Analytical study to estimate rib spalling extent and support requirements in thick seam mining

  • Wei-bin GuoEmail author
  • Chang-you Liu
  • Guo-wei Dong
  • Wen-yu Lv
Original Paper


In order to better understand the mechanism behind the poor stability of support and surrounding rocks at mechanized working faces with increased mining height (MWMH), a conceptual model of the support and rocks surrounding the MWMH, under different structural conditions of the main roof, is established in this study. On the basis of the mechanical model, the interaction among the coal wall, support and roof in MWMH is studied. The analytical analysis reveals that the coal wall and support interact more significantly in the MWMH than conventional approaches (e.g., conventional longwall mining). With the increase in the depth of rib spalling in coal wall, the support strength, needed to control the roof, increases linearly. While as the support strength increases, the depth of rib spalling in coal wall showed a hyperbolic-like decrease. Based on these results, the expression, which describes the relationship of the interaction between the rib spalling in coal wall and support strength in the MWMH, is proposed. Rib spalling is then controlled in real working face in a soft, thick coal seam. The field experiment demonstrates that the advanced long-hole hydrostatic pre-injection can control rib spalling in coal wall and guarantee the stability of support and surrounding rock, which enables a high-efficiency mining of the MWMH.


Mechanized mining Rib spalling Coal wall Rock-structure interaction Control technique 


Funding information

This work was supported and financed by the National Natural Science Foundation of China (Grant Nos. 51174192, 51604214, 51604212) and the Shaanxi Province Natural Science Foundation (Grant No. 2017JM5115).


  1. Bai QS, Tu SH, Zhang XG, Zhang C, Yuan Y (2014) Numerical modeling on brittle failure of coal wall in longwall face—a case study. Arab J Geosci 7:5067–5080CrossRefGoogle Scholar
  2. Beer F, Johnston E, Dewolf J, Mazurek D (2012) Mechanics of materials, 6th edn. McGraw-hill, New YorkGoogle Scholar
  3. Boresi A, Chong K, Lee J (2011) Elasticity in engineering mechanics, 3rd edn. Wiley, New YorkGoogle Scholar
  4. Das SK (2000) Observations and classification of roof strata behaviour over longwall coal mining panels in India. Int J Rock Mech Min Sci 37:585–597CrossRefGoogle Scholar
  5. Fang XQ, He J, Li HC (2009) A study of the rib fall mechanism in soft coal and its control at a fully-mechanized top-coal caving face. J Chin Uni Min Tech 38(5):640–644 (In Chinese)Google Scholar
  6. Gong PL (2006) Surrounding rock control theory and application study of the coal face with greater mining height. China Coal Industry Publishing House, Peking (In Chinese)Google Scholar
  7. Guo BH, Tu M (2003) Present condition of high mining height longwall mining techniques in China. Chin Min 12(10):41–43 (In Chinese)Google Scholar
  8. Guo WB, Wang HS, Dong GW, Li L, Huang YG (2017) A case study of effective support working resistance and roof support technology in thick seam fully-mechanized face mining with hard roof conditions. Sustainability 9(6):935CrossRefGoogle Scholar
  9. Hao YJ (2008) Equipment collocation application and analysis of fully mechanized large and high longwall caving face in Zhaozhuang mine. Coal Mine Mach 29(10):62–64 (In Chinese)Google Scholar
  10. He FL, Qian MG, Liu XF, Chen LW, Li CF (1997) Tilt characteristics and control conditions of high powered support. J Chin Uni Min Tech 26(4):20–24 (In Chinese)Google Scholar
  11. Hosseini N, Goshtasbi K, Oraee-Mirzamani B, Gholinejad M (2014) Calculation of periodic roof weighting interval in longwall mining using finite element method. Arab J Geosci 7:1951–1956CrossRefGoogle Scholar
  12. Hua XZ, Xie GX (2008) Coal wall spalling mechanism and control teehnology of fully mechanized high cutting longwall coal mining face. Coal Sci Tec 36(9):1–3,24 (In Chinese)Google Scholar
  13. Huang QX, Liu JH (2015) Vertical slice model for coal wall spalling of large mining height longwall face in shallow seam. J Min Saf Eng 32(2):187–191 (In Chinese)Google Scholar
  14. Ju JF, Xu JL (2013) Structural characteristics of key strata and strata behaviour of a fully mechanized longwall face with 7.0 m height chocks. Int J Rock Mech Min Sci 58:46–54CrossRefGoogle Scholar
  15. Ju JF, Xu JL, Wang QX (2011) Cantilever structure moving type of key strata and its influence on ground pressure in large mining height workface. J Chin Coal Soc 36(12):2115–2120 (In Chinese)Google Scholar
  16. Li JJ (2004) Practice and survey of press law of large mining height fully-mechanized face. J Nor Chin Inst Sci Tech 1(2):10–12 (In Chinese)Google Scholar
  17. Liu HW, Liu WF (2006) Study on influence factors of rib fall of coal wall in mining working face. Coal Tech 25(10):136–137 (In Chinese)Google Scholar
  18. Liu CY, Cao SG, Fang XQ (2003) The relationship between support and surrounding rock and technology of monitoring and control. Chin Uni Min Tech Press, Xuzhou (in Chinese)Google Scholar
  19. Mao DB, Kang LJ (2003) Longwall top coal caving mining with higher mining height and its feasibility. Chin Coal Min Tech 8(1):11–14,21 (In Chinese)Google Scholar
  20. Meng XR, Wang HP, Liu CH, Zhang Y (2009) Selection principle and development status of thick seam mining methods in China. Chin Coal Sci Tech 37(1):39–44 (In Chinese)Google Scholar
  21. Meng ZS, Zeng QL, Gao KD, Kong S, Liu P, Wang LR (2018) Failure analysis of super-large mining height powered support. Eng Fail Anal 92:378–391CrossRefGoogle Scholar
  22. Ning Y (2009) Mechanism and control technique of the rib spalling in fully mechanized mining face with great mining height. J Chin Coal Soc 2009(1):50–52 (In Chinese)Google Scholar
  23. Peng SS (2008) Coal Mine Ground Control, 3rd ed. Society for Mining Metallurgy, ChicagoGoogle Scholar
  24. Prusek S, Płonka M, Walentek A (2016) Applying the ground reaction curve concept to the assessment of shield support performance in longwall faces. Arab J Geosci 9:167CrossRefGoogle Scholar
  25. Sohu (2017) The first 8 m high working face was put into operation in Shendong Coal Group. (In Chinese)
  26. Song CY (2007) Mechanism and prevention measure of rib spalling in high caving face in Sihe coal mine. Coal Tech 26(4):52–54 (In Chinese)Google Scholar
  27. Tu SH, Yuan Y (2012) Theory and practice of fully-mechanized working face with great mining height in thick coal seam. Chin Uni Min Tech Press, Xuzhou (in Chinese)Google Scholar
  28. Wang K, Kang TH, Li HT, Han WM (2009) Study of control caving methods and reasonable hanging roof length on hard roof. Chin J Rock Mech Eng 28(11):2320–2327. (In Chinese)Google Scholar
  29. Wang JC, Yang SL, Kong DZ (2016) Failure mechanism and control technology of longwall coalface in large-cutting-height mining method. Int J Min Sci Tec 26:111–118CrossRefGoogle Scholar
  30. Yan SH, Yin XW, Xu HJ, Xu G, Liu QM, Yu L (2011) Roof structure of short cantilever-articulated rock beam and calculation of support resistance in full-mechanized face with large mining height. J Chin Coal Soc 36(11):1816–1820 (In Chinese)Google Scholar
  31. Yang SL, Yang FY, Li M (2010) Study on ground control and stability of coal wall of large mining height longwall face in shallow seam. Coal Eng 42(6):55–58 (In Chinese)Google Scholar
  32. Yang PJ, Liu CY, Wu FF (2012) Breakage and falling of a high coal wall in a thick mined seam. J Chin Uni Min Tec 41(3):371–377 (In Chinese)Google Scholar
  33. Yang JX, Liu CY, Wu FF, Yang Y (2013) The research on the coal wall stability mechanism in larger height coal seam with a stratum of gangue. J Min Saf Eng 30(6):856–862 (In Chinese)Google Scholar
  34. Yin XW, Yan SH, An Y (2008) Characters of the rib spalling in fully mechanized caving face with great mining height. J Min Saf Eng 25(2):222–225 (In Chinese)Google Scholar
  35. Yuan Y, Tu SH, Wu Q, Ma XT, Tu HS, Su LL (2011a) Mechanics of rib spalling of high coal walls under fully-mechanized mining. Min Sci Tec (China) 21:129–133Google Scholar
  36. Zhao HL, Yuan Y, Zhang L (2007) Strata behavior in fully mechanized top coal caving face of steep soft coal seams and its control. J Min Saf Eng 24(3):345–348. (In Chinese)Google Scholar
  37. Zhou DW (2009) Study on technology of soft coal seam rib spalling preventing by warter infusion with shallow holes. Master theses, Anhui Uni Sci Tec (In Chinese)Google Scholar
  38. Zhu T (2010) Study on the surrounding rock control theory and technology of soft seam in high mining height longwall face. Doctoral dissertation, Taiyuan Uni. Tec (In Chinese)Google Scholar
  39. Zhu GA, Dou LM, Wang CB, Li J, Cai W (2017) Numerical investigation of the evolution of overlying strata and distribution of static and dynamic loads in a deep island coal panel. Arab J Geosci 10:549CrossRefGoogle Scholar

Copyright information

© Saudi Society for Geosciences 2019

Authors and Affiliations

  • Wei-bin Guo
    • 1
    Email author
  • Chang-you Liu
    • 2
  • Guo-wei Dong
    • 3
  • Wen-yu Lv
    • 3
  1. 1.School of Energy Engineering, Key Laboratory of Western Mine Exploitation and Hazard Prevention with Ministry of Education, Safety Science and Engineering Post-Doctoral Research StationXi’an University of Science and TechnologyXi’anChina
  2. 2.School of Mines, Key Laboratory of Deep Coal Resource Mining, Ministry of Education of China, State Key Laboratory of Coal Resources and Mine SafetyChina University of Mining & TechnologyXuzhouChina
  3. 3.School of Energy Engineering, Key Laboratory of Western Mine Exploitation and Hazard Prevention with Ministry of EducationXi’an University of Science and TechnologyXi’anChina

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