Journal of Korean Tunnelling and Underground Space Association (한국터널지하공간학회 논문집)

Korean Tunnelling and Underground Space Association (한국터널지하공간학회)
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A numerical study on evaluation of unsupported pillar strength in the room and pillar method

주방식 공법에서 무지보 암주의 강도 산정에 관한 수치해석적 연구

  • Lee, Chulho (Geotechnical Engineering Research Division, Korea Institute of Construction Technology) ;
  • Chang, Soo-Ho (Geotechnical Engineering Research Division, Korea Institute of Construction Technology) ;
  • Shin, Hyu-Soung (Geotechnical Engineering Research Division, Korea Institute of Construction Technology)
  • 이철호 (한국건설기술연구원 SOC성능연구소 Geo-인프라연구실) ;
  • 장수호 (한국건설기술연구원 SOC성능연구소 Geo-인프라연구실) ;
  • 신휴성 (한국건설기술연구원 SOC성능연구소 Geo-인프라연구실)
  • Received : 2013.07.15
  • Accepted : 2013.07.28
  • Published : 2013.07.31
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Abstract

This study aims to evaluate the mechanical behaviors of unsupported rock pillars in a room-and-pillar underground structure by a series of numerical analyses. In addition, rock pillar strengths estimated by a few empirical equations proposed for underground mines are compared with those from numerical analyses. Based on the results from the numerical analysis, the ratio of pillar strength to rock mass strength increases as the ratio of the width of a pillar to its height becomes bigger. It means that higher ratio of pillar width to its height is much more favorable for stabilizing a room-and-pillar underground structure. Especially, unsupported pillar strengths estimated from numerical analyses are higher than rock mass strength when the ratio of pillar width to height is approximately over 1.5. It is also found that the choice of an empirical equation appropriate for a given geometric condition of a pillar is important for its feasible application to the stability analysis of a pillar in the room-and-pillar method.

본 연구에서는 주방식 지하구조물의 안정성을 좌우하는 무지보 암주의 거동을 수치해석에 의해 검토하였다. 암주의 강도를 추정하기 위해 기존 연구들에서 제시된 경험식들을 수치해석 결과와 비교 분석하였다. 분석 결과, 암주의 폭이 높이보다 커질수록 암주 강도와 암반 강도의 비율이 증가하여 안정성 확보에 유리한 것으로 나타났다. 특히, 본 연구의 해석조건에서는 암주의 폭과 높이의 비율이 약 1.5 이상이면 무지보 암주의 강도가 암반의 압축강도보다 크게 얻어졌다. 또한 암주의 형상 조건에 따라 수치해석 결과와 유사한 결과를 산출하는 경험식이 다소 상이하여, 현장자료 기반의 경험식을 활용하기 위해서는 암주의 형상 조건에 따라 적합한 경험식을 적용하는 것이 필요하다.

Keywords

References

  1. Aydan, O., Dalgic, S. (1998), "Prediction of deformation behaviour of 3 lanes Bolu tunnels through squeezing rocks of North Anotolian Fault Zone (NAFZ)", In: Proceedings of the regional symposium on sedimentary rock engineering, Taipei, pp. 228-233.
  2. Bieniawski, Z.T. (1973), "Engineering classification of jointed rock masses", Trans S Afr Inst Civ Eng, Vol. 15, No. 12, pp. 335-344.
  3. Bieniawski, Z.T. (1988), "Rock mass rating systems in engineering practice". Symposium on Rock Classification Systems for Engineering Purposes, ASTM, STP 984, pp. 17-34.
  4. Bieniawski, Z.T. (1989), Engineering rock mass classification, Wiley, New York.
  5. Bieniawski, Z.T. (1993), "Classification of rock masses for engineeringthe RMR system and future trends", J.A. Hudson (Ed.), Comprehensive rock engineering, Vol. 3, Pergamon Press, UK, pp. 553-573.
  6. Carmody, J., Sterling, R. (1993), Underground Space Design - A guide to Subsurface Utilization and Design for People in Underground Spaces, International Thomson Publishing company, p. 110.
  7. Carter, B.J., Duncan, E., Scott, J., Lajtai, E.Z. (1991), "Fitting strength criteria to intact rock", Int. J. Geotechnol. Geol. Eng., Vol. 9, pp. 73-81. https://doi.org/10.1007/BF00880985
  8. Dinc, O.S., Sonmez, H., Tunusluoglu, C., Kasapoglu, K.E. (2011), "A new general empirical approach for the prediction of rock mass strengths of soft to hard rock masses", International Journal of Rock Mechanics and Mining Sciences, Vol. 48, Issue 4, pp. 650-665. https://doi.org/10.1016/j.ijrmms.2011.03.001
  9. Esterhuizen, G.S., Dolinar, D.R., Ellenberger, J.L, Prosser, LJ. (2011), Pillar and roof span design guidelines for underground stone mines, Department Of Health And Human Services, NIOSH, IC 9526.
  10. Esterhuizen, G.S., Dolinar, D.R., Ellenberger, J.L. (2008), "Pillar strength and design methodology for stone mines", In: Proceedings of the 27th international conference on ground control in mining. Morgantown WV: West Virginia University, pp. 241-253.
  11. Esterhuizen, G.S. (2006), "An evaluation of the strength of slender pillars". SME annual meeting and exhibit, March 27-29, St. Louis, Missouri, preprint 06-003. Society for Mining, Metallurgy, and Exploration, Inc., Littleton.
  12. Gonzalez-Nicieza, C., Alvarez-Fernadez, M.I., Menendez-Diaz, A., Alvarez-Vigil, A.E. (2006), "A comparative analysis of pillar design methods and its application to marble mines", Rock Mech. Rock Engng., Vol. 39, No. 5, pp 421-444. https://doi.org/10.1007/s00603-005-0078-z
  13. Dinc, O.S., Sonmez, H., Tunusluoglu, C., Kasapoglu, K.E. (2011), "A new general empirical approach for the prediction of rock mass strengths of soft to hard rock masses", International Journal of Rock Mechanics and Mining Sciences, Vol. 48, Issue 4, pp. 650-665. https://doi.org/10.1016/j.ijrmms.2011.03.001
  14. Hardy, P., Agapito, J.F.T. (1982), "Induced horizontal stress method of pillar design in oil shale", XV Oil Shale Symp. Colorado School of Mines, Golden, Colorado.
  15. Hartman, H.L., Mutmansky, J.M. (2002), Introductory Mining Engineering, 2nd edtion, Wiley, New Jersey.
  16. Hedley, D.G.F., Grant, F. (1972), "Stope-andpillar design for the elliot lake uranium mines", Bull. Can. Inst. Min. Metallurg. Vol. 63, pp. 37-44.
  17. Hoek, E., Brown, E.T. (1980), Underground excavation in rock, Institution of Mining and Metallurgy.
  18. Hoek, E., Carranza-Torres, C.T., Corkum, B. (2002), "Hoek-Brown failure criterion-2002 edition", In: Proceedings of the fifth north american rock mechanics symposium, Toronto, pp. 267-273.
  19. Kalamaras, G.S., Bieniawski, Z.T. (1995), "A rock strength concept for coal seams incorporating the effect of time", Proceedings of the Eighth International Congress on Rock Mechanics, Vol. 1, pp. 295-302.
  20. Kim, W.-B., Yang, H.-S., Ha, T.-W. (2012) "An assessment of rock pillar behavior in very near parallel tunnel", Journal of Korean Society for Rock Mechanics, Vol. 22, No. 1, pp. 60-68 (in Korean) https://doi.org/10.7474/TUS.2012.22.1.060
  21. Kimmelmann, M.R., Hyde, B., Madgwick, R.J. (1984), "The use of computer applications at BCL limited in planning pillar extraction and design of mining layouts", In: Proc., ISMR Symp. Design and Performance of Underground Excavations. Brit. Geotech. Soc., London, pp. 53-63.
  22. Krauland, N., Soder, P.E. (1987), "Determinating pillar strength from pillar failure observations", Eng. Min. J. Vol. 8, pp. 34-40.
  23. Lunder, P.J., Pakalnis, R. (1997), "Determination of the strength of hard-rock mine pillars", Bull. Can. Inst. Min. Metall. Vol. 90, pp. 51-59.
  24. Palmström, A. (1995), RMi-a rock mass characterization system for rock engineering purposes. Ph.D. thesis, University of Oslo, Norway.
  25. Potvin, Y., Hudyma, M.R., Miller, H.D.S. (1989), "Design guidelines for open stope support", Bull. Can. Min. Metall. Vol. 82, pp. 53-62.
  26. Ramamurthy, T. (2004), "A geo-engineering classification for rocks and rock masses", International Journal of Rock Mechanics and Mining Sciences, Vol. 41, Issue 1, pp. 89-101. https://doi.org/10.1016/S1365-1609(03)00078-9
  27. Ramamurthy, T. (1986), "Stability of rock mass", Indian Geotech J, pp. 1-74.
  28. Sheorey, P.R. (1997), Empirical rock failure criteria, Balkema, Rotterdam.
  29. Sheorey, P.R., Loui, J.P., Singh, K.B., Singh, S.K. (2000), "Ground subsidence observations and a modified influence function method for complete subsidence prediction", Int. J. Rock Mech. Min. Sci. Vol. 37, pp. 801-818. https://doi.org/10.1016/S1365-1609(00)00023-X
  30. Shin, Y.-W., Kim, Y.-G. (2010) "Review of mechanical behaviors of pillar in large parallel tunnel", Journal of Korean Society for Rock Mechanics, Vol. 20, No. 3, pp. 131-144 (in Korean).
  31. Yudhbir, Y., Lemanza, W., Prinzl, F. (1983), "An empirical failure criterion for rock masses", In: Proceedings of the fifth international congress society of rock mechanics, Melbourne, Vol. 1, pp. B1-8.

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