Expansionary Evolution Characteristics of Plastic Zone in Rock and Coal Mass Ahead of Excavation Face and the Mechanism of Coal and Gas Outburst

Liu, Hongtao; Guo, Litong; Zhao, Xidong

doi:10.3390/en13040984

Cited by 13 publications

(12 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The influence of tectonic, geostatic, and mining stresses on coal and gas outbursts (CGO) becomes more obvious with increasing mining depth [15][16][17][18]. Liu et al [19] established a mechanical analysis model of the expansion and evolution of the plastic zone in front of the driving face by numerical simulation method, analyzed the characteristics of the expansion and evolution of the plastic zone in front of the driving face, and discussed the physical and mechanical process and basic conditions of the development of coal and gas explosion caused by the evolution of the plastic zone. Zhang and Lowndes [20] used fault tree coupling analysis (FTA) and an artificial neural network (ANN) model to predict the potential risk of a coal and gas outburst during underground mining of thick and deep coal seams in China.…”

Section: Introductionmentioning

confidence: 99%

Coal and Gas Outburst Affected by Law of Small Fault Instability during Working Face Advance

et al. 2020

View full text Add to dashboard Cite

To analyze the effect of small faults in the working face on coal and gas outbursts, the coal and gas outburst accident in the 21431 working face was studied with the 3DEC numerical simulation method, and the main research contents were the change laws of both stresses at the small fault and the overburden strata movement rate in the small fault zone of which the drop height and the strike were designed into different groups. The results show that the risk of small fault slip increases with the advancing working face. In addition, there is a positive correlation between the risk and the small fault throw. The movement rate of overburden strata in the small fault zone increases along with the rising of the small fault throw, which increases the energy transferred to the coal seam from the surrounding rock under the effect of the small fault. Hence, the effect of small faults on the working face on coal and gas outbursts was positively correlated with the small fault throw. Under the influence of a small fault strike, the closer it is to the small fault along the dip distance at the same working face, the greater the risk will be of a coal and gas outburst. And the bigger the small fault strike is, the greater is the stress concentration degree in front of the working face and the more the elastic energy is stored and the greater is the possibility of an outburst. The paper analyzes the influence of small faults on coal and gas outbursts in the working face, which has reference significance for the prediction and prevention of coal and gas outburst disaster in the working face.

show abstract

Section: Introductionmentioning

confidence: 99%

Coal and Gas Outburst Affected by Law of Small Fault Instability during Working Face Advance

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The lunch of outburst indicates that some coal containing gas have experienced local damage, extensive failure, overall instability and throwing stage. Therefore, there are four periods for any particle failure of coal body in the outburst lunching area: initial failure period of ground stress, Stage of crack propagation by gas, outburst period of coal body instability, period of transportation and stop 49 .…”

Section: Experimental Phenomena and Failure Mechanismmentioning

confidence: 99%

Macroscopic fracture mechanism of coal body and evolution characteristics analysis of impact force in deep coal and gas outburst

Ren,

Tang,

Pan

et al. 2023

Sci Rep

View full text Add to dashboard Cite

With the increase of mining depth and intensity, coal and gas outburst dynamic disasters occur frequently. In order to deeply study the macroscopic fracture mechanism of coal body and evolution characteristics analysis of impact force, taking the outburst coal seam of Pingmei No. 11 Coal Mine and Sunjiawan coal seam of Hengda Coal Mine as the research objects, the simulation roadway test system of self-developed true triaxial coal and gas outburst is applied to carry out the simulation test of deep coal and gas outburst with buried depths of 1000 m, 1200 m, 1400 m and 1600 m. During the test, the overlying strata stress is simulated by axial compression, the surrounding rock stress is simulated by confining pressure, the gas pressure is simulated by pore pressure, the impact force and acoustic emission monitoring technology are introduced, and the coal seam gas pressure is simulated by mixture pressure of 45% CO2 and 55% N2. From the viewpoint of fracture mechanics, the crack propagation mechanism of coal in the outburst launching area is discussed, the evolution characteristics of impact force and gas pressure are analyzed, and the influence law between acoustic emission signal and impact force is revealed. From the viewpoint of energy conversion, the transformation character of gas internal energy to impact kinetic energy (gas pressure to impact force) are analyzed. The results show that the generation of I-type crack is a prerequisite for outburst catastrophe. With the crack propagation, I-type and II-type cracks intersect and penetrate, resulting in internal structural damage and skeleton instability of coal. Gas wrapped fragmentized coal body thrown, outburst occurs. There is obvious negative pressure in the roadway after outburst. The occurrence of negative pressure is greatly affected by the physical and mechanical properties of coal, ground stress and gas pressure. Impact kinetic energy is mainly provided by gas internal energy. Part of the gas pressure is converted into impact force. The strength and duration of the impact force are determined by the gas pressure. Under the condition of deep working conditions (high ground stress and low gas pressure), the propagation of impact force in the roadway is more hindered. Both impact force and acoustic emission signals can monitor the occurrence of outburst. The peak point of acoustic emission ringing count is earlier than the impact force. The acoustic emission signal can monitor the outburst hazard earlier. The impact force can more specifically reflect the coal fracture.

show abstract

“…It reflects the speed of gas release by coal resolution. Generally, when the standard gas content is the same, the higher the initial gas release velocity, the more serious the coal destruction, and the greater the coal and gas outburst risk [42]. Pressure factors mainly refer to high ground stress and coal seam gas pressure in deep coal mining.…”

Section: Gas Factorsmentioning

confidence: 99%

“…In this study, the mine and gas outburst risk levels are represented by 1, 2, 3, and 4, where 1 represents a low gas outburst risk (0-5.52 m 3 /t); 2 is a medium gas outburst risk (5.52-12.07 m 3 /t); 3 is a high gas burst risk (12.07-16.92 m 3 /t); and 4 is an extremely high gas burst risk (above 16.92 m 3 /t) [42]. A total of 124 sets were collected; the details are shown in Table 4.…”

Section: The Data Sourcementioning

confidence: 99%

Risk Assessment of Deep Coal and Gas Outbursts Based on IQPSO-SVM

Zhu

Yang

Wang

et al. 2022

IJERPH

View full text Add to dashboard Cite

Coal and gas outbursts seriously threaten the mining safety of deep coal mines. The evaluation of the risk grade of these events can effectively prevent the occurrence of safety accidents in deep coal mines. Characterized as a high-dimensional, nonlinear, and small-sample problem, a risk evaluation method for deep coal and gas outbursts based on an improved quantum particle swarm optimization support vector machine (IQPSO-SVM) was constructed by leveraging the unique advantages of a support vector machine (SVM) in solving small-sample, high-dimension, and nonlinear problems. Improved quantum particle swarm optimization (IQPSO) is used to optimize the penalty and kernel function parameters of SVM, which can solve the optimal local risk and premature convergence problems of particle swarm optimization (PSO) and quantum particle swarm optimization (QPSO) in the training process. The proposed algorithm can also balance the relationship between the global search and local search in the algorithm design to improve the parallelism, stability, robustness, global optimum, and model generalization ability of data fitting. The experimental results prove that, compared with the test results of the standard SVM, particle swarm optimization support vector machine (PSO-SVM), and quantum particle swarm optimization support vector machine (QPSO-SVM) models, IQPSO-SVM significantly improves the risk assessment accuracy of coal and gas outbursts in deep coal mines. Therefore, this study provides a new idea for the prevention of deep coal and gas outburst accidents based on risk prediction and also provides an essential reference for the scientific evaluation of other high-dimensional and nonlinear problems in other fields. This study can also provide a theoretical basis for preventing coal and gas outburst accidents in deep coal mines and help coal mining enterprises improve their safety management ability.

show abstract

Expansionary Evolution Characteristics of Plastic Zone in Rock and Coal Mass Ahead of Excavation Face and the Mechanism of Coal and Gas Outburst

Cited by 13 publications

References 23 publications

Coal and Gas Outburst Affected by Law of Small Fault Instability during Working Face Advance

Coal and Gas Outburst Affected by Law of Small Fault Instability during Working Face Advance

Macroscopic fracture mechanism of coal body and evolution characteristics analysis of impact force in deep coal and gas outburst

Risk Assessment of Deep Coal and Gas Outbursts Based on IQPSO-SVM

Contact Info

Product

Resources

About