Zoning Control Technology of Gob-Side Roadway Driving with Small Coal Pillar Facing Mining in a Special Isolated Island Working Face: A Case Study

Yang, Haibo; Zhang, Nong; Deng, Rijian; Guo, Yuxin

doi:10.3390/app112210744

Cited by 8 publications

(4 citation statements)

References 12 publications

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“…With the increasing demands of coal resources and the construction of resource-saving coal mines, the implementation of narrow coal pillars to arrange working faces has become a more popular choice of more mines [1][2][3]. However, large deformation and damage of the GSR has also become a large problem, plaguing safe production in mines, especially for close extra-thick coal seams.…”

Section: Introductionmentioning

confidence: 99%

Research on Deformation and Failure Law of the Gob-Side Roadway in Close Extra-Thick Coal Seams

Gao

et al. 2023

Sustainability

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To reveal the deformation and failure law of the gob-side roadway (GSR) and the main influencing factors in close extra-thick coal seams, the research methods of field monitoring, theoretical analysis, and numerical simulation are adopted in this paper. Field monitoring data shows that microseismic events occur and accumulate frequently in the surrounding rock and some overlying key layers of the GSR. Large deformation is experienced in the middle part of roadway near the solid coal side, the middle and upper parts of the roadway near the coal pillar side, and the roadway floor. The overlying strata of the GSR are fractured to form a composite structure as “low-level cantilever beam and high-level masonry beam”. The coal pillar is squeezed and effected by the composite beam structure and the rotation moment M, causing serious bulge in middle and upper part of the coal pillar side. The stability of the solid coal side of the roadway is affected by the stress transferred from gangue contact point. Numerical simulation shows that the immediate roof and key layer breakage are induced by the mining of the 30,501 working face. Shear and tension failures happen in the GSR due to overburden subsidence and rotary extrusion. The stress and displacement at the middle and upper of the roadway on the coal pillar side are larger than the other area. Compared with the solid coal side, the coal on the coal pillar side is obviously more fractured, with a lower bearing capacity. The peak stress in the coal pillar shows up 2 m away from the roadway, which is close to the length of bolt support. The mining-induced stress and the stress transferred from gangue contact point are the direct reasons for solid coal bulge beside the roadway. The peak stress on the solid coal side is located 7 m away from the roadway, at the gangue contact point where overburden fractures. The overburden strata loads and the transferred stress near the gangue contact point are transferred from the sides to the roadway floor. Their coupling effect with the in situ horizontal stress acts as the force source for the plastic floor heave.

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Section: Introductionmentioning

confidence: 99%

Research on Deformation and Failure Law of the Gob-Side Roadway in Close Extra-Thick Coal Seams

Gao

et al. 2023

Sustainability

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“…Wang et al [18] found that when the roadway was located within the fracture line of the main roof, the deformation was mainly affected by the roof rotation, and when it was located outside the fracture line, the deformation was mainly affected by lateral stress. Han et al [19] believed that the deformation characteristics of the gob-side roadway are divided into the heading face mining zone, the mining influenced zone, and the mining stability zone.…”

Section: Introductionmentioning

confidence: 99%

Study on the Surrounding Rock Deformation Laws of Facing-Mining Roadway and the Reasonable Space–Time Relationship of Hydraulic Fracturing

Liu

Bian

et al. 2023

Processes

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The mining confrontation caused by a super-long working face is an important factor that leads to difficulties in the control of surrounding rock in facing-mining roadways. To address this issue, this study takes the 18106 working face of Xiegou Coal Mine as the engineering background. First, deformation characteristics of the surrounding rock in two stages of roadway mining are explored, and the principle of determining the time for fracturing construction is presented. Additionally, the influence of fracturing space position on the control effect of the roadway’s surrounding rock is examined. Results show that the roadway which is influenced by adjacent working face mining has obvious asymmetric deformation, and the order of deformation is as follows: pillar side > roof > coal side > floor. The roof activity in goaf is the key factor of roadway deformation, and the proportion of deformation is 60%, followed by the influence of advance stress, accounting for 38%. After fracturing, with the increase in fracturing height, the deformation of the surrounding rock decreases, and the decrease in deformation of the roof and two sides also reduces, while the decrease in deformation of the floor remains relatively stable. The reasonable fracturing height is 10 m, and the reasonable fracturing construction time is 17 days before the confrontation between the working face and the roadway. Field practice suggests that there are effective cracks in the roof after fracturing, and the deformation of the surrounding rock in facing-mining roadways is reduced by more than 60% compared to that without fracturing. Hydraulic fracturing is significant for controlling the deformation of the surrounding rock in facing-mining roadways.

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“…Jiang [23] presented an approach for evaluating, designing, and optimizing EDG and yield pillar based on the results of numerical simulations and field practice. Han et al [24][25][26] considered special geological situations to drive an entry along the gob, such as in an isolated island working face, in a deep soft-broken coal seam, or in a working face adopting roadway side sealing technology. The targeted control techniques of the surrounding rock were proposed and successfully applied in the field practices.…”

Section: Introductionmentioning

confidence: 99%

Control Techniques for Gob-Side Entry Driving in an Extra-Thick Coal Seam with the Influence of Upper Residual Coal Pillar: A Case Study

Xie

Guo

2022

Energies

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In multi-seam mining, the residual coal pillar (RCP) in the upper gob has an important influence on the layout of the roadway in the lower coal seam. At present, few papers have studied the characteristics of the surrounding rock of gob-side entry driving (GED) with different coal pillar widths under the influence of RCP. This research contributes to improving the recovery rate of the extra-thick coal seam under this condition. The main research contents were as follows: (1) The mechanical parameters of the rock and coal mass were obtained using laboratory experiments coupled with Roclab software. These parameters were substituted into the established main roof structure mechanics model to derive the breakage position of the main roof with the influence of RCP, and the rationality of the calculation results was verified by borehole-scoping. (2) Based on numerical simulation, the evolution laws of the lateral abutment stress in the lower working face at different relative distances to the RCP were studied. FLAC3D was used to study the whole space-time evolution law of deviatoric stress and plastic zone of GED during driving and retreating periods with various coal pillar widths under the influence of RCP. (3) The plasticization factor P was introduced to quantify the evolution of the plastic zone in different subdivisions of the roadway surrounding rock, so as to better evaluate the bearing performance of the surrounding rock, which enabled a more effective determination of the reasonable coal pillar width. The field application results showed that it was feasible to set up the gob-side entry with an 8 m coal pillar below the RCP. The targeted support techniques with an 8 m coal pillar could effectively control the surrounding rock deformation.

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Zoning Control Technology of Gob-Side Roadway Driving with Small Coal Pillar Facing Mining in a Special Isolated Island Working Face: A Case Study

Cited by 8 publications

References 12 publications

Research on Deformation and Failure Law of the Gob-Side Roadway in Close Extra-Thick Coal Seams

Research on Deformation and Failure Law of the Gob-Side Roadway in Close Extra-Thick Coal Seams

Study on the Surrounding Rock Deformation Laws of Facing-Mining Roadway and the Reasonable Space–Time Relationship of Hydraulic Fracturing

Control Techniques for Gob-Side Entry Driving in an Extra-Thick Coal Seam with the Influence of Upper Residual Coal Pillar: A Case Study

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