scholarly journals Development of a stress-based approach for achieving the risk assessment of fault-related coal and gas outburst

2019 ◽  
Vol 21 (4) ◽  
pp. 509
Author(s):  
Qinglong Zhou ◽  
Juan Herrera Herbert ◽  
Arturo Hidalgo
Keyword(s):  
Risk Assessment ◽  
Coal And Gas Outburst ◽  
Gas Outburst

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.

Risk Assessment on Coal and Gas Outburst Based on TOPSIS Model

2012 ◽  
Vol 608-609 ◽  
pp. 1483-1486
Author(s):  
Yu Zhong Yang ◽  
Li Yun Wu
Keyword(s):  
Risk Assessment ◽  
Safety Management ◽  
Mining Area ◽  
Coal And Gas Outburst ◽  
Mine Safety ◽  
Entropy Weight ◽  
Gas Outburst ◽  
Coal Mine Safety ◽  
Order Preference ◽  
Topsis Technique

Risk assessment on coal and gas outburst was necessary to Coal mine safety management. The model of TOPSIS(Technique for Order Preference by Similarity to Ideal Solution), which is based on entropy weight, was constructed to evaluate outburst risk. The subjectivity which lies in ascertaining factors’ weights was avoided in this model. So the evaluation result is more objective than other evaluation methods. The model was applied in the safety assessment of coal and gas outburst for four mining faces from east area of Ping Dingshan mining area. The order preference of outburst risk was gained. At the same time, the risk differences among four faces were attained. The evaluation results indicate that TOPSIS method be more reasonable and objective. It is easier to use in Coal mines.

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.

scholarly journals Mechanical criterion for coal and gas outburst: a perspective from multiphysics coupling

2021 ◽  
Author(s):  
Ting Liu ◽  
Baiquan Lin ◽  
Xuehai Fu ◽  
Ang Liu
Keyword(s):  
Control Method ◽  
Risk Identification ◽  
Controlling Factors ◽  
Gas Pressure ◽  
Critical Values ◽  
Coal And Gas Outburst ◽  
Strong Interactions ◽  
Gas Outburst ◽  
Multiphysics Coupling ◽  
Coal Strength

AbstractAlthough a series of hypotheses have been proposed, the mechanism underlying coal and gas outburst remains unclear. Given the low-index outbursts encountered in mining practice, we attempt to explore this mechanism using a multiphysics coupling model considering the effects of coal strength and gas mass transfer on failure. Based on force analysis of coal ahead of the heading face, a risk identification index Cm and a critical criterion (Cm ≥ 1) of coal instability are proposed. According to this criterion, the driving force of an outburst consists of stress and gas pressure gradients along the heading direction of the roadway, whereas resistance depends on the shear and tensile strengths of the coal. The results show that outburst risk decreases slightly, followed by a rapid increase, with increasing vertical stress, whereas it decreases with increasing coal strength and increases with gas pressure monotonically. Using the response surface method, a coupled multi-factor model for the risk identification index is developed. The results indicate strong interactions among the controlling factors. Moreover, the critical values of the factors corresponding to outburst change depending on the environment of the coal seams, rather than being constants. As the buried depth of a coal seam increases, the critical values of gas pressure and coal strength decrease slightly, followed by a rapid increase. According to its controlling factors, outburst can be divided into stress-dominated, coal-strength-dominated, gas-pressure-dominated, and multi-factor compound types. Based on this classification, a classified control method is proposed to enable more targeted outburst prevention.

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