Changes in Frequency of Electromagnetic Radiation from Loaded Coal Rock

Song, Dazhao; Wang, Enyuan; Song, Xiaoyan; Jin, Peijian; Qiu, Liming

doi:10.1007/s00603-015-0738-6

Cited by 60 publications

(20 citation statements)

References 24 publications

(20 reference statements)

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“…Further, some flat phenomenon existed and the amplitude of frequency distribution increased considerably as the time-domain signal pulse improved, which is the ranging between 1 and 100 Hz. Thus, it can be inferred that the charge is a type of lowfrequency signal with primary frequency distribution from 1 to 100 Hz, the feature of frequency is the most significant difference between charge induction and electromagnetic radiation (Frid et al 2003(Frid et al , 2004(Frid et al , 2005Song et al 2012Song et al , 2016.…”

Section: Charge Signal Time-frequency Characteristics During Coal Faimentioning

confidence: 99%

“…Frid et al (2003); Bahat et al (2004); Rabinovitch et al (2005) obtained a relationship between the width of a fracture and the wavelength, frequency, time duration, and rise-fall time of the emitted electromagnetic radiation (EMR) pulse. Song et al (2012Song et al ( , 2016 analyzed the EMR and dissipated energy, and a relationship between them was established using the voltage amplitude of the EMR signal during the coal failure process. Pan et al (2013); Xiao et al (2015) explored charge signal law under different loading rates of coal, granite, and sand rock, and explained the charge generation mechanism from a microscopic viewpoint.…”

Section: Introductionmentioning

confidence: 99%

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Mechanical properties and charge signal characteristics in coal material failure under different loading paths

Ding

Xiao

et al. 2019

Int J Coal Sci Technol

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Rock burst is a catastrophic dynamic disaster caused by sudden failure and instability of coal, loading paths play an important role in the failure of coal, the coal failure process is associated with charge exception information. Hence, violent coal failure mechanics and time-frequency domain distribution of charge signal such as rock burst under different loading paths should be studied in-depth. In this paper, grade and cyclic loading test were carried out for coal with impact tendency samples produced by blocks cored from 800 depth in Xiaoqing coal mine of the Tiefa coal group in northeast China. Theory discussion was carried out for the result of stress and strain, frequency-spectra analysis was conducted for the wavelet charge data, figures showing the evolution mechanism of mechanical properties and the relationship of timefrequency domain amplitude of charge signals in coal with different loading paths and stage were obtained. The failure process and characteristics of coal under different loading paths were summarized. It found that the loading path changed the manner of energy accelerate-release, there were more plastic strain generation in coal under cyclic loading than that under grade loading, the former was more likely to cause greater damage and failure, then the strength of coal under cyclic loading is generally lower than that under grade loading, an energy conversion mechanical model of stress, damage and deformation was developed and explained the effect of the loading path. Charge signal was primarily distributed in the strengthening and peak stages, where there was a high amplitude pulse at each stress drop. The charge pulse was a type of low frequency signal with a primary frequency distribution range of 1-100 Hz. Discussion on the charge generating mechanism from the perspective of friction slip, it demonstrated that the charge obtained during the coal failure process directly to stress loaded on and damage, the result verified it better. We propose that the research results in this study could be efficiently applied to daily mining activities, to provide an early warning and effectively avoid rock burst disaster.

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Section: Charge Signal Time-frequency Characteristics During Coal Faimentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Mechanical properties and charge signal characteristics in coal material failure under different loading paths

Ding

Xiao

et al. 2019

Int J Coal Sci Technol

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“…A large number of research results [31,32,33] have shown that the intensity of EME can reflect the stress state of a coal and rock mass. When the stress is high, there is a large amount of deformation and damage in the coal body, and the intensity of EME is high.…”

Section: Field Applicationmentioning

confidence: 99%

Investigation of coal and gas outburst risk by microseismic monitoring

Wang

Song

et al. 2019

PLoS ONE

Self Cite

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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.

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“…AE is the release of energy from coal and rock mass in the wave form to be received by sensors. [22][23][24][25] Wang et al [26][27][28] applied the AE and electromagnetic radiation (EMR) system to coal and gas outburst monitoring and early warning and achieved good early warning results, which significantly improved the accuracy of outstanding warnings. [8][9][10][11] Moreover, this method only requires a small amount of work, does not occupy special working time, does not affect production, and has the technical advantages which the traditional forecast technologies do not have.…”

Section: Introductionmentioning

confidence: 99%

“…By comparing and analyzing the characterization parameters of AE, it was found that the AE ringing event could be used as one of the important parameters for coalrock dynamic disaster prediction. [22][23][24][25] Wang et al [26][27][28] applied the AE and electromagnetic radiation (EMR) system to coal and gas outburst monitoring and early warning and achieved good early warning results, which significantly improved the accuracy of outstanding warnings. Through relevant research, it is found that the current research on the AE precursor characteristics of gas-bearing rock mass failure is primarily conducted under laboratory conditions.…”

Section: Introductionmentioning

confidence: 99%

Acoustic emission monitoring technology for coal and gas outburst

et al. 2019

Energy Science & Engineering

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In recent years, with the increase in mining depth and strength, coal‐rock gas dynamic disasters, such as coal and gas outburst, have shown an increasing trend. Acoustic emission (AE) technology has been viewed as a promising method that can effectively forecast coal and gas dynamic disasters. This paper first tests the AE characteristics of coal and rock samples during loading. Then, self‐developed AE continuous monitoring and early warning equipment is used to monitor and predict the coal and gas outburst dynamic disasters on the working face. And it is found that the coal samples primarily show ductile failure, and the AE exhibits the evolutionary characteristics of “rise‐peak‐fall”. The rock samples primarily exhibit brittle failure, and the AE evolution mode is almost no falling stage. Coal and gas outbursts occur after the stress peak. Before coal and gas outbursts occur, there is a clear increasing trend in the AE ahead of the gas concentration variation. When the gas‐bearing coal is damaged by the load, the coal body first breaks due to the stress, and the AE value increases. Then, due to the fracture of the coal body, the crack penetrates, gas rushes out, and the gas concentration increases. The research results can provide an advanced technical method for the monitoring and early warning of coal–rock gas dynamic disasters, and improve the prediction accuracy for dynamic disasters.

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Changes in Frequency of Electromagnetic Radiation from Loaded Coal Rock

Cited by 60 publications

References 24 publications

Mechanical properties and charge signal characteristics in coal material failure under different loading paths

Mechanical properties and charge signal characteristics in coal material failure under different loading paths

Investigation of coal and gas outburst risk by microseismic monitoring

Acoustic emission monitoring technology for coal and gas outburst

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