. The results also indicate that alternate deep and shallow hole-blasting modes are more suitable for pressure relief in SIETCS. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
4. Research on electromagnetic radiation (EMR) waveform characteristics of coal failure process using Hilbert-Huang transform (HHT).
- Author
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Yin, Shan, Song, Dazhao, Li, Jie, He, Xueqiu, Qiu, Liming, Lou, Quan, Wei, Menghan, and Liu, Yang
- Subjects
- *
ELECTROMAGNETIC radiation , *HILBERT-Huang transform , *COAL , *WAVELET transforms , *FOURIER transforms - Abstract
• HHT method can well process and analyze the EMR waveform signal of coal failure. • The EMR parameters extracted by HHT improve the identification of coal failure. • Compared with STFT and WT, HHT has more advantages in processing EMR waveform. Electromagnetic radiation (EMR) waveforms contain rich information on coal fracture law, which is of great value to the refined study of their characteristics. In this paper, the Hilbert-Huang transform (HHT) method is used to analyze and process EMR waveform of coal failure process. The results show that HHT method can adapt well to the nonstationary and nonlinear characteristics of EMR waveform. It adaptively decomposes EMR waveforms by empirical mode decomposition (EMD), extracts the intrinsic mode function (IMF) characteristics of EMR waveforms, and obtains the law of instantaneous energy changes of EMR waveforms. At the same time, EMR waveform energy is quantitatively expressed on the three-dimensional Hilbert energy spectrum (time–frequency-energy distribution), and the refined features of EMR waveform signal are effectively extracted. The instantaneous energy of EMR and the three-dimensional Hilbert energy spectrum processed by HHT method more easily describe the fracture law of coal body. Compared with conventional characteristic parameters, such as EMR amplitude and dominant frequency, the identification degree of the precursor characteristics of coal body instability is greatly improved. Among the short-term Fourier transform (STFT), wavelet transform (WT) and HHT nonstationary signal processing methods, HHT method has an improved adaptability and superiority and can reveal the characteristics of coal deformation and failure more carefully and accurately, which provides a new means for better using and improving EMR method to monitor coal instability and failure. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
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