Advertisement

Design of rhombus coal pillars and support for Roadway Stability and mechanizing loading of face coal using SDLs in a steeply inclined thin coal seam—a technical feasibility study

  • Mohammad Jawed
  • Rabindra Kumar Sinha
Original Paper
  • 83 Downloads

Abstract

Coal seams that dip more than 15° are classified as steeply inclined in Indian mining context. Mining of steeply inclined seams poses variety of problems starting from strata control to problems related to efficient mechanisation. Sawang-C seam of Govindpur Underground Project of Central Coalfields Limited is one such seam. Presently, the seam is being developed on bord and pillar method of mining, and the blasted coal is loaded manually into tubs using hand shovel and basket. In order to mechanise the loading operation, technical feasibility of formation of rhombus pillars and deployment of side discharge loader (SDL) are investigated along with design of supports from the point of view of roadway stability. This paper thus seeks to address the technical feasibility of deployment of Side Discharge Loader in a 1.7–2.2-m thin seam inclined at 16° if developed with rhombus pillars and to suggest suitable and adequate support system for such workings.

Keywords

Bord and pillar mining Steeply inclined seams Rhombus pillars Thin seams Numerical modelling 

Notes

Acknowledgements

The authors are thankful to the participants of the Consultancy Project (CONS/3116/2015-16) titled ‘Design of rhombus coal pillars and support with roadway stability of Sawang-C seam of Govindpur underground project sponsored by Central Coalfields Limited, a Subsidiary of Coal India Limited. The views expressed in this paper are those of the authors, and not necessarily of the institute which they belong to. The authors also acknowledge the contributions of Mr. Aditya Mishra and Mr. Vijay Shekar, Scientist, NIRM, Bengaluru, India for some of the numerical modelling analysis.

References

  1. Agapito JFT, Hardy MP (1982) Induced horizontal stress method of pillar design in oil shale. In: proc. 15th oil shale symposium. Colorado School of Mines, Golden, pp 191–197Google Scholar
  2. Balmer G (1952) A general analytical solution for Mohr’s envelope. American Society for Testing Materials 52:1260–1271Google Scholar
  3. Bieniawski ZT (1968) The effect of specimen size on compressive strength of coal. Int J Rock Mech Min Sci Geomech Abstr 5:325–335.  https://doi.org/10.1016/0148-9062(68)90004-1 CrossRefGoogle Scholar
  4. Bieniawski ZT, Van Heerden WL (1975) The significance of in situ tests on large rock specimens. Int J Rock Mech Min Sci Geomech Abstr 12:101–113.  https://doi.org/10.1016/0148-9062(75)90004-2 CrossRefGoogle Scholar
  5. Bunting D (1911) Chamber pillars in deep anthracite mines. Trans AIME 42:236–245Google Scholar
  6. Cook NGW, Hodgson K, Hojem JPM (1971) A 100-MN jacking system for testing coal pillars underground. J South Afr Inst Min Metall:215–224Google Scholar
  7. De Qi J, Chai J, Zhang JZ (2014) Numerical Design of Pillar Width in the inclined coal seam. Adv Mater Res 977:361–364.  https://doi.org/10.4028/www.scientific.net/AMR.977.361 CrossRefGoogle Scholar
  8. Gaddy FL (1956) A study of the ultimate strength of coal as related to the absolute size of the cubical specimens tested. Bull Virginia Polytech Inst 112:1–27Google Scholar
  9. Gale WJ (1999) Experience of field measurement and computer simulation methods of pillar design. In: Mark C, Heasley KA, Iannacchione AT, Tuchman RJ (eds) Proceedings of the second international workshop on coal pillar mechanics and design, National Institute for Occupational Safety and Health, IC. Vol. 9448. pp 49–61Google Scholar
  10. Galvin JM (1999) University of New South Wales coal pillar strength determinations for Australian and South African mining conditions. In: Second International Workshop Coal Pillar Mech. and Design. NIOSH Inf Circ. 9448. pp 63–71Google Scholar
  11. Greenwald HP, Howarth HC, Hartmann I (1939) Experiments on strength of small pillars of coal in the Pittsburgh bed. U.S. bur. Mines, no. BM-TP-605, R.I. 3575Google Scholar
  12. Hoek E, Brown ET (1980) Underground excavations in rock. Institution of Mining and Metallurgy, LondonGoogle Scholar
  13. Holland CT, Gaddy FL (1957) Some aspects of permanent support of overburden on coal beds. Proc West Virginia Coal Min Inst 43–65Google Scholar
  14. Hustrulid WA (1976) A review of coal pillar strength formulas. Rock Mech 8:115–145.  https://doi.org/10.1007/BF01239762 CrossRefGoogle Scholar
  15. IS 14480 (2006) Indian Standard, Side -discharge loaders for underground coal mines - safety requirements, operation and maintenance - code of practiceGoogle Scholar
  16. Jawed M, Sinha RK, Sengupta S (2013) Chronological development in coal pillar design for bord and pillar workings: a critical appraisal. J Geol Min Res 5:1–11.  https://doi.org/10.5897/JGMR12.010 CrossRefGoogle Scholar
  17. Kushwaha A, Banerjee G (2005) Exploitation of developed coal mine pillars by shortwall mining - a case example. Int J Rock Mech Min Sci 42:127–136.  https://doi.org/10.1016/j.ijrmms.2004.08.004 CrossRefGoogle Scholar
  18. Kushwaha A, Singh SK, Tewari S, Sinha A (2010) Empirical approach for designing of support system in mechanized coal pillar mining. Int J Rock Mech Min Sci 47:1063–1078.  https://doi.org/10.1016/j.ijrmms.2010.06.001 CrossRefGoogle Scholar
  19. Lianjin T (2000) Roof behavior analysis of inclined coal seam. In: ISRM international symposium. November, Melbourne, pp 19–24Google Scholar
  20. Logie CV, Matheson GM (1982) A critical review of the current state-of-the-art design of mine pillars. In: Brawner CO (ed) Proceedings of the first international conference of stability of underground mining. pp 359–382Google Scholar
  21. Loui JP, Jhanwar JC, Sheorey PR (2007) Assessment of roadway support adequacy in some Indian manganese mines using theoretical in situ stress estimates. Int J Rock Mech Min Sci 44:148–155.  https://doi.org/10.1016/j.ijrmms.2006.04.009 CrossRefGoogle Scholar
  22. Madden BJ (1991) A re-assessment of coal pillar design. J South Afr Inst Min Metall 91:27–37Google Scholar
  23. Maleki H (1992) In situ pillar strength and failure mechanisms for US coal seams. In: Proceedings of the workshop on coal pillar mechanics and design. Pittsburgh: US Department of the Interior, Bureau of Mines, pp 73–77Google Scholar
  24. Mark C, Barton TM (1997) Pillar design and coal strength. Proceedings-new Technol gr control retreat mining Pittsburgh, PA US dep heal hum Serv public heal Serv centers dis control Prev Natl Inst Occup Saf heal DHHS (NI 49–59Google Scholar
  25. Mark C, Chase FE (1997) Analysis of retreat mining pillar stability (ARMPS). In: Proceedings-new Technology for Ground Control in retreat mining. Pittsburgh, PA: US Department of Health and Human Services, public health service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NI. pp 17–34Google Scholar
  26. Mathur SP (2012) Underground mining. In: Mathur SP, Singh NK (eds) Coal mining and management - Vol. II, 1st edn. Khanna publishers, Bilaspur, p II-2-1 to 116Google Scholar
  27. Mitri HS, Edrissi R, & Henning JG (1995) Finite-element modeling of cable-bolted stopes in hard-rock underground mines. Trans Min Metall Explor Inc 1897–1902Google Scholar
  28. Murali Mohan G, Sheorey PR, Kushwaha A (2001) Numerical estimation of pillar strength in coal mines. Int J Rock Mech Min Sci 38:1185–1192.  https://doi.org/10.1016/S1365-1609(01)00071-5 CrossRefGoogle Scholar
  29. Obert L, Duvall W (1967) Rock mechanics and the Design of Structures in rock. John Wiley & Sons Inc., HobokenGoogle Scholar
  30. Paul SK, Ghose AK, Raju NM, et al (1990) Report of the expert group on guidelines for drawing up support plans in Bord and pillar workings in coal mines, directorate general of mines safety, Dhanbad, IndiaGoogle Scholar
  31. Poulsen BA (2010) Coal pillar load calculation by pressure arch theory and near field extraction ratio. Int J Rock Mech Min Sci 47:1158–1165.  https://doi.org/10.1016/j.ijrmms.2010.06.011 CrossRefGoogle Scholar
  32. Raju NM, Sinha A, Venkateswarlu V, Ram SN (1987) CMRS Report on Geomechanical Classification of Coal Measure Roof Rocks vis-a-vis Roof SupportsGoogle Scholar
  33. Salamon MDG, Munro AH (1967) A study of the strength of coal pillars. J South Afr Inst Min Metall 68:55–67Google Scholar
  34. Sheorey PR (1992) Pillar strength considering in situ stresses. In: Iannacchione AT (ed) Proceedings of the workshop on coal pillar mechanics and design, U.S. Department of Interior, Bureau of Mines, IC 9315. pp 122–127Google Scholar
  35. Sheorey PR (1994) A theory for in situ stresses in isotropic and transverseley isotropic rock. Int J Rock Mech Min Sci 31:23–34.  https://doi.org/10.1016/0148-9062(94)92312-4 CrossRefGoogle Scholar
  36. Sheorey PR (1997) Empirical Rock Failure Criteria, First Edit. Oxford & IBH Publishing Co. Pvt. Ltd., New DelhiGoogle Scholar
  37. Sheorey PR, Bandopadhyay C, Das MN, Singh TN, Biswas AK, Prasad RK, Barat D, Rao R (1987a) Optimisation of design of mine pillar parameters andfeasibility of extraction of locked-up coal below built-up structures, water-logged areas and hard covers. Report of grant in aid project. Central Mining Research Station, DhanbadGoogle Scholar
  38. Sheorey PR, Das MN, Barat D, Prasad RK, Singh B (1987b) Coal pillar strength estimation from failed and stable cases. Int J Rock Mech Min Sci 24:347–355.  https://doi.org/10.1016/0148-9062(87)92256-X CrossRefGoogle Scholar
  39. Singh RD (2007) Principles and practices of modern coal mining. New Age International (P) Ltd., New DelhiGoogle Scholar
  40. Singh R, Kumar A, Singh AK, Coggan J, Ram S (2016) Rib/Snook design in mechanised depillaring of rectangular/square pillars. Int J Rock Mech Min Sci 84:119–129.  https://doi.org/10.1016/j.ijrmms.2016.02.008 CrossRefGoogle Scholar
  41. Sinha A, Ghosh AK, Rao DG, Singh AK, Singh SK, Murali MG, Kumar N (2002) In situ stress measurement in underground coal mines and its application to stability analysis. S&T Report, Funded from Coal S&T Grant of Ministry of Coal, Government of India, Central Mining Research Institute, DhanbadGoogle Scholar
  42. Sinha RK, Sengupta S, Gupta RN (2004) Implementing Total Productive Maintenance (TPM) in Mineral Industry. In: ENTMS 2004- Geominetech Symposium 11–12 May. pp 149–153Google Scholar
  43. Sinha RK, Jawed M, Sengupta S (2013) Influence of anisotropic stress conditions on Design of Development Workings in Bord and pillar mining. ISRM(India) J 2:16–24Google Scholar
  44. Sinha RK, Jawed M, Sengupta S (2015a) Influence of rock mass rating and in situ stress on stability of roof rock in bord and pillar development panels. Int J Min Miner Process Eng 6:258–275.  https://doi.org/10.1504/IJMME.2015.071175 CrossRefGoogle Scholar
  45. Sinha RK, Jawed M, Sengupta S (2015b) Design of support system in depillaring panel using numerical modelling– a case study. Int J Earth Sci Eng 8(6):2678–2686Google Scholar
  46. Trumbachev VF, Melnikov EA (1964) Distribution of stresses in the intervening pillars at medium and steep dips. In: 4th Conference on Strata Control and Rock Mechanics, New York, pp 316–322Google Scholar
  47. Venkateswarlu V, Sripad N, Gandhe A, Benady S (2007) Optimisation of pillar parameters for development and final extraction of highly inclined seams of SCCL mines. NIRM, Coal S&T Project no. MT-115/GC 99-07-R, funded by Ministry of Coal, Govt. of IndiaGoogle Scholar
  48. Wagner H (1974) Determination of the complete load-deformation characteristics of coal pillars. In: proceedings of the third international congress on rock mechanics. National Academy of Sciences. Vol. 2. New York, pp 1076–1081Google Scholar
  49. Wagner H, Madden BJ (1984)Fifteen years’ experience with the design of coal pillars in shallow South African collieries. In: Design and performance of underground excavations. International Society for Rock Mechanics, Cambridge, pp 391–399Google Scholar
  50. Wei G (2014) Study on the width of the non-elastic zone in inclined coal pillar for strip mining. Int J Rock Mech Min Sci 72:304–310.  https://doi.org/10.1016/j.ijrmms.2014.09.013 CrossRefGoogle Scholar
  51. Wen M (2013) Numerical simulation of underground pressure in mining high-inclined coal-seam with analysis of material properties in mine Dongbaowei. Adv Mater Res 644:382–386.  https://doi.org/10.4028/www.scientific.net/AMR.644.382 CrossRefGoogle Scholar
  52. Wilson AH (1972) An hypothesis concerning pillar stability. Min Eng 131:409–417Google Scholar
  53. Wilson AH (1982) Pillar stability in longwall mining. In: Chugh YP, Karmis M (eds) Proceedings: state-of-the-art of ground control in longwall mining and mining subsidence. pp 85–95Google Scholar
  54. Yajun X, Panfeng G, Fudong G (2014) International journal of mining science and technology analysis of stability of support and surrounding rock in mining top coal of inclined coal seam. Int J Min Sci Technol 24:63–68.  https://doi.org/10.1016/j.ijmst.2013.12.011 CrossRefGoogle Scholar

Copyright information

© Saudi Society for Geosciences 2018

Authors and Affiliations

  1. 1.Indian Institute of Technology (Indian School of Mines)DhanbadIndia

Personalised recommendations