Safety technologies for the excavation of coal and gas outburst-prone coal seams in deep shafts

2013 ◽  
Vol 57 ◽  
pp. 24-33 ◽  
Author(s):  
Liang Wang ◽  
Yuan-ping Cheng ◽  
Chun-gui Ge ◽  
Jia-xiang Chen ◽  
Wei Li ◽  
...  
Keyword(s):  
Coal And Gas Outburst ◽  
Coal Seams ◽  
Gas Outburst

Safe strategy for coal and gas outburst prevention in deep-and-thick coal seams using a soft rock protective layer mining

2020 ◽  
Vol 129 ◽  
pp. 104800 ◽  
Author(s):  
Liang Wang ◽  
Zhuang Lu ◽  
Da-peng Chen ◽  
Qing-quan Liu ◽  
Peng Chu ◽  
...  
Keyword(s):  
Soft Rock ◽  
Protective Layer ◽  
Coal And Gas Outburst ◽  
Coal Seams ◽  
Gas Outburst ◽  
Safe Strategy

scholarly journals Risk assessment method of coal and gas outburst based on improved comprehensive weighting and cloud theory

2021 ◽  
pp. 014459872110558
Author(s):  
Chunhua Zhang ◽  
Dengming Jiao ◽  
Ziwen Dong ◽  
Hongyu Zhang
Keyword(s):  
Risk Assessment ◽  
Coal Seam ◽  
Ideal Point ◽  
Assessment Method ◽  
Coal And Gas Outburst ◽  
Coal Seams ◽  
Gas Outburst ◽  
Risk Assessment Method ◽  
Cloud Theory ◽  
Assessment Results

Risk assessment is an effective method of accident prevention and is vital to actual production. To reduce the risk of mining accidents and realize green and sustainable coal mining, a coal and gas outburst risk assessment method based on the improved comprehensive weight and cloud theory is proposed. The proposed method can effectively solve problems of fuzziness and randomness, index weight deviation, and correlation between indexes in risk assessment, as well as improve the accuracy and rationality of assessment. Nine influencing factors that correspond to coal seam occurrence and geological characteristics, coal seam physical characteristics, and gas occurrence characteristics are selected to establish the risk assessment index system of coal and gas outburst. Using the improved group G1 method and improved CRITIC method to obtain the subjective and objective weights, the ideal point method is used to obtain the comprehensive weight. Using the normal cloud model of cloud theory and the comprehensive weight to assess engineering examples 1–2, the No. 3 coal seam of a mine in Shanxi, and the 21 coal seam of a mine in Henan, the risk grade of coal and gas outburst is determined and then compared with the assessment results obtained from the engineering examples and the actual situations of the above mentioned coal seams. The results show that the coal and gas outburst risks of engineering examples 1–2, No. 3 coal seam, and 21 coal seam are of grades IV, IV, II, and IV, respectively. The No. 3 coal seam and 21 coal seam belong to lower and higher risk categories, respectively. The assessment results are consistent with the actual situation of the coal seams, thereby confirming the rationality and accuracy of the proposed method. This study expands the methods of coal and gas outburst risk assessment and facilitates the formulation of effective preventive measures.

Features of Jianshanchong Klippe and its Control to Gas Geology at Qingshan Coal Mine, Jiangxi Province

2012 ◽  
Vol 164 ◽  
pp. 501-505
Author(s):  
Zhi Gen Zhao ◽  
Jia Chen ◽  
Jia Ping Yan
Keyword(s):  
Coal Seam ◽  
Coal Mine ◽  
Emission Rate ◽  
Coal And Gas Outburst ◽  
Jiangxi Province ◽  
Coal Seams ◽  
Gas Emission ◽  
Gas Outburst ◽  
Transverse Profile ◽  
Tectonic Coal

The coal and gas outburst is serious at Qingshan Coal Mine of Jiangxi Province, so it is of significance to research the features of Jianshanchong klippe and its control to gas geology. The research reveals that: Jianshanchong klippe is distributed from the east boundary of Qingshan Coal Mine to No. 45 Exploration Line, its transverse profile is like a funnel while its longitudinal profile is like a wedge, northwest side of the klippe is thicker and deeper while southeast side is thinner and more shallow. Because of the cover and insert of Jianshanchong klippe, the structure of coal-bearing strata is more complex, some secondary folds are formed, and also, the coal seam is changed greatly, the tectonic coal is well developed and the coal seam is suddenly thickening or thinning. Due to the effect of Jianshanchong klippe, the coal and gas outbursts occur in the area of secondary folds, thicker coal seams or tectonic coals. Concerning the prediction of gas geology in deep area, in view of the facts including simpler structure, stable coal seam and decreased thickness, the gas emission rate and the coal and gas outburst will decrease in Fifth and Sixth Mining Level than that in Second and Third Mining Level

The Preventing Coal and Gas Outburst Technology of Middle Distance and Low Permeability and Upper Protective Layer

2013 ◽  
Vol 690-693 ◽  
pp. 3059-3067 ◽  
Author(s):  
Guo Wei Dong
Keyword(s):  
Protective Layer ◽  
Mining Area ◽  
Coal And Gas Outburst ◽  
Low Permeability ◽  
Control Effect ◽  
Coal Seams ◽  
Gas Outburst ◽  
Protection Layer ◽  
And Control ◽  
Layer Control

Protective layer mining is the main regional measures for control coal and gas outburst . According to the defects of the preventing coal and gas outburst technology of middle distance and low permeability and upper protective layer in western Shuicheng mining area, the coal seams coal and gas outburst original danger are analyzed and protective layer is choosed initially using gas geological theory,the choice upper protective layer feasibility is analyzed using protection layer theory. the preventing coal and gas outburst technology of middle distance and low permeability and upper protective layer control effect is studied by numerical simulation and spot investigation. The conclusions from this research：the preventing coal and gas outburst technology of middle distance and low permeability and upper protective layer can decrease coal and gas outburst prediction index and control coal and gas outburst; the coal seams coal and gas outburst original danger can be preliminarily evaluated and the evaluation result can provide the basis for protective layer choice; the preventing coal and gas outburst technology of middle distance and low permeability and upper protective layer can be applied in western marine-continental transitional facies coal measure strata.

Study of Hydraulic Slotting Technology for Rapid Excavation of Coal Seams with Severe Coal and Gas Outburst Potentials

2013 ◽  
Vol 13 (17) ◽  
pp. 3483-3489 ◽  
Author(s):  
Yongjun Zhang ◽  
Guoying Wei ◽  
Zimin Zhang ◽  
Tianrang Jia ◽  
Dengfeng Yang
Keyword(s):  
Coal And Gas Outburst ◽  
Coal Seams ◽  
Gas Outburst ◽  
Rapid Excavation

scholarly journals Coupling Technology of Deep-Hole Presplitting Blasting and Hydraulic Fracturing Enhance Permeability Technology in Low-Permeability and Gas Outburst Coal Seam: A Case Study in the No. 8 Mine of Pingdingshan, China

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Wei Wang ◽  
Yanzhao Wei ◽  
Minggong Guo ◽  
Yanzhi Li
Keyword(s):  
Coal Seam ◽  
Hydraulic Fracturing ◽  
Complex Structure ◽  
Coal And Gas Outburst ◽  
Gas Content ◽  
Low Permeability ◽  
Gas Extraction ◽  
Deep Hole ◽  
Coal Seams ◽  
Gas Outburst

The current study aims to analyze the principles of integrated technology of explosion to tackle the problems of coal seam high gas content and pressure, developed faults, complex structure, low coal seam permeability, and high outburst risk. Based on this, we found through numerical simulation that as the inclination of the coal seam increases, the risk of coal and gas outburst increases during the tunneling process. Therefore, it is necessary to take measures to reduce the risk of coal and gas outburst. We conducted field engineering experiments. Our results show that the synergistic antireflection technology of hydraulic fracturing and deep-hole presplitting blasting has a significant antireflection effect in low-permeability coal seams. After implementing this technology, the distribution of coal moisture content was relatively uniform and improved the influence range of direction and tendency. Following 52 days of extraction, the average extraction concentration was 2.9 times that of the coal seam gas extraction concentration under the original technology. The average scalar volume of single hole gas extraction was increased by 7.7 times. Through field tests, the purpose of pressure relief and permeability enhancement in low-permeability coal seams was achieved. Moreover, the effect of gas drainage and treatment in low-permeability coal seams was improved, and the applicability, effectiveness, and safety of underground hydraulic fracturing and antireflection technology in low-permeability coal seams were verified. The new technique is promising for preventing and controlling gas hazards in the future.

Deformation Analysis for Coal and Gas Outburst Cavity

2011 ◽  
Vol 121-126 ◽  
pp. 2607-2613
Author(s):  
Qian Ting Hu ◽  
Wen Bin Wu ◽  
Guo Qiang Cheng
Keyword(s):  
Damage Zone ◽  
Coal And Gas Outburst ◽  
Gas Content ◽  
Combination Method ◽  
Deformation Analysis ◽  
Failure Zone ◽  
Finite Element Code ◽  
Cavity Volume ◽  
Gas Emission ◽  
Gas Outburst

Outburst cavity formed during coal and gas outburst can be pear shaped, elliptical, or just like an irregularly elongated ellipsoid, its capacity is always smaller than the volume of ejected coal. And the gas emission quantity is almost 4 to 10 times as gas content in ejected coal. These are two different expressions of the same problem. To find the reasons for the decrease of outburst cavity volume and the increase of gas emission quantity per ton, by using the finite element code ANSYS, the damage zone and the failure zone of the outburst cavity were determined based on the static and dynamic combination method. In this paper, the reason for the decrease of the outburst volume was explained.

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