Coal Anisotropic Sorption and Permeability: An Experimental Study

Chen, Yulong; Li, Xuelong; Li, Bo

doi:10.3390/pr6080104

Cited by 8 publications

(3 citation statements)

References 25 publications

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“…The derivative effect under the influence of mining can lead to rock bursting and coal and gas outbursts, so the stress evolution characteristics induced by mining have been widely studied. The existing research showed that each component of the 3D crustal stress tensor is always different in different directions, thus playing a major role in influencing the tightness and stability of a mining roadway [3][4][5]. High crustal stress increased the risk of coal and gas outbursts: in the horizontal direction, this and the principal stress intensity are the key factors affecting the risk of an outburst [6][7][8].…”

Section: Introductionmentioning

confidence: 99%

The Relationship between Mining-Induced Stress and Coal Gas under an Optimized Support Scheme: A Case Study in the Guanyinshan Coal Mine, China

Zhang

Chen

et al. 2021

Geofluids

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Stress is one of the main factors influencing coal and gas outbursts. The apparent effects of the crustal stress, the structural stress, and the mining-induced stress increase as the depth of mining increases. At present, there have been few studies of the relationship between the comprehensive analyses of the crustal stress, mining-induced stress, and coal gas. The in situ measurement of the relationship between stress-related behaviors and coal gas under the influence of mining was conducted through experimental analysis of surrounding rock support and coal and gas outburst control and optimization of surrounding rock support materials and system construction. The results showed that the mining-induced stress first increased to a peak value, then gradually decreased, and tended to stabilize as the footage progresses. Stress appears at 96 m ahead due to mining; after 57 m of advancing, there is a large increase until it passes through this area. The stress in front of the working face increases linearly, and the increase range is obviously larger than that of the coal body in a certain range on both sides. The support anchoring force gradually decreased and tended to be stable after rapidly increasing to a maximum value. The deep displacement of the roof increased linearly and tended to be stable after reaching an accumulated displacement which can reach 16-28 mm. The residual gas pressure in front of mining operations decreased rapidly, and beyond 15 m on each side of the roadway, it decreased significantly. The residual gas pressure and gas content were consistent with the gas desorption index of drill cuttings due to the influences of gas predrainage and mining. The stress along the direction of the roadway and the residual gas content, the residual gas pressure, and the gas desorption index of drill cuttings conform to the logarithmic functional relationship. The research results provide a basis for the comprehensive prevention and control of coal and gas outbursts from multiple angles considering stress, coal, and gas.

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Section: Introductionmentioning

confidence: 99%

The Relationship between Mining-Induced Stress and Coal Gas under an Optimized Support Scheme: A Case Study in the Guanyinshan Coal Mine, China

Zhang

Chen

et al. 2021

Geofluids

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“…Ten permeability measurements of coal show that the permeability of coal in parallel to the bedding plane in the butt cleat direction is higher than that in perpendicular to the bedding plane. Chen et al , studied the influence of mechanical and permeability properties of coal samples with different intersection angles in parallel and perpendicular to the bedding direction on the process of full stress–strain. Wang et al tested the permeability under the effective stress of 3.5–8.5 MPa, and the results show that the permeability of coal samples decreases exponentially with an increase in effective stress and the dimensionless permeability in parallel to the bedding direction is larger than that in perpendicular to the bedding direction.…”

Section: Introductionmentioning

confidence: 99%

Experiment and Modeling of Permeability under Different Impact Loads in a Structural Anisotropic Coal Body

Liang

Yue

et al. 2020

ACS Omega

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A mount of bedding and cleat in a coal body causes that the mechanical property and gas permeability are anisotropic in a coal seam, partly. To reveal the permeability change law of the impacted coal, a self-developed vertical split Hopkinson pressure bar (SHPB) device is used to carry out the dynamic impact mechanical property tests of coal samples in three different coring directions under five impact loads and then the permeability of the impacted coal samples is measured by a permeability measuring instrument under different gas pressures. Finally, a calculation model for the anisotropic coal permeability is established to analyze the permeability distribution law in any direction with different angles to the bedding plane. The results show that with an increase in impact height the dynamic peak stress of coal samples increases gradually, which shows a linear growth relationship. The permeability of the impacted coal samples is much larger than that of raw coal samples, and the bigger the impact load, the larger the permeability. Moreover, under the same impact load and gas pressure, the permeability is the largest in parallel to the bedding direction, followed by that in oblique 45°to the bedding direction, and the smallest in perpendicular to the bedding direction. The permeability calculated by the anisotropic model in oblique 45°to the bedding direction is in good agreement with the measured results, and the errors are no more than 10%, which will provide a theoretical basis for the permeability distribution law of the coal seam after deep-hole blasting.

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“…Yang et al [11] used the pressure pulse attenuation method to test the permeability of coal and rock before and after low temperature treatment and revealed the influence of liquid nitrogen injection on the permeability of coal seam. Chen et al [12] carried out an experimental study on the adsorption-desorption and permeability of anisotropic gases in coal. It was considered that the permeability of coal sample shows different changes at different stages.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on Mechanics and Permeability Properties of Water-Bearing Raw Coal Samples Under In-Situ Stress

Zhang

Wang

et al. 2019

Applied Sciences

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In this paper, we investigated the mechanical and permeability characteristics ofwater-bearing raw coal samples under in-situ stress, and came to some conclusions, as follows: thepeak strength and peak axial strain of samples gradually decrease with the increase of watercontent. Under the same stress condition, the higher the water content is, the lower the axial strainand radial strain will be. The peak strength and peak strain of the sample both decrease with thewater content as a quadratic function. During the post-peak loading and unloading process, withthe increase of the number of cycles of loading and unloading, the radial strain decrement andincrement of the raw coal sample gradually decrease after loading and unloading confiningpressure. The permeability of samples gradually decreases with the loading confining pressure,and the permeability of the sample gradually increases with the unloading confining pressure. Thepermeability of coal samples increases volatility with the increase of axial strain, and the fittedsample permeability and effective stress are subject to the ExpDec1 function distribution.

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Coal Anisotropic Sorption and Permeability: An Experimental Study

Cited by 8 publications

References 25 publications

The Relationship between Mining-Induced Stress and Coal Gas under an Optimized Support Scheme: A Case Study in the Guanyinshan Coal Mine, China

The Relationship between Mining-Induced Stress and Coal Gas under an Optimized Support Scheme: A Case Study in the Guanyinshan Coal Mine, China

Experiment and Modeling of Permeability under Different Impact Loads in a Structural Anisotropic Coal Body

Experimental Study on Mechanics and Permeability Properties of Water-Bearing Raw Coal Samples Under In-Situ Stress

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