Early-warning of rock burst in coal mine by low-frequency electromagnetic radiation

Aiming at problem of low efficacy of early warning of rock burst in coal mine, a multisystem and multiparameter integrated early warning method based on genetic algorithm (GA) is proposed. In this method, firstly, the temporal-spatial-intensity information of energy incubation process of rock burst is deeply mined, and the multidimensional precursory characteristic parameter system of rock burst is constructed. Secondly, the genetic algorithm is used to train the historical monitoring data to obtain the optimal critical value and fitness value of each precursory characteristic parameter, and then the early warning index WC of each monitoring system is calculated. Finally, the integrated rock burst early warning index IC is obtained by synthesizing the early warning index WC of each system. The value of IC corresponds to the specific rock burst risk level of the mine. This method is applied to Wudong coal mine in Xinjiang, China. Based on the actual situation of the mine, a multidimensional precursory characteristic parameter system of rock burst is constructed, which includes energy deviation (DE), frequency ratio (Fr), frequency deviation (DF), degree of dispersion (DS), and total high value of energy deviation (DH). After analyzing the rock burst danger status and risk level in the monitoring area, the early warning capability of this method is found to reach 0.896. Combining with the specific prevention and control measures corresponding to different rock burst risk levels, it can provide effective guidance for the field work.

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Electromagnetic radiation early warning criterion of rock burst based on statistical theory

Mining Science and Technology (China) ◽

10.1016/s1674-5264(09)60263-5 ◽

2010 ◽

Vol 20 (5) ◽

pp. 686-690 ◽

Cited By ~ 2

Author(s):

Dazhao SONG ◽

Enyuan WANG ◽

Chao WANG ◽

Fule XU

Keyword(s):

Statistical Theory ◽

Electromagnetic Radiation ◽

Rock Burst ◽

Early Warning

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Rock Burst Precursor Electromagnetic Radiation Signal Recognition Method and Early Warning Application Based on Recurrent Neural Networks

Rock Mechanics and Rock Engineering ◽

10.1007/s00603-020-02314-w ◽

2021 ◽

Author(s):

Yangyang Di ◽

Enyuan Wang

Keyword(s):

Neural Networks ◽

Electromagnetic Radiation ◽

Rock Burst ◽

Early Warning ◽

Recurrent Neural Networks ◽

Signal Recognition ◽

Recognition Method

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Pattern Recognition of Signals for the Fault-Slip Type of Rock Burst in Coal Mines

Shock and Vibration ◽

10.1155/2015/806969 ◽

2015 ◽

Vol 2015 ◽

pp. 1-8 ◽

Cited By ~ 4

Author(s):

X. S. Liu ◽

J. Tan ◽

Y. L. Tan ◽

S. C. Hu

Keyword(s):

Pattern Recognition ◽

Electromagnetic Radiation ◽

Rock Burst ◽

Early Warning ◽

Mechanical Model ◽

Fault Slip ◽

Coal Face ◽

Major Threat ◽

Good Agreement

The fault-slip type of rock burst is a major threat to the safety of coal mining, and effectively recognizing its signals patterns is the foundation for the early warning and prevention. At first, a mechanical model of the fault-slip was established and the mechanism of the rock burst induced by the fault-slip was revealed. Then, the patterns of the electromagnetic radiation, acoustic emission (AE), and microseismic signals in the fault-slip type of rock burst were proposed, in that before the rock burst occurs, the electromagnetic radiation intensity near the sliding surface increases rapidly, the AE energy rises exponentially, and the energy released by microseismic events experiences at least one peak and is close to the next peak. At last, in situ investigations were performed at number 1412 coal face in the Huafeng Mine, China. Results showed that the signals patterns proposed are in good agreement with the process of the fault-slip type of rock burst. The pattern recognition can provide a basis for the early warning and the implementation of relief measures of the fault-slip type of rock burst.

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Microseismic Signals in Heading Face of Tengdong Coal Mine and Their Application for Rock Burst Monitoring

Shock and Vibration ◽

10.1155/2021/6650446 ◽

2021 ◽

Vol 2021 ◽

pp. 1-13

Author(s):

JianJu Ren ◽

Wenlong Zhang ◽

Zheng Wu ◽

Ji Li ◽

Ying Shen

Keyword(s):

Rock Burst ◽

Coal Mine ◽

Early Warning ◽

Great Influence ◽

Field Tests ◽

Vibration Signal ◽

Propagation Distance ◽

Large Energy ◽

Rock Burst Risk ◽

Interference Signals

Microseismic (MS) monitoring is an important and commonly used geophysical method in coal mines to predict rock burst which has great influence on safety production. MS monitoring technology and analysis method of the whole mine or working face have been matured, but its use in heading faces of coal mine is not mature due to small disturbances and narrow layout spaces. To carry out MS monitoring and early warning in the heading face, signal recognition must be adequately performed first, and monitoring objects and indicators must be obtained. Through field tests of MS systems at the 117 track gateway of Tengdong coal mine, interference signals of equipment operation and effective signals of coal vibration are accurately collected. After analysis, the waveform characteristics, spectrum, and propagation distance of the interference signals and coal vibration signal are different. Some effective signals with small energy (one-channel triggering) cannot be used as early warning indicators because they are concealed by interference signals. Through trial operation, it is found that large energy (three-channel and four-channel triggering) coal vibration events successfully predicted a rock burst. The MS system of 117 track gateway of Tengdong coal mine should be able to remove the interference signals in real time through the algorithm and take the number of large energy coal vibration signal rather than all coal vibration events as the predictor for rock burst risk monitoring.

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Low Frequency Electromagnetic Radiation

IMA Journal of Applied Mathematics ◽

10.1093/imamat/23.4.421 ◽

1979 ◽

Vol 23 (4) ◽

pp. 421-447 ◽

Cited By ~ 31

Author(s):

D. S. JONES

Keyword(s):

Electromagnetic Radiation ◽

Low Frequency

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Directional Hydraulic Fracturing (DHF) of the Roof, as an Element of Rock Burst Prevention in the Light of Underground Observations and Numerical Modelling

Energies ◽

10.3390/en14030562 ◽

2021 ◽

Vol 14 (3) ◽

pp. 562

Author(s):

Marek Jendryś ◽

Andrzej Hadam ◽

Mateusz Ćwiękała

Keyword(s):

Rock Mass ◽

Hydraulic Fracturing ◽

Coal Mining ◽

Rock Burst ◽

Coal Mine ◽

Seismic Activity ◽

Black Coal ◽

Directional Hydraulic Fracturing ◽

Before And After ◽

The Face

The following article analyzes the effectiveness of directional hydraulic fracturing (DHF) as a method of rock burst prevention, used in black coal mining with a longwall system. In order to define changes in seismic activity due to DHF at the “Rydułtowy” Black Coal Mine (Upper Silesia, Poland), observations were made regarding the seismic activity of the rock mass during coal mining with a longwall system using roof layers collapse. The seismic activity was recorded in the area of the longwall itself, where, on a part of the runway, the rock mass was expanded before the face of the wall by interrupting the continuity of the rock layers using DHF. The following article presents measurements in the form of the number and the shock energy in the area of the observed longwall, which took place before and after the use of DHF. The second part of the article unveils the results of numerical modeling using the discrete element method, allowing to track the formation of goafs for the variant that does not take DHF into consideration, as well as with modeled fractures tracing DHF carried out in accordance with the technology used at “Rydułtowy” coal mine.

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