scholarly journals Maxwell-equations Based on Mining Transient Electromagnetic Method for Coal Mine-Disaster water Detection

2017 ◽  
Vol 23 (3) ◽  
Author(s):  
Benyu Su ◽  
Jingcun Yu ◽  
Chenxing Sheng
Keyword(s):  
Coal Mine ◽  
Maxwell Equations ◽  
Electromagnetic Method ◽  
Transient Electromagnetic Method ◽  
Water Detection ◽  
Transient Electromagnetic

scholarly journals Application of Comprehensive Geophysical Prospecting Method in Water Accumulation Exploration of Multilayer Goaf in Integrated Mine

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Lei Zhang ◽  
Lin Xu ◽  
Yong Xiao ◽  
NingBo Zhang
Keyword(s):  
Coal Seam ◽  
Coal Mine ◽  
Comprehensive Analysis ◽  
High Density ◽  
Electromagnetic Method ◽  
Mine Safety ◽  
Practical Significance ◽  
Time Base ◽  
Transient Electromagnetic Method ◽  
Transient Electromagnetic

A coal mine in Datong is an integrated mine. At present, there is goaf in the upper and lower part of the mining coal seam. There is a lot of ponding in the goaf, which has great potential safety hazards for production. In order to find out the scope and location of ponding in goaf, the comprehensive geophysical exploration method combining transient electromagnetic method and high-density resistivity method is used to carry out the research. Firstly, the time-base, turn-off time, receiving delay, current, superposition times, and other parameters of the instrument are tested on the surface of known goaf to obtain the best instrument parameters, and the parameters are used to verify the feasibility of the research scheme; then, the transient electromagnetic method is used for large-area exploration on the surface of the mine, the suspected goaf ponding area is found through comprehensive analysis, and the high-density resistivity exploration is arranged in the suspected goaf ponding area. According to the obtained results, the scope and location of the goaf ponding area are accurately located through comprehensive analysis. The results show that there are two goaf ponding areas in the exploration area, which are located above the 8# coal seam currently mined; the range and location of goaf ponding area can be accurately obtained by using the comprehensive geophysical method of high-density electrical method and transient electromagnetic method. This method can provide reference for mine water prevention and control in Datong area and has great practical significance to ensure coal mine safety production.

Application of Transient Electromagnetic Methods to the Safety Surveying of Coal Mines Production in the Datong Coalfield, China

2021 ◽  
Keyword(s):  
Coal Mine ◽  
Coal Mines ◽  
Electromagnetic Method ◽  
Transient Electromagnetic Method ◽  
Transient Electromagnetic ◽  
Electromagnetic Methods ◽  
Water Hazard

There were a lot of water hazard accidents in coal mines, due to the lacking of effective methods for the coalfield surveying. The transient electromagnetic approach is one of such methods and was applied to examine the safety surveying of coal mine in the Datong coal mines during last two decades. Although there had been many successful cases of using the methods to the surveying of gobs water, meanwhile there were some difficulties to accurately detect and measure the size and location of gob water points, which still need to refine the advance of transient electromagnetic method.

scholarly journals Application of Comprehensive Geophysical Prospecting Method in the Exploration of Coal Mined-Out Areas

2019 ◽  
Vol 2019 ◽  
pp. 1-17
Author(s):  
Xiao Luo ◽  
Shuang Gong ◽  
Zhonggang Huo ◽  
Hongyan Li ◽  
Xinpin Ding
Keyword(s):  
Coal Mine ◽  
Coal Mines ◽  
Electromagnetic Method ◽  
Open Pit ◽  
Transient Electromagnetic Method ◽  
Audio Frequency ◽  
Geophysical Prospecting ◽  
Controlled Source ◽  
Transient Electromagnetic ◽  
Research Profile

Due to the influence of mining technology, some coal mines will leave mined-out areas (or goafs) in the rock mass after mining. If the distribution law and influence scope of mined-out areas cannot be accurately explored and controlled, it will bring great potential safety hazards to subsequent coal mining and cause serious harm to adjacent houses, roads, bridges, railways, and so on. The unmanned aerial vehicle (UAV) aerial survey is used to accurately acquire the three-dimensional model of the slope in the key area of Yuanbaoshan open-pit coal mine, which provides basic information for the real-time visualization of the open-pit mine and the establishment of the engineering geological research profile. And the distribution of mined-out areas and water accumulation in the coal mine are investigated in detail by using the comprehensive geophysical prospecting method of the transient electromagnetic method (TEM) and controlled source audio-frequency magnetotellurics (CSAMT). Then, the borehole detection method is used to verify the goaf range obtained from comprehensive geophysical prospecting, and the results show good consistency. In addition, based on the results of borehole exploration and the comprehensive analysis of the borehole image, the instantaneous water level elevation in goaf and the development height of the water-conducting fracture zone and caving zone are concluded. Finally, the distribution of coal mined-out areas in the exploration area is obtained, and the results show that through the use of the transient electromagnetic method and controlled source audio-frequency magnetotellurics method, combined with drilling detection methods, the purpose of accurate exploration of mined-out areas in coal mines can be achieved.

scholarly journals Quantitative Calculation of Aquifer Water Quantity Using TEM Data

2017 ◽  
Vol 21 (1) ◽  
pp. 51
Author(s):  
Lanying Huang ◽  
Shengdong Liu ◽  
Bo Wang ◽  
Fubao Zhou
Keyword(s):  
Coal Mine ◽  
Mine Water ◽  
Apparent Resistivity ◽  
Electromagnetic Method ◽  
Water Quantity ◽  
Water Volume ◽  
Water Yield ◽  
Projection Area ◽  
Transient Electromagnetic Method ◽  
Transient Electromagnetic

Mine water is a menace to coal mining. Mine water quantity is generally detected by drilling in the coal mine roadway, and the disadvantage is high workload and low efficiency. Therefore, transient electromagnetic method (TEM) was proposed, and TEM data was processed to detect the water yield property of a targeted layer in coal mine. Through a mine-oriented 3D Transient Electromagnetic Method observing system, the signal of induced voltage is obtainable. Transient Electromagnetic Method 3D data volume can be calculated through the calculation of all-time resistivity and time-depth conversion. After an appropriate apparent resistivity value is set, the spatial distribution range of an aquifer can be determined. Then, with water-filling coefficient of the aquifer, its water quantity can be estimated. The water yield property detection results in the No.4 coal seam goaf of the No.80101 workface in Jude Mine of Shanxi, China, demonstrates that the apparent resistivity of this goaf is less than 3 Ω.m, and the projection area of low-resistivity anomaly zone is 22,383 m2. By using the formula Q=KMS, we can estimate that the water volume is 33,574 m3. Three boreholes have been constructed for the later dredging and drainage project, which results in a total water yield of 33,089 m3. The error percentage of the predicted water quantity is less than 1.5%. It can thus be concluded that it is feasible to predict aquifer water content with TEM data. Cálculo cuantitativo del volumen de aguas subterráneas a través del Método Electromagnético Transitorio (TEM)ResumenEl agua al interior de las minas es una amenaza para la minería de carbón. La cantidad del agua en las minas se detecta al perforar en las vías del socavón, con la desventaja de la carga de trabajo y la baja eficacia que significan. Por esto, el presente trabajo propone el Método Electromagnético Transitorio (TEM, del inglés Transient Electromagnetic Method) y utiliza la información generada para detectar las propiedades de producción de agua en una capa específica de una mina de carbón. A través de un sistema de observación tridimensional TEM orientado a minas se puede obtener la señal del voltaje inducido. La capacidad de la información del sistema TEM tridimensional se puede calcular al obtener la resistividad y la conversión tiempo-profundidad. Tan pronto se establece el valor apropiado de la resistividad aparente se puede determinar el rango de distribución de un acuífero. Luego, con el coeficiente de saturación del acuífero se puede calcular la cantidad de agua. Los resultados de la detección de las propiedades de producción de agua en la mina abandonada número cuatro de frente de trabajo número 80101 de la mina Jude, en Shanxi, China, demostró que la resistividad aparente de esta excavación es de 3 Ω.m, y el área de proyección de la zona anómala de baja resistividad es 22.383 m2. Al usar la fórmula Q=KMS, se estimó que el volumen de agua es de 33,574 m3. Tres pozos se han construido para el próximo proyecto de dragado y drenaje, cuyos resultados de producción de agua es de 33,089 m3. El porcentaje de error de la predicción de la cantidad de agua es menor al 1.5 %. Se concluye, por ende, que es factible producir el contenido de agua de un acuífero con la información del TEM.

scholarly journals Simulation Research and Application on Response Characteristics of Detecting Water-filled Goaf by Transient Electromagnetic Method

2021 ◽  
Author(s):  
Tingye Qi ◽  
Xiaoming Pei ◽  
Guorui Feng ◽  
Huiru Wei
Keyword(s):  
Numerical Simulation ◽  
Coal Mine ◽  
Water Inrush ◽  
Electromagnetic Method ◽  
Transient Electromagnetic Method ◽  
Induced Voltage ◽  
Measuring Point ◽  
Response Characteristics ◽  
Transient Electromagnetic ◽  
Water Accumulation

Abstract Water inrush disasters poses a great threat to the safe exploitation of coal resources. To solve this problem, the transient electromagnetic method(TEM) was proposed to accurately detect the water accumulation in the goaf. The electromagnetic response characteristics of different water-filled goaves were studied by electromagnetic field theory, numerical simulation and field verification. Through the models of 100% water accumulation, 50% water accumulation, 0% water accumulation, 100% water accumulation with collapsed rock, 50% water accumulation with collapsed rock and 0% water accumulation with collapsed rock goaf, the characteristics of induced voltage attenuation curves were studied. Meanwhile, the relationship between the attenuation voltage value and area of the transmitting coil and the depth of the goaf were also simulated. The results illustrate that the attenuation curve of induced voltage presented a regular exponential decay form in the 0% water accumulation model but existed abnormal exaltation for voltage in water-filled model. Through the linear fitting curve, it can be seen that the abnormal intensity of the induced voltage becomes stronger as the distance between the measuring point and the center of the target decrement. Moreover, the abnormal amplitude of the induced voltage increases with the rise of the water accumulation and collapsed rock will weakly reduce the low-resistance anomalous effect on the water-accumulated goaf. In addition, the response value of the attenuation voltage increased in second-order as the area of the transmitting coil increases, but decreased in third-order as the depth of the target body increases. The field detection results of the Majiliang coal mine also confirmed the theoretical analysis and the numerical simulation. The conclusions had important guiding significance for accurate detection of coal mine goaf.

scholarly journals Small multi-turn coils based on transient electromagnetic method for coal mine detection

2019 ◽  
Vol 169 ◽  
pp. 165-173 ◽  
Author(s):  
Hongzhi Tang ◽  
Haiyan Yang ◽  
Guangyin Lu ◽  
Shenen Chen ◽  
Jianhua Yue ◽  
...  
Keyword(s):  
Coal Mine ◽  
Electromagnetic Method ◽  
Transient Electromagnetic Method ◽  
Mine Detection ◽  
Transient Electromagnetic
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