Study on the Migration Law of Overlying Rock in the Upward Layered Continuous Mining Face of Thick Coal Seam with Paste Backfill Mining

Wen, Xinglin; Ge, Zhengchen; Zhang, Fuyu

doi:10.1155/2022/7297477

Cited by 5 publications

(2 citation statements)

References 6 publications

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“…The average unit weight of rock was 25 KN/m 3 . The gas pressure was taken as 0.5 MPa [30,31]. The mechanical parameters used in the model are shown in Table 1.…”

Section: Establishment Of a Three-dimensional Numerical Modelmentioning

confidence: 99%

Study on the Spatiotemporal Dynamic Evolution Law of a Deep Thick Hard Roof and Coal Seam

Zhang,

Dai,

Sun

et al. 2023

Processes

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Underground mining in coal mines causes strong disturbance to geological structures and releases a large amount of elastic strain energy. When the roof is a hard and thick rock layer, it is easy to cause dynamic disasters such as rock burst. To analyze the impact of a deep thick and hard roof fracture on the safe mining of thick coal seams, this paper studied the dynamic evolution process of the stress field, displacement field, energy field, and plastic zone of the coal seam and overlying strata during the mining process using FLAC3D numerical simulation. The results show that as the working face continues to be mined, the concentrated stress in the overlying strata first increases and then decreases, and the support pressure in front of the working face continues to increase. When it advances to 100 m, collapse occurs, and the stress increases sharply; the bottom plate undergoes plastic failure, resulting in floor heave. The overlying strata mass in the top plate exhibits downward vertical displacement, while the rock mass in the bottom plate exhibits upward vertical displacement, with a maximum subsidence of 4.51 m; energy concentration areas are generated around the working face roadway, forming an inverted “U” shape. When collapse occurs, the energy density decreases slightly; the direction of the plastic zone changes from “saddle shaped” to complete failure of the upper rock layer, and the overlying strata is mainly shear failure, which expands with the increase in mining distance. The research results have important practical significance for guiding the safe mining of deep thick and hard roof working faces.

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“…The average unit weight of rock was 25 KN/m 3 . The gas pressure was taken as 0.5 MPa [30,31]. The mechanical parameters used in the model are shown in Table 1.…”

Section: Establishment Of a Three-dimensional Numerical Modelmentioning

confidence: 99%

Study on the Spatiotemporal Dynamic Evolution Law of a Deep Thick Hard Roof and Coal Seam

Zhang,

Dai,

Sun

et al. 2023

Processes

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“…Tu Shihao et al [18], in response to the problem of large impact pressure on the overlying rocks, adopted the control measures of blasting the residual coal column to release the top and unload the pressure, injecting sand into the coal room and reasonably controlling the mining height to achieve the safe and efficient production of the working face in response to the problem that the mining under the room mining area of the working face of the shallowly buried coal seam is prone to unload the mine pressure and even the mine pressure. Xu Jingmin et al [19] proposed the control measures of using blasting or other means to weaken the coal pillar of room Processes 2023, 11, 1320 3 of 15 mining in advance, slow down the advancing speed of the working face, and slurry filling in the coal pillar area of room mining in view of the vulnerability of mining under the room mining area of the shallowly buried coal seam, and other scholars put forward the control measures of optimizing the position of back mining tunnel under the near coal seam mining area [20][21][22][23], and joint and coordinated mining of near coal seam group [24][25][26][27], etc. The technical measures for mine pressure control are proposed.…”

Section: Introductionmentioning

confidence: 99%

Study on the Mechanism and Control of Strong Rock Pressure in Thick Coal Seam Mining under the Goaf of Very Close Multiple Coal Seams

Feng

Wang

Wang³

et al. 2023

Processes

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With the increasing proportion of close-distance coal seam mining in China, the problem of strong mining pressure during the mining of close-distance coal seams is becoming more and more severe. This article focuses on the complex stress environment and severe mining pressure encountered in the mining of thick coal seams under the multi-coal-seam goaf of Zhunnan Coal Mine. By using research methods, such as similar material simulation, theoretical analysis, and numerical simulation, it studies in depth the instability characteristics of the overlying rock structure of the W1701 working face, the inducing factors and mechanisms of strong mining pressure during the mining process, and control measures. The results show that the roof structure of the W1701 working face can be divided into “high-level key layer (hard rock)–giant thick soft and weak rock group–low-level key layer (hard rock)”, and the law of mining pressure manifestation presents a small cycle formed by the instability of “masonry beam” structure and a main large cycle formed by the periodic penetration and step-down of the giant thick soft and weak rock group, with the load on the support during the large cycle up to 5.4 times the rated working resistance. In addition, this article proposes the strategy of using layered mining to control the manifestation of strong mining pressure under the “hard sandwiched soft” overlying rock condition of the Zhunnan Coal Mine, optimizes the thickness of the layered mining of the thick coal seam, and finally, determines the upper layer thickness of 2.8 m and the lower layer thickness of 4 m, inducing the giant thick soft and weak rock formation to undergo incremental damage and releasing the fracture energy incrementally, effectively controlling the manifestation threat of strong mining pressure in the mining of thick coal seams under the close-distance coal seam goaf. As the proportion of close-range coal seam mining increases in China, the problem of strong mining pressure during the mining of close-range coal seams becomes more severe. This article focuses on the complex stress environment and severe mining pressure in the mining of thick coal seams under multiple mined-out areas in the Zhunnan coal mine. Similar material simulation, theoretical analysis, and numerical simulation methods were used to conduct in-depth research on the unstable characteristics of the overlying rock structure of the W1701 working face, the causes and mechanisms of strong mining pressure during the mining process, and control measures. The results show that the roof structure of the W1701 working face can be divided into “high-level key layer (hard rock)–thick soft weak rock group–low-level key layer (hard rock).” The law of mining pressure manifestation presents small cycles of instability formed by “block beams” and main cycles of pressure formed by vertically cracked periodic penetration and step sinking of the thick soft weak rock group. Moreover, during the main cycle of pressure, the load-bearing capacity of the support is up to 5.4 times the rated working resistance. Furthermore, it is proposed to use hierarchical mining to control the manifestation of strong mining pressure in the “hard-inlaid soft” overlying rock condition of the Zhunnan coal mine and optimize the thickness of layered mining of thick coal seams. Ultimately, the upper layer thickness was determined as 2.8 m; the lower layer thickness was determined as 4 m, and the layered mining induced the thick soft weak rock group to undergo gradual damage and energy release, effectively controlling the threat of severe mining pressure during the mining of thick coal seams under the close-range coal seam mining.

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Deformation mechanism and control technology of gob-side roadway with continuous mining and continuous backfilling: a case study

Chen,

Wang,

Bai

et al. 2024

Geomatics, Natural Hazards and Risk

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Study on the Migration Law of Overlying Rock in the Upward Layered Continuous Mining Face of Thick Coal Seam with Paste Backfill Mining

Cited by 5 publications

References 6 publications

Study on the Spatiotemporal Dynamic Evolution Law of a Deep Thick Hard Roof and Coal Seam

Study on the Spatiotemporal Dynamic Evolution Law of a Deep Thick Hard Roof and Coal Seam

Study on the Mechanism and Control of Strong Rock Pressure in Thick Coal Seam Mining under the Goaf of Very Close Multiple Coal Seams

Deformation mechanism and control technology of gob-side roadway with continuous mining and continuous backfilling: a case study

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