Coal pillar’s breaking and fracture development mechanism and numerical simulation

Teng, Fei; Yu, Minggao; Chao, Jiangkun; Ma, Zhihui

doi:10.2298/tsci2203439t

Cited by 6 publications

(8 citation statements)

References 23 publications

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“…However, increasing the width of the sectional protection coal pillar will result in a waste of coal resources; once the width of the coal pillar is left unfavorable, it can also cause instability of the coal pillar group, posing a great safety hazard. 4 Adopting the method of strengthening roadway support will significantly increase the cost of roadway support. To solve the problem of severe manifestation of rock pressure when the lower coal seam working face passes through the coal pillar, it is generally adopted to strengthen roof management, including ensuring that the hydraulic support is tightly connected to the roof, ensuring that the support strength meets the regulations, and strictly prohibiting the occurrence of the empty roof.…”

Section: Introductionmentioning

confidence: 99%

“…Strengthening roadway support can also be used to reduce the deformation of the roadway, 2,3 such as using a combined support process of the bolt, anchor, steel shed, and single hydraulic props. However, increasing the width of the sectional protection coal pillar will result in a waste of coal resources; once the width of the coal pillar is left unfavorable, it can also cause instability of the coal pillar group, posing a great safety hazard 4 . Adopting the method of strengthening roadway support will significantly increase the cost of roadway support.…”

Section: Introductionmentioning

confidence: 99%

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Hydraulic fracturing method for relieving stress concentration in remaining coal pillar in overlying goaf

Shao,

Huang,

Zhao

et al. 2024

Energy Science & Engineering

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The stress concentration caused by the presence of the remaining coal pillar in the overlying goaf can easily cause large deformation of the roadway in the lower seam and other problems. To solve this problem, the reasons for stress concentration caused by the remaining coal pillar in the overlying goaf were analyzed. A hydraulic fracturing method for relieving stress concentration has been proposed. By using hydraulic fracturing technology to remove the hanging roof on both sides of the coal pillar and weaken the coal pillar system, high stress is transferred to the goaf. The degree of stress concentration in coal pillars and surrounding rock of roadway can be reduced by 47% and 26%, respectively. This method can also solve the stress concentration problem of the remaining ore pillar in the overlying goaf of the metal ore. This method has been applied in the coal mine. The deformation of the surrounding rock of the test roadway after hydraulic fracturing has been reduced by more than 60%.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Hydraulic fracturing method for relieving stress concentration in remaining coal pillar in overlying goaf

Shao,

Huang,

Zhao

et al. 2024

Energy Science & Engineering

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show abstract

“…Based on the simulation results, they divided the coal pillar into "step settlement zone", "crack compaction zone", and "reverse stress zone", and determined the zone threatened by high risk of CPSC. 23,24 Meanwhile, the goaf near the working face is also vulnerable to air leakage from the fragmented coal pillar. By means of a nonlinear seepage equation, Zhu theoretically analyzed the air leakage microcirculation in the goaf behind the working face, the coal pillar in the goaf, and the adjacent goaf.…”

Section: Introductionmentioning

confidence: 99%

“…Teng adopted FLAC 3D numerical simulation software to simulate the dynamic evolution characteristics of stress and displacement in the upper coal pillar. Based on the simulation results, they divided the coal pillar into “step settlement zone”, “crack compaction zone”, and “reverse stress zone”, and determined the zone threatened by high risk of CPSC. , …”

Section: Introductionmentioning

confidence: 99%

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Research on the Law of Coal Pillar Spontaneous Combustion and Fire Prevention and Control Technology

Liu,

Qi,

Luo

et al. 2024

ACS Omega

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In coal pillar fires, the fire source is hard to be detected and the adjacent goaf is extremely likely to be affected. Such fires would give rise to thermal and dynamic disasters in mines, further causing casualties and environmental disruption. In this study, with the coal pillar spontaneous combustion (CPSC) accident in Chahasu Coal Mine taken as the research object, the oxygen uptake and limit of oxygen concentration of CPSC were explored. Based on the research results, a similar model was constructed, where a control group was used to simulate the hazardous area of CPSC in a bid to investigate the law of CPSC. Moreover, the polymer colloid perfusion system was constructed and the drilling parameters and perfusion process parameters were determined, and practices concerning spontaneous fire control were carried out. Here are the conclusions: First, air leakage in the coal pillar may lead to coal spontaneous combustion due to the impact of rib spalling, threatening 2−6 m above the middle of the coal pillar at a shallow position. Second, coal pillar grouting, injecting polymer colloids for cooling, and coal pillar cement reinforcement prove to be effective ways to prevent CPSC fires and combat recombustion.

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Coupling support technique for coal roadway under double gobs in close coal seams

Wu,

Nan,

Chen

et al. 2024

Energy Science & Engineering

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In the process of lower coal roadway support under double gobs in close coal seams, there are problems such as the whole destruction of the lower coal seam and the intermediate strata, the thin roof of the lower coal roadway with the smaller support space, the upper rock of the lower coal roadway without anchor bearing layer, the roof falling, the anchor cable offing, and so on. On the basis of the engineering background of No. 11103 haulage roadway in Fenxi coal mine, the research methods of theoretical modeling analysis, numerical simulation analysis and field engineering test are comprehensively adopted. In this paper, the layout of the roadway with floor insertion in the lower coal seam, the distribution characteristics of surrounding rock deviatoric stress, the control principle of broken surrounding rock and the coupling support method of shed–cable–prop are systematically studied. The study shows that many measures are needed to ensure the stability of the surrounding rock in the strong mining roadway of the lower coal seam. The lower coal seam roadway section was modified from the original rectangular section to adopt an arched section to counteract the broken roof. The staggered position of the lower coal seam roadway layout was modified from the original coal roadway position to a coal–rock roadway, so as to avoid the area of high deviatoric stress in the coal pillar and the area of crushed coal body, and to leave an effective support space for the roof. The support scheme of the lower coal seam roadway was improved to use anchor cable and single prop to support the weak section of U‐type steel shed with local coupling, and realize unequal force coupling by adjusting the size of the force at different coupling points. In the field monitoring the deformation of the roadway is small, and the support effect is good.

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Coal pillar’s breaking and fracture development mechanism and numerical simulation

Cited by 6 publications

References 23 publications

Hydraulic fracturing method for relieving stress concentration in remaining coal pillar in overlying goaf

Hydraulic fracturing method for relieving stress concentration in remaining coal pillar in overlying goaf

Research on the Law of Coal Pillar Spontaneous Combustion and Fire Prevention and Control Technology

Coupling support technique for coal roadway under double gobs in close coal seams

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