@article{10.11648/j.earth.20231206.11,
  author = {Yajun Xu and Yibo Du and Kun Zhang and Xiaoliang Pang and Yongxiang Xu},
  title = {Research and Application of Different Coal Wall Spalling Forms},
  journal = {Earth Sciences},
  volume = {12},
  number = {6},
  pages = {188-197},
  doi = {10.11648/j.earth.20231206.11},
  url = {https://doi.org/10.11648/j.earth.20231206.11},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.earth.20231206.11},
  abstract = {Coal wall spalling is a key technical problem for surrounding rock control in fully mechanized mining face. For many years, coal wall spalling has mainly been studied through laboratory experiments based on coal samples, and in recent years, numerical simulation software has been used for simulation analysis. Theoretical research is mainly based on a two-dimensional coal wall model. At present, the academic circle divides the coal wall spalling into two forms: shear and tensile spalling. However, the mechanism of coal wall spalling was not clear, and it is difficult to describe the causes of different spalling forms in different coal seam conditions. To solve the above problems, according to the characteristics of coal wall spalling, a three-dimensional simplified model of rib spalling is derived based on the plane spline stress balance condition. Based on this, fully considering the influence of overburden pressure, coal rock interface cohesion, and internal friction angle on shear stress and internal shear stress of coal, the stress balance equation of the coal wall spalling body based on a three-dimensional wedge model is established, and the calculation formula of coal wall slope fracture angle is derived combined with the shear failure characteristics of soft coal and tensile failure characteristics of hard coal. The formula of coal wall fracture angle integrates parameters such as coal seam depth, dynamic pressure coefficient, coal rock interface cohesion and internal friction angle, Poisson's ratio, coal cohesion, and internal friction angle. The shear failure of soft coal and the tensile failure of hard coal are characterized by a unified formula. The effects of coal seam depth, coal rock interface cohesion and internal friction angle, coal cohesion and internal friction angle, Poisson's ratio, and other parameters on coal wall fracture angle are studied. The mechanism of soft coal seam, medium hard coal seam, and hard coal seam rib spalling is analyzed, and the characteristics of shear sliding failure of soft coal seam, block failure of medium hard coal seam and plate slope of hard coal seam are well explained. Taking the fully mechanized face with large mining height in the hard coal seam of Jinjitan coal mine as an example, the fracture angle of the coal seam is calculated, and the characteristics of coal wall spalling like plate shape are well explained, which provides a practical theoretical analysis method for the final solution of this problem.
},
 year = {2023}
}

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TY  - JOUR
T1  - Research and Application of Different Coal Wall Spalling Forms
AU  - Yajun Xu
AU  - Yibo Du
AU  - Kun Zhang
AU  - Xiaoliang Pang
AU  - Yongxiang Xu
Y1  - 2023/11/09
PY  - 2023
N1  - https://doi.org/10.11648/j.earth.20231206.11
DO  - 10.11648/j.earth.20231206.11
T2  - Earth Sciences
JF  - Earth Sciences
JO  - Earth Sciences
SP  - 188
EP  - 197
PB  - Science Publishing Group
SN  - 2328-5982
UR  - https://doi.org/10.11648/j.earth.20231206.11
AB  - Coal wall spalling is a key technical problem for surrounding rock control in fully mechanized mining face. For many years, coal wall spalling has mainly been studied through laboratory experiments based on coal samples, and in recent years, numerical simulation software has been used for simulation analysis. Theoretical research is mainly based on a two-dimensional coal wall model. At present, the academic circle divides the coal wall spalling into two forms: shear and tensile spalling. However, the mechanism of coal wall spalling was not clear, and it is difficult to describe the causes of different spalling forms in different coal seam conditions. To solve the above problems, according to the characteristics of coal wall spalling, a three-dimensional simplified model of rib spalling is derived based on the plane spline stress balance condition. Based on this, fully considering the influence of overburden pressure, coal rock interface cohesion, and internal friction angle on shear stress and internal shear stress of coal, the stress balance equation of the coal wall spalling body based on a three-dimensional wedge model is established, and the calculation formula of coal wall slope fracture angle is derived combined with the shear failure characteristics of soft coal and tensile failure characteristics of hard coal. The formula of coal wall fracture angle integrates parameters such as coal seam depth, dynamic pressure coefficient, coal rock interface cohesion and internal friction angle, Poisson's ratio, coal cohesion, and internal friction angle. The shear failure of soft coal and the tensile failure of hard coal are characterized by a unified formula. The effects of coal seam depth, coal rock interface cohesion and internal friction angle, coal cohesion and internal friction angle, Poisson's ratio, and other parameters on coal wall fracture angle are studied. The mechanism of soft coal seam, medium hard coal seam, and hard coal seam rib spalling is analyzed, and the characteristics of shear sliding failure of soft coal seam, block failure of medium hard coal seam and plate slope of hard coal seam are well explained. Taking the fully mechanized face with large mining height in the hard coal seam of Jinjitan coal mine as an example, the fracture angle of the coal seam is calculated, and the characteristics of coal wall spalling like plate shape are well explained, which provides a practical theoretical analysis method for the final solution of this problem.

VL  - 12
IS  - 6
ER  - 

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