Abutment pressure distribution pattern and size optimization of coal pillar under repeated mining: a case study

Du, Beiju; Yang, Jingxuan; Wu, Fengfeng

doi:10.1007/s12517-020-06281-y

Cited by 9 publications

(5 citation statements)

References 10 publications

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“…In the process of coal seam group mining, the concentrated stress formed by the residual section of a coal pillar in the foor of an upper coal seam has a great infuence on the safe mining of the lower coal seam [1]. Te presence of goaf in the upper segment makes the stress distribution of the surrounding rock more complicated than would otherwise have been the case [2]. A coal pillar may enter a residual state and the solid coal side of the next panel can become the main bearing body under the abutment load [3].…”

Section: Introductionmentioning

confidence: 99%

A Study on the Instability Mechanisms of Coal Pillars in Shallow Coal Seams Group Mining

Tie-lin

Wang

Liu

et al. 2023

Advances in Civil Engineering

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To explore the instability mechanisms of coal pillars in the upper coal during coal seam group mining in the Yulin area and hence to achieve safe and green mining of the lower coal seams, the engineering geological condition for no. 3−1, no. 4−2, and no. 5−2 coal seams in the north-second panel area of Hongliulin Coal Mine was investigated in this article. Using the combination of physical simulation, FLAC3D numerical calculation, and theoretical analysis, the instability mechanisms, the characteristics of the fracture structure, and fracture evolution between the coal pillars and the interval rocks were all studied. The results showed that a layout position existed that induced instability and subsidence of the coal pillars of the upper coal seam. The instability mechanism was such that the concentrated stress of the upper and lower coal pillars caused shear plastic damage in the interval rock along the direction of stress-transfer influence angle. The phenomenon of “inclined step beam” fracture structure, falling fracture zone, and severe mine pressure happened during seam group mining. Furthermore, the minimum center offset formula was put forward to study the instability of the upper coal pillars. This study provides a theoretical basis for a reasonable layout on how to position coal pillars for shallow coal seams group mining.

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Section: Introductionmentioning

confidence: 99%

A Study on the Instability Mechanisms of Coal Pillars in Shallow Coal Seams Group Mining

Tie-lin

Wang

Liu

et al. 2023

Advances in Civil Engineering

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“…The engineering application had important significance for the surrounding rock control of the large-span roadway in the stress concentration area. According to research experience, the peak of advanced abutment pressure often reaches 2-4 times the in situ stress [26,27]. Therefore, the superposition of triple advance pressure is at least five times the in situ stress, which greatly improves the difficulty of controlling the 23616 open-off cut roadway.…”

Section: Introductionmentioning

confidence: 99%

Mechanism and Application of Prestressed Yielding Support for Large-Span Roadway in Multistress Concentration Areas

Cao¹,

Zhang

Yang³

et al. 2023

Processes

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Close-distance multilayer coal mining is common. Under the condition of extremely close-distance coal seams, it is extremely difficult to control the surrounding rock of large-span open-off cut roadways in multistress concentration areas. Based on the engineering background of the 23616 open-off cut roadway in Chaili Coal Mine, this paper investigated the influence of upper close seam mining on the stress and deformation of the lower large-span roadway in detail. The control effect of a high-strength prestressed yielding bolt and cable was analyzed systematically. The support system stress was coordinated by the yielding member to avoid excessive stress on the local support structure and reduce the stress concentration of the surrounding rock. Before and after the upper coal mining, the stress changed mainly on the left and right sides, and the displacement changed mainly on the right side and roof. The maximum deformation of the roof and the right side and the left side at two engineering observation sections was 85 mm, 61 mm, 48 mm and 68 mm, 53 mm, 46 mm, respectively. The surrounding rock control effect was relatively ideal, which can meet the needs of roadway installation support.

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“…18 In recent years, many working faces adopting double-roadway arrangements have appeared in the western mining areas in China, which makes coal pillar abutment pressure complex under repeated mining. 19 In view of the stability and deformation characteristics of the mining roadway in the mining process of large mining height working faces, deep well working faces and fully mechanized cave working faces, the optimization of coal pillar and dynamic load mechanism are studied, and the asymmetric deformation mechanism and control of gob side roadway in fully mechanized cave mining are studied. [20][21][22] In summary, the research on the distribution law of abutment pressures of coal pillar and its size optimization has achieved remarkable results.…”

Section: Introductionmentioning

confidence: 99%

“…In view of the stratified fully mechanized mining face in extra‐thick coal seam, the instability mechanism, and control technology of coal pillar under the direct roof of superthick coal seam are studied by theoretical analysis and field to test 18 . In recent years, many working faces adopting double‐roadway arrangements have appeared in the western mining areas in China, which makes coal pillar abutment pressure complex under repeated mining 19 . In view of the stability and deformation characteristics of the mining roadway in the mining process of large mining height working faces, deep well working faces and fully mechanized cave working faces, the optimization of coal pillar and dynamic load mechanism are studied, and the asymmetric deformation mechanism and control of gob side roadway in fully mechanized cave mining are studied 20–22 …”

Section: Introductionmentioning

confidence: 99%

Analysis and control of the mechanism of coal pillar sloughing in the shallow buried thick coal seam

Zhang

Yang

et al. 2022

Energy Science & Engineering

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In northern Shaanxi province, the coal seam deposit conditions are generally characterized by large thickness and shallow depth of burial, the phenomenon of coal pillar sloughing is serious in the process of working face retrieval, which brings great potential danger to mine safety production. In this paper, by monitoring the stress and damage of the coal pillar in the field section, the stress changes and damage degree of the working face in different mine stages are determined. A new mechanical model of coal pillar in a thick coal seam is constructed and the stress changes and structural breakage law of each section are obtained, the stress transfers mechanism of overburden structure and the stress damage to coal pillar during the mining process of upper and lower section comprehensive mining working face is analyzed. The stress, microscopic damage, and the degree of sloughing in the coal pillar were significantly reduced by monitoring through the top plate hydraulic cracking pressure relief control program. The results of the study show that the extent of sloughing coal pillar and internal damage is closely related to the length of key block B of the masonry beam formed by the overlying rock layer and the position of the break line, by changing the orientation of the overlying masonry beam rock layer and the position and length of the tendency to break line, the sloughing coal pillar is effectively controlled and its stress and damage are reduced. We have achieved good results in control of the sloughing in the Hanjiawan coal mine and similar mines in northern Shaanxi.

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Abutment pressure distribution pattern and size optimization of coal pillar under repeated mining: a case study

Cited by 9 publications

References 10 publications

A Study on the Instability Mechanisms of Coal Pillars in Shallow Coal Seams Group Mining

A Study on the Instability Mechanisms of Coal Pillars in Shallow Coal Seams Group Mining

Mechanism and Application of Prestressed Yielding Support for Large-Span Roadway in Multistress Concentration Areas

Analysis and control of the mechanism of coal pillar sloughing in the shallow buried thick coal seam

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