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

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.

scholarly journals GA-Based Early Warning Method for Rock Burst with Microseismic and Acoustic Emission in Steeply Inclined Coal Seam

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Yarong Xue ◽  
Dazhao Song ◽  
Zhenlei Li ◽  
Jianqiang Chen ◽  
Xueqiu He ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Rock Burst ◽  
Coal Mine ◽  
Early Warning ◽  
Characteristic Parameter ◽  
Control Measures ◽  
Risk Level ◽  
Parameter System ◽  
Fitness Value ◽  
Rock Burst Risk

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.

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

2020 ◽  
Vol 279 ◽  
pp. 105755 ◽  
Author(s):  
Liming Qiu ◽  
Zhentang Liu ◽  
Enyuan Wang ◽  
Xueqiu He ◽  
Junjun Feng ◽  
...  
Keyword(s):  
Electromagnetic Radiation ◽  
Rock Burst ◽  
Coal Mine ◽  
Early Warning ◽  
Low Frequency

scholarly journals Reasonable Determination of Terminal Mining Lines Using the Stress Field with Seismic Wave Excitation in Deep Coalfaces

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Guang-an Zhu ◽  
Huan Liu ◽  
Bo-ru Su ◽  
Qi-peng Jiang ◽  
Hai-yang Liu
Keyword(s):  
Stress Field ◽  
Theoretical Analysis ◽  
Rock Burst ◽  
Seismic Wave ◽  
Coal Mine ◽  
Evaluation Method ◽  
Coal Pillar ◽  
Field Observations ◽  
Wave Excitation ◽  
Rock Burst Risk

Many field observations have shown that rock bursts occur frequently near the terminal mining line (TML) and dip coal pillar area in deep coalfaces. Taking the “7.26” rock burst in coalface 3302 in Xingcun Coal Mine as an example, the rock burst mechanism was investigated based on theoretical analysis and field observations, and a combined evaluation method using the stress field under seismic wave excitation was established to determine the reasonable TML of coalface 3302. Firstly, the static geological data revealed during roadway excavation were used for preevaluation of rock burst risk at the working face. By theoretically analyzing the stress transfer mechanism of the two types of the roof structure, the computational model of abutment pressure was established and the calculation method giving the abutment stress was proposed. Subsequently, a dynamic evaluation method that adopts microseismic and stress online monitoring system to monitor dynamic information, such as mine tremors and stress during coalface mining, was developed to define stress anomaly areas and then dynamically determine the TML. Finally, the proposed model was used to optimize the position of the TML of LW3302 in Xingcun Coal Mine; findings obtained in this study provide theoretical guidance for safe coal mining. Combined with the results of theoretical analysis (255 m), online stress monitoring (200 m), microseismic (MS) monitoring (262 m), and passive seismic velocity tomography (220–250 m), it can be finally determined that the width of the protective coal pillar for the TML of coalface 3302 should be at least 262 m.

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

Energies ◽  
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.

scholarly journals Comprehensive early warning of rock burst utilizing microseismic multi-parameter indices

2018 ◽  
Vol 28 (5) ◽  
pp. 767-774 ◽  
Author(s):  
Linming Dou ◽  
Wu Cai ◽  
Anye Cao ◽  
Wenhao Guo
Keyword(s):  
Rock Burst ◽  
Early Warning

scholarly journals Multistage identification method for real-time abnormal events of streaming data

2019 ◽  
Vol 15 (12) ◽  
pp. 155014771989454
Author(s):  
Hao Luo ◽  
Kexin Sun ◽  
Junlu Wang ◽  
Chengfeng Liu ◽  
Linlin Ding ◽  
...  
Keyword(s):  
Real Time ◽  
Coal Mine ◽  
Early Warning ◽  
Sliding Window ◽  
Geological Structure ◽  
Streaming Data ◽  
Event Monitoring ◽  
Monitoring Method ◽  
Identification Method ◽  
Abnormal Events

With the development of streaming data processing technology, real-time event monitoring and querying has become a hot issue in this field. In this article, an investigation based on coal mine disaster events is carried out, and a new anti-aliasing model for abnormal events is proposed, as well as a multistage identification method. Coal mine micro-seismic signal is of great importance in the investigation of vibration characteristic, attenuation law, and disaster assessment of coal mine disasters. However, as affected by factors like geological structure and energy losses, the micro-seismic signals of the same kind of disasters may produce data drift in the time domain transmission, such as weak or enhanced signals, which affects the accuracy of the identification of abnormal events (“the coal mine disaster events”). The current mine disaster event monitoring method is a lagged identification, which is based on monitoring a series of sensors with a 10-s-long data waveform as the monitoring unit. The identification method proposed in this article first takes advantages of the dynamic time warping algorithm, which is widely applied in the field of audio recognition, to build an anti-aliasing model and identifies whether the perceived data are disaster signal based on the similarity fitting between them and the template waveform of historical disaster data, and second, since the real-time monitoring data are continuous streaming data, it is necessary to identify the start point of the disaster waveform before the identification of the disaster signal. Therefore, this article proposes a strategy based on a variable sliding window to align two waveforms, locating the start point of perceptual disaster wave and template wave by gradually sliding the perceptual window, which can guarantee the accuracy of the matching. Finally, this article proposes a multistage identification mechanism based on the sliding window matching strategy and the characteristics of the waveforms of coal mine disasters, adjusting the early warning level according to the identification extent of the disaster signal, which increases the early warning level gradually with the successful result of the matching of 1/ N size of the template, and the piecewise aggregate approximation method is used to optimize the calculation process. Experimental results show that the method proposed in this article is more accurate and be used in real time.

Sign in / Sign up

Export Citation Format

Share Document