Numerical Analysis of Support Designs Based on a Case Study of a Longwall Entry

  • Lishuai JiangEmail author
  • Peng Kong
  • Jiaming Shu
  • Kegong Fan
Original Paper


The stability of the entries of longwall panels is a major concern in underground coal mines. While panel entries have a short service life, they must be well supported to sustain the mining-induced loads during panel extraction. In this paper, a panel-wide numerical model was built with FLAC3D to examine a longwall panel entry with poor stability. The processes of entry development and panel retreat mining are simulated with three different entry support designs: the original design in the field and two newly proposed designs. The ground stability in each support condition was examined and compared in terms of ground deformation and extent of failure. A field test was then conducted to compare the three support designs. An instrumentation program was put in place in the field, and monitoring results were used to validate the numerical models. An optimal support design under the associated geological and geotechnical conditions was obtained. The underlying support mechanism was further analyzed with numerical modeling in the view of support-induced stress distribution in the surrounding rock mass. The results suggest that employing proper support with pre-tension generates a large area of support-induced stress in the surrounding rock mass, thereby improving the ground stability in terms of eliminating rock failure and limiting deformation. The results of this study contribute to the understanding of the role of pre-tensioned supports and can be utilized for support design and optimization under similar geological and geotechnical circumstances.


Longwall mining Numerical simulation Roadway stability Rock bolt support Support design 

List of Symbols


Bulk modulus


Shear modulus




Tensile strength


Friction angle


Residual cohesion


Plastic strain parameter at the residual strength



The research of this study was sponsored by the National Key R&D Program of China (2018YFC0604703), the National Natural Science Foundation of China (51704182, 51574155), the Natural Science Foundation of Shandong Province (ZR2017BEE050), the State Key Laboratory for GeoMechanics and Deep Underground Engineering (SKLGDUEK1725) and the Shandong University of Science and Technology. The field information from the study site was provided by the Zhaogu No. 2 coal mine, owned by Henan Energy & Chemical Industry Group Co., Ltd. The authors are grateful for their support.


  1. Barton N, Lien R, Lunde J (1974) Engineering classification of rock masses for the design of tunnel support. Rock Mech 6(4):189–236CrossRefGoogle Scholar
  2. Bobet A, Einstein HH (2011) Tunnel reinforcement with rockbolts. Tunn Undergr Sp Tech 26:100–123CrossRefGoogle Scholar
  3. Brown ET (1999) The evolution of support and reinforcement philosophy and practice for underground mining excavations. In: Proceedings of the International Symposium on Rock Support and Reinforcement Practice in Mining. Balkema, pp 3–18Google Scholar
  4. Carranza-Torres C (2009) Analytical and numerical study of the mechanics of rockbolt reinforcement around tunnels in rock masses. Rock Mech Rock Eng 42:175–228CrossRefGoogle Scholar
  5. Gao F, Stead D, Kang H (2015) Numerical simulation of squeezing failure in a coal mine roadway due to mining-induced stresses. Rock Mech Rock Eng 48:1635–1645CrossRefGoogle Scholar
  6. Ghazvinian A, Sarfarazi V, Schubert W, Blumel M (2012) A study of the failure mechanism of planar non-persistent open joints using PFC2D. Rock Mech Rock Eng 45:677–693CrossRefGoogle Scholar
  7. Hoek E, Carranza-Torres C, Corkum B (2002) Hoek-Brown failure criterion-2002 edition. Proc NARMS-Tac 1:267–273Google Scholar
  8. Jiang L, Sainoki A, Mitri HS, Ma N, Liu H et al (2016a) Influence of fracture-induced weakening on coal mine gateroad stability. Int J Rock Mech Min 88:307–317CrossRefGoogle Scholar
  9. Jiang L, Mitri HS, Ma N, Zhao X (2016b) Effect of foundation rigidity on stratified roadway roof stability in underground coal mines. Arab J Geosci 9:32CrossRefGoogle Scholar
  10. Jiang L, Zhang P, Chen L, Hao Z, Sainoki A et al (2017) Numerical approach for goaf-side entry layout and yield pillar design in fractured ground conditions. Rock Mech Rock Eng 50:3049–3071CrossRefGoogle Scholar
  11. Kang HP, Lin J, Fan MJ (2015) Investigation on support pattern of a coal mine roadway within soft rocks—a case study. Int J Coal Geol 140:31–40CrossRefGoogle Scholar
  12. Kang H, Li J, Yang J, Gao F (2017) Investigation on the influence of abutment pressure on the stability of rock bolt reinforced roof strata through physical and numerical modeling. Rock Mech Rock Eng 50(2):1–15CrossRefGoogle Scholar
  13. Li CC (2006) Rock support design based on the concept of pressure arch. Int J Rock Mech Min 43:1083–1090CrossRefGoogle Scholar
  14. Li YE (2018) Surrounding rock’s failure characteristic and rational location of floor gas drainaging roadway above the deep confined water. (Doctoral dissertation, China University of Mining and Technology (Beijing))Google Scholar
  15. Li Y, Wu W, Li B (2018) An analytical model for two-order asperity degradation of rock joints under constant normal stiffness conditions. Rock Mech Rock Eng 51(5):1431–1445CrossRefGoogle Scholar
  16. Ma NJ, Zhao ZQ, Feng JC (2013) Technology of butt long bolt on roadway supporting in difficult conditions. Coal Sci Technol 41(9):117–121Google Scholar
  17. Paul A, Singh AP, Loui P, Singh J, Khandelwal AK, M (2012) Validation of RMR-based support design using roof bolts by numerical modeling for underground coal mine of Monnet Ispat, Raigarh, India—a case study. Arab J Geosci 5:1435–1448CrossRefGoogle Scholar
  18. Peng SS (2008) Coal mine ground control, 3rd edn. Peng SS Publisher, Morgantown, WV, pp 229–237, 260–267Google Scholar
  19. Shen B (2014) Coal mine roadway stability in soft rock: a case study. Rock Mech Rock Eng 47:2225–2238CrossRefGoogle Scholar
  20. Shen WL, Bai JB, Li WF, Wang XY (2018) Prediction of relative displacement for entry roof with weak plane under the effect of mining abutment stress. Tunn Undergr Space Technol 71:309–317CrossRefGoogle Scholar
  21. Stankus J, Peng S (1996) A new concept for roof support. Coal Age Mag 9:2–6Google Scholar
  22. Wang P, Jiang L, Jiang J, Zheng P, Li W (2018) Strata behaviors and rock burst-inducing mechanism under the coupling effect of a hard, thick stratum and a normal fault. Int J Geomech. CrossRefGoogle Scholar
  23. Yang S, Chen M, Jing H, Chen K, Meng B (2017) A case study on large deformation failure mechanism of deep soft rock roadway in Xin’An coal mine, China. Eng Geol 217:89–101CrossRefGoogle Scholar
  24. Zhang K, Zhang G, Hou R, Wu Y, Zhou H (2015) Stress evolution in roadway rock bolts during mining in a fully mechanized longwall face, and an evaluation of rock bolt support design. Rock Mech Rock Eng 48:333–344CrossRefGoogle Scholar
  25. Zhao Y, Zhang N, Zheng X (2016) Experimental study of axial stress distribution and transfer along the bolt rods in an underground coal mine. Arab J Geosci 9:30CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Austria, part of Springer Nature 2019

Authors and Affiliations

  1. 1.State Key Laboratory of Mining Disaster Prevention and ControlShandong University of Science and TechnologyQingdaoChina
  2. 2.State Key Laboratory for GeoMechanics and Deep Underground EngineeringChina University of Mining and TechnologyBeijingChina
  3. 3.Department of Mining and Materials EngineeringMcGill UniversityMontrealCanada

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