Research on Mine Pressure Behave Law in Mining of Face under the Coal Pillar

Shi, Wendian; Liu, Hong Tao; Chen, Liang; Hou, Jia

doi:10.4028/www.scientific.net/amr.217-218.1721

Cited by 3 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In theoretical calculations, some necessary assumptions should be made to make the answer to the problem simple. The basic assumptions are [29][30][31] as follows:…”

Section: The Vertical Stress Distribution In the Coal Pillar Aftermentioning

confidence: 99%

Study on Reasonable Chain Pillar Size in a Thick Coal Seam

Zhang

Yue

2022

Geofluids

View full text Add to dashboard Cite

In order to solve the problem of low coal recovery rate caused by leaving large coal pillars in deep mines, the study determined the reasonable width of the section pillar, which based on the theory of coal pillar stress distribution, taking the 4102 headgate of Wenjiapo coal mine as the engineering background. Field monitoring and numerical simulation results show that the influence range of the lateral abutment pressure in the goaf is 50~56 m, and the abutment stress distribution in the coal pillar resembles a hump with two peaks of 38.9 MPa and 33.6 MPa, respectively. The positions of the double peaks are located at 12 m and 36 m in the coal pillar, respectively. In the range of “hump,” the section pillar vertical stress is in the original rock stress and is relatively stable. It can be regarded as an elastic zone in the coal pillar with strong bearing capacity, the coal in other areas have already undergone plastic yielding, and the bearing capacity has been reduced; the width of coal pillars in the determined section has been reduced from 46 m to 33 m, which is a reduction of 13 m. The research results have been applied in the 4106 headgate in the same mining area, and good test results have been obtained. The maximum subsidence of the roof-to-floor and rib-to-rib convergence is 286 mm and 150 mm, this indicates that its deformation was within the allowable limits, and the cross-section area was sufficient to satisfy the requirements.

show abstract

“…In theoretical calculations, some necessary assumptions should be made to make the answer to the problem simple. The basic assumptions are [29][30][31] as follows:…”

Section: The Vertical Stress Distribution In the Coal Pillar Aftermentioning

confidence: 99%

Study on Reasonable Chain Pillar Size in a Thick Coal Seam

Zhang

Yue

2022

Geofluids

View full text Add to dashboard Cite

show abstract

“…Therefore, studying the strength, deformation, fracture behavior, and stress distribution of rock mass is significant for understanding the fracture mechanism of rock mass and predicting the unstable failure of rock engineering [1][2][3][4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Stress distribution characteristics and crack propagation law of fractured hard rock influenced by opening degree

Jia,

Liu

2024

Preprint

View full text Add to dashboard Cite

Fracture opening degree and inclination angle are important factors affecting the crack evolution as well as the strength of the fractured rock body. To investigate the mechanical characteristics and cracking behavior of hard rock specimens under the combined influence of opening degree and inclination angle, we conducted uniaxial compression tests and numerical simulations on pre-cracked hard rock specimens. The study shows that as the crack dip angle increases, the initial crack position of hard rock specimens with prefabricated cracks of the same opening shifts from the short-axis end to the long-axis end. Additionally, when the crack opening is less than 1.5mm, the peak strength of the sample initially decreases and then increases with the increase of the crack dip angle. The peak strength of the sample increases as the crack dip angle increases when the crack opening is greater than 1.5mm. On the other hand, when the crack opening is less than 0.4mm, the peak crack initiation stress of the specimen first decreases and then increases with the increase of the crack inclination angle. When the crack opening is greater than 0.4mm, the crack initiation stress of the specimen gradually increases with the increase of the crack inclination angle. During the compression process, the closure of the crack surface weakens the concentration of compressive stress at the end of the prefabricated crack, thereby increasing the crack initiation stress of the shear crack. For instance, in the 30° inclined specimen, the crack initiation stress of the shear crack is 156.25MPa, 100.95MPa, and 92.02MPa when the openings are 0.2mm, 0.4mm, and 2mm, respectively. Based on the stress distribution law around the detected crack, it is evident that the tensile stress concentration area shifts from the middle of the crack to both ends as the crack dip angle increases. At a dip angle greater than 45°, the concentration area is entirely at the end of the crack. The crack opening has little effect on the crack initiation stress and peak strength of the sample when the prefabricated crack angle is greater than 45°. When the prefabricated crack angle is less than 45°, the opening of the crack significantly affects the stress at which the crack initiates and the peak strength of the sample. To describe the degree of closure of prefabricated cracks at different loading stages, we propose a transition model of 'fixed beam → fixed end and hinged end'. Our study reveals the crack propagation law and mechanical mechanism of prefabricated crack specimens with a certain opening under compressive load.

show abstract

“…After the upper coal seam is mined, the remaining coal pillar leads to stress concentration on the floor, especially when the distance of the coal seams is small to a certain degree. The stress concentration generates an obvious influence on the roof structure and the stress environment of the lower coal seam within the mining area and results in great difficulty in roadway maintenance, thereby seriously restricting the safety of the production process [2], [3], [4]. Yang [5] numerically simulated the bearing stress on the panel front and the stress characteristics on the gob floor in the mining process.…”

Section: Introductionmentioning

confidence: 99%

Influence of a Large Pillar on the Optimum Roadway Position in an Extremely Close Coal Seam

Li¹,

Zhang²,

zhuo³

et al. 2016

JESTR

View full text Add to dashboard Cite

Based on the mining practice in an extremely close coal seam, theoretical analysis was conducted on the vertical stress distribution of the floor strata under a large coal pillar. The vertical stress distribution regulation of a No. 5 coal seam was revealed. To obtain the optimum position of the roadway that bears the supporting pressure of a large coal pillar, numerical modeling was applied to analyze the relation among the stress distribution of the roadway surrounding the rock that bears the supporting pressure of a large coal pillar, the plastic zone distribution of the roadway surrounding the rock, the surrounding rock deformation, and the roadway layout position. The theoretical calculation results of the stress value, stress variation rate, and influencing range of the stress influencing angle showed that the reasonable malposition of the No. 5 coal seam roadway was an inner malposition of 4 m. The mining practice showed the following: the layout of No. 25301 panel belt roadway at the position of the inner malposition of 4 m was reasonable, the roadway support performance was favourable without deformation, and ground pressure was not obvious. The research achievement of this study is the provision of a reference for roadway layouts under similar conditions.

show abstract

Research on Mine Pressure Behave Law in Mining of Face under the Coal Pillar

Cited by 3 publications

References 0 publications

Study on Reasonable Chain Pillar Size in a Thick Coal Seam

Study on Reasonable Chain Pillar Size in a Thick Coal Seam

Stress distribution characteristics and crack propagation law of fractured hard rock influenced by opening degree

Influence of a Large Pillar on the Optimum Roadway Position in an Extremely Close Coal Seam

Contact Info

Product

Resources

About