Research on Joint Protection Layers and Gas Prevention Technology in Outburst Coal Seams

Zhang, Feng; Zhang, Jinshan

doi:10.3390/su14148859

Cited by 3 publications

(2 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…According to the existing research results, it can be known that the stress redistribution of surrounding rock caused by mining has great influences on the development of cracks in the roof and overlying strata, gas desorption, and seepage in coal seams. In the process of coal mining, the mining stress changes, and the overlying strata move and fracture under the influence of mining, accompanied by the development and evolution of mining cracks [10][11][12], and then the gas migrates in the cracks [13]. Therefore, it is the foundation and key to studying the stress distribution characteristics and crack evolution laws of the surrounding rock.…”

Section: Introductionmentioning

confidence: 99%

Study on the Coupling Effect of Stress Field and Gas Field in Surrounding Rock of Stope and Gas Migration Law

Li,

Wang

2023

Energies

View full text Add to dashboard Cite

In the process of working face mining, the permeability of the coal seam and the crack evolution characteristics of overlying strata are very important for efficient gas drainage. In this study, the distribution characteristics of the stress field and crack field in the working face and their relations are analyzed mainly by 3DEC numerical simulation. Furthermore, combined with the on-site measurement of coal seam stress, gas pressure, and gas seepage in front of the working face and the gas seepage in overlying strata before and after mining, the coupling effect of stress field and gas field and the law of gas migration and distribution in the working face are deeply explored. The results show that the changing trend of gas seepage and gas pressure is controlled by the stress change of the working face, and with the increase of stress, gas pressure and gas seepage also increase. The peak position of gas pressure is the farthest from the coal wall, about 22.5~25 m, followed by the peak of stress and gas seepage. When the permeability of coal and rock mass increases, the gas seepage increases and the gas pressure decreases. The coal seam stress and gas seepage in the working face and gas seepage in the overlying strata fracture zone along the tailgate side are generally greater than those on the headgate side, but the gas pressure is the opposite. Mining cracks and strata separation provide a good channel and space for gas migration and accumulation. Along the strike and tendency of the working face, gas is mainly concentrated in the overlying strata crack space above the separation zone and the roof and overlying strata crack space on the side of the tailgate, respectively. Based on this, the directional borehole gas drainage technology and borehole layout scheme in the fractured zone are put forward, which effectively reduce the gas concentration in the working face by 30~36%.

show abstract

Section: Introductionmentioning

confidence: 99%

Study on the Coupling Effect of Stress Field and Gas Field in Surrounding Rock of Stope and Gas Migration Law

Li,

Wang

2023

Energies

View full text Add to dashboard Cite

show abstract

“…The massive methane existing in coal seams will be released into mining space once its initial state changes, resulting in combustion and explosion when the methane concentration reaches a certain range, also causing severe damage and loss of life [9]. Successfully, lots of investigations have been carried out and numerous breakthroughs have been taken [4,[9][10][11][12][13], the timely degassing from coal seams gradually becomes the main means of preventing outbursts and methane explosions. Moreover, the understanding that outburst is dependent on the physicomechanical properties of coal, in situ stresses, and gas adsorption has been commonly adopted.…”

Section: Introductionmentioning

confidence: 99%

On Gas Desorption-Diffusion Regularity of Bituminous Coal with Different Particle Sizes and Its Influence on Outburst-Coal Breaking

et al. 2023

View full text Add to dashboard Cite

Coal and gas outburst is an urgent and constantly perplexing problem with coal resource extraction, threatening coal mine safe and sustainable production severely. Its mechanism and the participation of gas in coal breaking are still unclear. To explore this problem, in this paper, gas desorption-diffusion regularity of bituminous coal with different particle sizes and its influence on outburst-coal breaking were investigated through mercury intrusion porosimetry (MIP) tests, isothermal adsorption tests, and desorption-diffusion tests for coal particles with different sizes. The results indicated that the cumulative diffusion amount (Qt) and rate (Qt/Q∞), the effective diffusion coefficient (D′), and the kinetic diffusion parameter (υ) decreased as particle size increased. That meant gas was easier to desorb and diffuse from the smaller coal blocks, consequently making coal break into more tiny particles and accelerating gas desorption. As a result, a positive feedback effect that coal breaks continuously and gas releases rapidly and abundantly was formed in a short time when outbursts started, which caused gas release in quantities and promoted the occurrence of outbursts. The findings of this study enhance our understanding of the mechanism of gas participating in coal fragmentation during outbursts, which are significantly conducive to the prevention and control of coal mine disasters and sustainable production of coal resources.

show abstract

Evolution of fissures and pressure discharge of gas caused by mining of the upper protective layer of a coal seam

Xie

Cai

et al. 2023

Sci Rep

View full text Add to dashboard Cite

The evolution of fissures and permeability associated with mining of the upper protective layer of the coal seam is crucial for pressure relief gas drainage of the underlying seam. To understand the influence of mining the upper protective layer on gas drainage within the underlying coal seam, this study utilized the M16 and M18 seams in the Qinglong Coal Mine in Guizhou. Theoretical analysis, discrete element numerical simulation, and field tests were used to characterize the evolution of fractures associated with mining of the upper protective layer and the effects of pressure relief gas drainage within the protected coal seam. The results show that mining-related stress changes controlled the development of fractures, altering the permeability values of coals. An analysis of the crack development in the coal mass caused by mining of the upper protective layer shows that during the initial stage of mining, the produced cracks exhibited a butterfly shape network. Yet, with further development of the mining, these cracks and the stress changes gradually produced an inverted butterfly shape network. According to simulations, the areas of maximum deformation via expansion in the protected coal seam were located near the open cut and the mining end line of the working face. The maximum deformation values were 29.06 and 26.68 mm, respectively, and the corresponding deformation rates were 9.37‰ and 8.61‰, which are greater than the required 3‰. The findings of this study provide a new reference for gas control in pressure relief coal seams under similar working conditions.

show abstract

Research on Joint Protection Layers and Gas Prevention Technology in Outburst Coal Seams

Cited by 3 publications

References 31 publications

Study on the Coupling Effect of Stress Field and Gas Field in Surrounding Rock of Stope and Gas Migration Law

Study on the Coupling Effect of Stress Field and Gas Field in Surrounding Rock of Stope and Gas Migration Law

On Gas Desorption-Diffusion Regularity of Bituminous Coal with Different Particle Sizes and Its Influence on Outburst-Coal Breaking

Evolution of fissures and pressure discharge of gas caused by mining of the upper protective layer of a coal seam

Contact Info

Product

Resources

About