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Research and Application of Different Coal Wall Spalling Forms

Received: Sep. 21, 2023    Accepted: Oct. 23, 2023    Published: Nov. 09, 2023
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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.

DOI 10.11648/j.earth.20231206.11
Published in Earth Sciences ( Volume 12, Issue 6, December 2023 )
Page(s) 188-197
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This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.

Copyright

Copyright © The Author(s), 2024. Published by Science Publishing Group

Keywords

Rib Spalling, Coal Wall Rupture Angle, Poisson's Ratio, Shear Failure, Tension Failure

References
[1] WANG JH. Mechanism of the rib spalling and the controlling in the very soft coal seam. Journal of China Coal Society, 2007, 32(8): 785-788.
[2] Fang XQ, He J, Li HC. A study of the rib mechanism in soft coal and its control at a fully-mechanized top-coal caving face [J]. Journal of China University of Mining & Technology, 2009, 38(5): 640-644.
[3] Yuan Y, Tu SH, MA XT, et al. Coal wall stability of fully mechanizing mining face with great mining height in “three-soft” coal seam and its control technology [J]. Journal of Mining & Safety Engineering, 2012, 29(1): 21-25.
[4] Wu YP, Lang D, Xie P. Mechanism of disaster due to rib spalling at fully-mechanized top coal caving face in soft steeply dipping seam [J]. Journal of China Coal Society, 2016, 41(8): 1878-1884.
[5] Yin XW, Yan SH, An Y. Characters of the rib spalling in fully mechanized caving face with great mining height [J]. Journal of Mining & Safety Engineering, 2008, 25(2): 222-225.
[6] Ning Y. Mechanism and control technique of the rib spalling in fully mechanized mining face with great mining height [J]. Journal of China Coal Society, 2009, 34(1): 50-52.
[7] Yang JX, Liu CY, Wu FF. The research on the coal wall stability mechanism in larger height coal seam with a stratum of gangue [J]. Journal of Mining & Safety Engineering, 2013, 30(6): 856-862.
[8] Huang QX, Liu JH. Vertical slice model for coal wall spalling of large mining height longwall face in shallow seam [J]. Journal of Mining & Safety Engineering, 2015, 32(2): 187-191.
[9] Zhang HW, Fu X, Shen YZ. Study on rib spalling mechanism and spalling depth in large mining height fully-mechanized face, in NajAziz and Bob Kininmonth [C]. Proceedings of the 2016 Coal Operators' Conference, Mining Engineering, University of Wollongong, 2019: 204-212.
[10] Wu H, Song XM. Theoretical analysis on coal wall stability of fully mechanized 8.5m high cutting longwall mining face [J]. Coal Science and Technology, 2015, 43(3): 22-25.
[11] Di S, Wang JR, Song GJ. Study on rib spalling characteristics of 8.5m height fully mechanized mining face. Coal Science and Technology, 2017, 45(9): 97-102.
[12] Xu YJ. Coal wall spalling mechanism studying and it’s prevention method [J]. Coal Mining Technology, 2017, 22(1): 41-46.
[13] Song ZQ, Liang SK, Tang JQ, et al. Study on the influencing factors of coal wall rib spalling in fully mechanized working face [J]: Journal of Hunan University of Science & Technology (Natural Science Edition): 2011, 26(1): 1~4.
[14] Wang JH, Wang ZH, Kong DZ. Failure and prevention mechanism of coal wall in hard coal seam [J]. Journal of China Coal Society, 2015, 40(10): 2243-2250.
[15] Zhang JH, Li MZ, Yang ZK, et al. Mechanism of coal wall spalling in super high fully mechanized face and its multi-dimensional protection measures [J]. Journal of Mining & Safety Engineering, 2021, 38(3): 487-495.
[16] XU YX, Wang GF, Li MZ, et al. Investigation on coal face slabbed spalling features and reasonable control at the longwall face with super large height and longwall top coal caving method [J]. Journal of China Coal Society, 2021, 36(5): 728.
[17] XU YX, Wang GF, Li MZ, et al. Mechanism of slabbed spalling failure of the coal face in fully mechanized caving face with super large cutting height [J]. Journal of Mining & Safety Engineering, 2021, 38(1): 19-30.
[18] Yan JH. Analysis on interaction relationship between initial support load of powered support and surrounding rock in fully-mechanized coal mining face [J]. Coal Science and Technology, 2014, 42(4): 12-15.
[19] Zhang YL, Liu JF, Pang YH, et al. Effect analysis of prevention rib spalling system in hydraulic support [J]. Journal of China Coal Society: 2011, 36(4): 691-695.
[20] Wang GF, Pang YH, Liu JF. Determination and influence of cutting height of coal by top coal caving method with great mining height in extra thick coal seam [J]. Journal of China Coal Society: 2012, 37(11): 1777-1782.
[21] Chang JC, Xie GX, Zhang XH. Analysis of rib spalling mechanism of fully-mechanized top-coal caving face with great mining height in extra-thick coal seam [J]. Rock and Soil Mechanics, 2015, 36(3): 803-808.
[22] Xu YJ. Study on parameter optimization and coupling relation between surrounding rock and 2-leg powered support [D]. Coal Science Research Institute, 2013.
[23] Xu YJ. Research and application of coal wall limit stability height based on wedge model [J]. Chinese Journal of Rock Mechanics and Engineering, 2022, 41(Sup. 2): 3240-3248.
[24] Wu XM, Lei ZY, Wen J, et al. Experiment on prevention and control of coal wall spalling in three soft coal seam working face [J]. Coal Science and Technology, 2022, 50(9): 20-29.
[25] Li ZJ, Ji Z. Causes of rib spalling and the prevention measures in 8. 8m super-high mining face [J]. Coal Engineering, 2021, 53(11): 30-35.
[26] Xu YJ, WANG Guofa, ZHANG Jinhu, et al. Theory and application of supporting stress fields of hydraulic powered support groups in fully mechanized mining face with large mining height based on elastic supporting beam model [J]. Chinese Journal of Rock Mechanics and Engineering, 2018, 37(5): 1226-1236.
[27] Wang GF, Zhang JH, Xu YJ, et al. Supporting stress characteristics and zonal cooperative control technology of long mining face in deep thick coal seam [J]. Journal of China Coal Society, 2021, 46(3): 763-773.
[28] Qian MG. Mining pressure and strata control [M]. Coal Industry Press: Beijing, 1986: 48.
[29] Jiang FX, Liu JH, Wang P. Model of coal burst and instability based on Druker-Prager yield criterion [J]. Journal of China Coal Society, 2011, 36(5): 728.
[30] Sun Y, Li G, Zhang N, et al. Development of ensemble learning models to evaluate the strength of coal-grout materials [J]. International Journal of Mining Science and Technology, 2020, 31(2): 153-162.
[31] Wang JC, Wang ZH. Systematic principles of surrounding rock control in longwall mining within thick coal seams [J]. International Journal of Mining Science and Technology, 2019, 29(1): 64-70.
[32] Shen ZJ. Breakage mechanics and double-medium model for geological material [J]. Hydro-Science and Engineering, 2002, (4): 1-6.
[33] Shen ZJ, Liu EL, Chen TL. Generalized stress-strain relationship of binary medium model for geological materials [J]. Chinese Journal of Geotechnical Engineering, 2005, 27(5): 489-494.
[34] Liu S, Yang K, Tang CN. Mechanism and integrated control of “Rib Spalling: roof collapse-support instability” Hazard Chains in steeply dipping soft coal seams [J]. Advances in Materials Science and Engineering, 2021, 5: 4.
[35] J. Galvin. Coal burst on longwall B2 face at Austar coal mine on 19 August 2016 [A]. Mine safety, NSW Department of Industry: New South Wales, 2016: 6.
[36] John Cornwell. The Colliery photographs of John Cornwell. https://museum.wales/articles/ 1035/ The-Colliery-photographs-of-John-Cornwell.
[37] Li G, Li Z, Du F, et al. Study on the failure characteristics of coal wall spalling in thick coal seam with gangue [J]. Advances in Civil Engineering, 2020, (2): 1-10.
[38] Bai QS, Zhang XQ, Zhang C, et al. Numerical modelling on brittle failure of coal wall in longwall face-a case study [J]. Arabian Journal of Geosciences, 2014, 7(12): 5067-5080.
[39] Sun GZ, Sun Y. Principle of rock mechanics [J]. Science Press: Beijing, 2011: 71-76.
[40] An M, Yu MH, Wu X, et al. Generalized twin shear stress yield criterion in rock mechanics [J]. Rock and Soil Mechanics, 1991, 12(10): 17-26.
[41] Xie QD, He J, Liu J, et al. Unified twin shear strength theory for calculation of earth pressure [J]. 2003, 25(3): 344.
[42] Mark Colwell, Christopher Mark. Analysis and Design of Rib Support (ADRS) a rib support design mythology for Australian collieries [J]. Proceedings of the 24th International Conference on Ground Control in Mining. Morgantown, WV: West Virginia University, 2005: 12-22.
[43] Xu YX. Study on Structure Coupling between Hydraulic Roof Support and Surrounding Rock in Extra-thick and Hard Coal Seam with Super-large Mining Height and Longwall Top Coal Caving Method [D]. China Coal Research Institute, 2020.
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    Xu, Y., Du, Y., Zhang, K., Pang, X., Xu, Y. (2023). Research and Application of Different Coal Wall Spalling Forms. Earth Sciences, 12(6), 188-197. https://doi.org/10.11648/j.earth.20231206.11

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    ACS Style

    Xu, Y.; Du, Y.; Zhang, K.; Pang, X.; Xu, Y. Research and Application of Different Coal Wall Spalling Forms. Earth Sci. 2023, 12(6), 188-197. doi: 10.11648/j.earth.20231206.11

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    AMA Style

    Xu Y, Du Y, Zhang K, Pang X, Xu Y. Research and Application of Different Coal Wall Spalling Forms. Earth Sci. 2023;12(6):188-197. doi: 10.11648/j.earth.20231206.11

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  • @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://download.sciencepg.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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Author Information
  • Coal Mining Research Branch, China Coal Research Institute, Beijing, China; Coal Mining Research Institute Co. Ltd of CCTEG, Beijing, China

  • Coal Mining Research Branch, China Coal Research Institute, Beijing, China; Coal Mining Research Institute Co. Ltd of CCTEG, Beijing, China

  • Shandong Provincial Key Laboratory of Robotics and Intelligent Technology, Shandong University of Science and Technology, Qingdao, China

  • Coal Mining Research Branch, China Coal Research Institute, Beijing, China; Coal Mining Research Institute Co. Ltd of CCTEG, Beijing, China

  • Coal Mining Research Branch, China Coal Research Institute, Beijing, China; Coal Mining Research Institute Co. Ltd of CCTEG, Beijing, China

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