Stability of goaf-side entry driving in 800-m-deep island longwall coal face in underground coal mine

  • Deyu Qian
  • Nong Zhang
  • Hideki Shimada
  • Cheng Wang
  • Takashi Sasaoka
  • Nianchao Zhang
Original Paper


Goaf-side entry driving in underground coal mines could greatly improve coal recovery rates. However, it becomes more difficult to maintain stability, especially in deep coal mines. Pillar width plays a pivotal role in the stability of goaf-side entry driving. To obtain a reasonable and appropriate narrow pillar width, theoretical calculations of the widths of mining-damaged zone and limit equilibrium zone in the pillar are derived according to limit equilibrium theory. Based on the stability issues of goaf-side entry driving in the first island longwall coal face (LCF) at a depth of 800 m below the surface in Guqiao Coal Mine in China, a numerical model is established by FLAC software to analyze the stability of the surrounding rock of goaf-side entry driving during excavation, using various coal pillar widths and support schemes. The results obtained from theoretical calculations, numerical simulation, and engineering practice indicate that an 8-m-wide coal pillar is relatively reasonable, appropriate, and feasible. Field measurements show that deformations of the surrounding rock could be efficiently controlled 31 days after the support schemes were implemented in goaf-side entry driving with an 8-m-wide narrow pillar along the adjacent goaf side with a compaction duration of 10 months. The mining influence range of the overlying LCF on the stability of goaf-side entry driving is found to be the area from 50 m ahead of the LCF to 70 m behind the LCF as it passes over the measurement point.


Island longwall coal face Goaf-side entry driving Coal pillar Surrounding rock Stability 



This study was sponsored by the Program for Changjiang Scholars and Innovative Research Team in University (IRT1084), the State Scholarship Fund from China Scholarship Council (201206420001), the National Natural Science Foundation of China (NSFC) (Grant No. 51574224 and No. 51574226) and Global Center of Excellence Program on Novel Carbon Resource Sciences launched by the Ministry of Education, Culture, Sports, Science and Technology (MEXT). The authors would like to express appreciation to Associate Professor Jiaguang Kan and Mr. Chengli Xiao at the China University of Mining and Technology and the staff at Guqiao Coal Mine for their support and assistance during the field measurements.


  1. Bai JB, Hou CJ, Huang HF (2004) Numerical simulation study on stability of narrow coal pillar of roadway driving along goaf. China J Rock Mech Eng 23(20):3475–3479 (in Chinese) Google Scholar
  2. China National Coal Association (CNCA) (2013) Forum on mining technology of 1000m-plus deep coalmines in China. Taian, China (in Chinese) Google Scholar
  3. Fan KG, Liang HG, Ma CS, Zang CW (2014) Non-harmonious deformation controlling of gob-side entry in thin coal seam under dynamic pressure. J Rock Mech Geotech Eng 6:269–274CrossRefGoogle Scholar
  4. Feng JC, Ma NJ, Zhao ZQ, Zhang H, Yu ZM (2014) Width of narrow coal pillar of roadway driving along goaf at large height mining face in deep mine. J Min Saf Eng 31(4):580–586 (in Chinese) Google Scholar
  5. Hou CJ, Ma NJ (1989) Stress in in-seam roadway sides and limit equilibrium zone. J China Coal Soc 4:21–29 (in Chinese) Google Scholar
  6. Hou CJ, Li XH (2001) Stability principle of big and small structures of rock surrounding roadway driven along goaf in fully mechanized top coal caving face. J China Coal Soc 26(1):1–7 (in Chinese) Google Scholar
  7. Hu GZ, Wang HT, Li XH, Fan XG, Yuan ZG (2009) Numerical simulation of protection range in exploiting the upper protective layer with a bow pseudo-incline technique. Min Sci Tech 19:58–64CrossRefGoogle Scholar
  8. Hua XZ, Liu S, Liu ZH, Zha WH, Li YF (2011) Research on strata pressure characteristic of gob-side entry driving in island mining face and its engineering application. Chin J Rock Mech Eng 30(8):1646–1651 (in Chinese) Google Scholar
  9. He MC, Xie HP, Peng SP, Jiang YD (2005) Study on rock mechanics in deep mining engineering. Chin J Rock Mech Eng 24(16):2803–2813 (in Chinese) Google Scholar
  10. Jacob O (1964) The origin of roof falls in starting faces with the caving system. Int J Rock Mech Min Sci 1:313–318CrossRefGoogle Scholar
  11. Liu HB, Cheng YP, Song JC, Shang ZJ, Wang L (2009) Pressure relief, gas drainage and deformation effects on an overlying coal seam induced by drilling an extra-thin protective coal seam. Min Sci Tech 19:724–729Google Scholar
  12. Liu HY, Cheng YP, Zhou HX, Wang F, Chen HD (2010) Fissure evolution and evaluation of pressure-relief gas drainage in the exploitation of super-remote protected seams. Min Sci Tech 20:178–782Google Scholar
  13. Liu QS, Liu KD (2012) Characteristics of in-situ stress field for deep levels in Huainan coal mine. Rock Soil Mech 33(7):2089–2096 (in Chinese) Google Scholar
  14. Qian D, Sasaoka T, Shimada H, Tsedendorj A, Wang C (2013) stability control of roadway in protected seam of deep high-gas multi-seams through ascending mining in China, Proceedings of International Symposium on Earth Science and Technology 2013, Fukuoka, Japan 154–160Google Scholar
  15. Qian D, Sasaoka T, Shimada H, Wahyudi S, Tsedendorj A, Wang C, Matsui K (2014) Analysis of coal pillar width and stability control of gob-side entry driving in deep island coal face. Proceedings of 2014 ISRM International Symposium and 8th Asian Rock Mechanics Symposium, Sapporo, Japan 1509–1518Google Scholar
  16. Qian MG, Shi PW (2003) Mining pressure and strata control. China University of Mining and Technology Press, Xuzhou (in Chinese) Google Scholar
  17. Shen B, King A, Guo H (2008) Displacement, stress and seismicity in roadway roofs during mining-induced failure. Int J Rock Mech Min Sci 45:672–688CrossRefGoogle Scholar
  18. Tan YL, Yu FH, Chen L (2013) A new approach for predicting bedding separation of roof strata in underground coalmine. Int J Rock Mech Min Sci 61:183–188Google Scholar
  19. Wang M, Bai JB, Wang XY, Yu Y, Guo YH, Cao JL (2012a) The surrounding rock deformation rule and control technique of the roadway driven along goaf and heading for adjacent advancing coal face. J Min Saf Eng 29(2):194–202 (in Chinese) Google Scholar
  20. Wang C, Du ZS, Qian D, Zhang N (2012b) Research on coal pillar width and its reinforcement technology of gob-side entry driving at insular face. J Henan Polytechnic Uni (Nat Sci) 31(6):655–659 (in Chinese) Google Scholar
  21. Wang WJ, Hou CJ, Bai JB et al (2001) Mechanical deformation analysis of the roof coal of road driving along next goaf in sublevel caving face. China J Geotech Eng 23(2):209–211 (in Chinese) Google Scholar
  22. Wang C, Zhang N, Li GC, Zhang NC (2011) De-stressed mining of multi-seams: surrounding rock control for mining influenced roadway in the overlying protected seam. Min Sci Tech (China) 21:159–164CrossRefGoogle Scholar
  23. Xie XZ, Fan ZZ, Huang ZZ, Xu G (2011) Research on unsymmetrical loading effect induced by the secondary mining in the coal pillar. Procedia Eng 26:725–730CrossRefGoogle Scholar
  24. Yang TH, Xu T, Liu HY, Tang CA, Shi BM, Yu QX (2011a) Stress-damage-flow coupling model and its application to pressure relief coal bed methane in deep coal seam. Int J Coal Geol 86:357–366CrossRefGoogle Scholar
  25. Yang W, Lin BQ, Qu YA, Li ZW, Zhai C, Jia LL, Zhao WQ (2011b) Stress evolution with time and space during mining of a coal seam. Int J Rock Mech Min Sci 48:1145–1152CrossRefGoogle Scholar
  26. Yuan L (2007) Study on critical modern technology for mining in gassy deep mines. J China Uni Min Tech 17(2):226–231 (in Chinese) CrossRefGoogle Scholar
  27. Yuan L (2009) Technique of coal mining and gas extraction without coal pillar in multi-seam with low permeability. J Coal Sci Eng 15(2):120–128CrossRefGoogle Scholar
  28. Yang JP, Cao SG, Li XH (2013) Failure laws of narrow pillar and asymmetric control technique of gob-side entry driving in island coal face. Int J Min Sci Tech 23:267–272CrossRefGoogle Scholar
  29. Zhang N, Li XH, Gao MS (2004) Pretensioned support of roadway driven along next gob and heading adjacent advancing coal face and its application. Chin J Rock Mech Eng 23(12):2100–2105 (in Chinese) Google Scholar
  30. Zhang N, Wang C, Zhao YM (2009) Rapid development of coalmine bolting in China. Procedia Earth Planet Sci 1(1):41–46CrossRefGoogle Scholar
  31. Zheng XG, Yao ZG, Zhang N (2012) Stress distribution of coal pillar with gob-side entry driving in the process of excavation & mining. J Min Saf Eng 29(4):459–465 (in Chinese) Google Scholar
  32. Zhang Y, Wan ZJ, Li FC, Zhou CB, Zhang B, Guo F, Zhu CT (2013) Stability of coal pillar in gob-side entry driving under unstable overlying strata and its coupling support control technique. Int J Min Sci Tech 23:193–199CrossRefGoogle Scholar

Copyright information

© Saudi Society for Geosciences 2015

Authors and Affiliations

  1. 1.Department of Earth Resources Engineering, Faculty of EngineeringKyushu UniversityFukuokaJapan
  2. 2.School of MinesChina University of Mining and TechnologyXuzhouChina
  3. 3.School of Energy Science and EngineeringHenan Polytechnic UniversityJiaozuoChina
  4. 4.School of Earth SciencesUniversity of QueenslandSt LuciaAustralia

Personalised recommendations