한국지반공학회논문집 (Journal of the Korean Geotechnical Society)

  • 제25권8호
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  • Pages.77-93
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  • 2009
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  • 1229-2427(pISSN)
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  • 2288-646X(eISSN)
한국지반공학회 (Korean Geotechnical Society)
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암반에 근입된 현장타설말뚝의 선단하중전이거동 분석

End Bearing Load Transfer Behavior of Rock Socketed Drilled Shafts

  • 발행 : 2009.08.31
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초록

본 연구에서는 3차원 유한차분해석을 통하여 말뚝직경, 암반물성, 불연속면의 간격 및 방향 등 주요 인자가 암반근입 현장타설말뚝의 선단거동에 미치는 영향에 대한 분석을 수행하였으며, 이를 토대로 초기기울기 및 극한 단위선단지지력을 변수로 하는 쌍곡선형태의 선단하중전이(q-w)함수를 제안하였다. 제안식의 국내 암반지반에의 적용을 위하여 국내에서 수행된 14개 현장 23본의 시험말뚝의 재하시험자료를 토대로 제안식의 경험계수를 산정하였으며, 더불어 기존 초기기울기 및 극한단위선단지지력 산정식의 타당성 검토도 수행하였다. 현장재하시험 사례와의 비교분석 결과, 본 연구에서 제안된 산정식은 국내 암반지반에 근임된 현장타설말뚝의 선단거동을 비교적 잘 예측 가능하고, 말뚝지지력 및 침하량 예측값이 실측값에 가까움을 알 수 있었다.

The load distribution and deformation of rock socketed drilled shafts subjected to axial loads were evaluated by a load transfer approach. The emphasis was laid on quantifying the end bearing load transfer characteristics of rock socketed drilled shafts based on 3D Finite Difference (FD) analysis performed under varying rock strength and rock mass conditions. From the results of FD analysis, it was found that the ultimate unit toe resistance ($q_{max}$) was influenced by both rock strength and rock mass conditions, while the initial tangent of end bearing load transfer curve ($G_{ini}$) was only dependent on rock strength. End bearing load transfer function of drilled shafts socketed in rock was proposed based on the FD analysis and the field loading tests which were performed on weathered rock in South Korea. Through the comparison with the results of the field loading tests, it is found that the load transfer curve by the present study is in good agreement with the general trend observed by field loading tests, and thus represents a significant improvement in the prediction of load transfer behavior of drilled shaft.

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참고문헌

  1. 권오성 (2004), 암반의 풍화도가 암반근입말뚝의 지지거동에 미치는 영향, 박사학위논문, 서울대학교
  2. 김태형 (2008), Hoek-cell 압축시험을 통한 암반에 근입된 현장타설말뚝의 선단 하중전이함수 제안, 석사학위논문, 연세대학교
  3. 전경수 (2000), 풍화암에 근입된 현장타설말뚝의 연직 및 횡방향 지지거동 분석, 박사학위논문, 서울대학교
  4. 조천환, 이명환, 김성회 (2003), "국내 현장타설말뚝의 주면 접촉부에 대한 일정강성도 전단시험" 한국지반공학회 정기학술대회, pp.147-152
  5. AASHTO (1996), Standard Specifications for Highway Bridges, 16th Ed., American Association of State Highway and Transportation Officials, Washington, D.C
  6. Alehossein, H., Carter, J. P., and Booker, J. R. (1992), "Finite element analysis of rigid footings on jointed rock", Proc., 3rd Int. Conf. on Comp. Plasticity, Vol.1, pp.935-945
  7. ARGEMA (1992), Design guides for offshore structures : Offshore pile design, ED: P. L. Tirant, Editions Technip, Paris, France
  8. Armalesh, S. and Desai, C. S. (1987), "Load-Deformation Response of Axially Loaded Piles", Journal of Geotechnical Engineering Division, ASCE, Vol.113, No.GT12, pp.1483-1500 https://doi.org/10.1061/(ASCE)0733-9410(1987)113:12(1483)
  9. Baquelin, F. (1982), "Rules for the structural design of foundations based on the selfboring pressuremeter test", Symp. on the Pressuremeter and Its Marine Application, IFP, Paris, pp.347-362
  10. Baquelin, F., Frand, R., and Jezequel, J. F. (1982), "Parameters for friction piles in marine soils", 2nd International Conference in Numerical Methods for Offshore Piling, Austin, April
  11. Booker, J. R. (1991), "Analytical methods in geomechanics", Proc., 7th Int. Conf. on Comp. Methods and Advances in Geomech., Balkema, Rotterdam, The Netherlands, Vol.1, pp.3-14
  12. Canadian Geotechnical Society (1985), Foundation Engineering Manual, Part 2(2nd ed), Canadian Geotechnical Society, Vancouver, Canada
  13. Carter, J.P. and Kulhawy, F.H. (1988), Analysis and design of drilled shaft foundations socketed into rock, Final report, EL 5918/ Project 1493-4 / Electric Power Research Institute, Conell Univ., Ithaca, NY
  14. Castelli, F., Maugeri, M., and Motta, E. (1992), "Analisi non lineare del cedimento di un Palo Singolo", Rivista Italiana di Geotechnica, Vol.26(2), pp.115-135
  15. Coates, D. F. (1967), Rock mechanics principles, Energy, Mines and Resources, Ottawa, Canada, Monograph 874
  16. De Beer, E. (1986), "Different behavior of bored and driven piles", Proc. of 6th Danubian Conf. on Soil Mech. and Found. Eng., pp.307-318
  17. FHWA (1999), Drilled Shafts: Construction Procedures and Design Methods, FHWA Publication No. FHWA-IF-99-025, Department of Transportation, Federal Highway Administration, Office of Implementation, McLean, VA
  18. Fioravante, V., Jamiolkowski, M. and Pedroni, S. (1994), "Modelling the behaviour of Piles in sand subjected to axial load", Int. Conf. Centrifuge, pp.455-460, Balkema, Rotterdam
  19. Geotechnical Engineering Office (1996), Pile design and construction (GEO Publication No. 1/96), Geotechnical Engineering Office, Hong Kong, 348p
  20. Ghionna, V. N., Jamiolkowski, M., Lancellotta, R., and Pedroni, S. (1993), "Base capacity of bored piles in sands from in situ tests",Proc., 2nd Int. Geotech. Seminar on Deep Found. on Bored and Augered Piles, Balkema, Rotterdam, Brookfield, pp.67-75
  21. Gwizdala, K. (1984), Determination of the Bearing Capacity and Settlement from the Results of Static Penetration Tests CPT and Standard Penetration Tests SPT, Report No. 26, Swedish Geotechnical Institute, Linkoping, pp.1-129
  22. Itasca Consulting Group, Inc. (1997), FLAC, Fast Lagrangian Analysis of Continua, Ver. 3.3, Vol. I : User's Manual. Itasca Consulting Group, INC
  23. Kerisel, J. (1958), "La mecanique des sols: recherches et investigation recentes", Rev. Trav., Paries, pp.874-878
  24. Kim, S. I., Jeong, S. S., Cho, S. H., and Park, I. J. (1999), "Shear Load Transter Characteristics of Drilled Shafts in Weathered Rocks", Journal of Geotechnical and Geoenvironmental Engineering, ASCE, Vol.125(11), pp.999-1010 https://doi.org/10.1061/(ASCE)1090-0241(1999)125:11(999)
  25. O'Neill, M. W., and Hassan, K. M. (1994), "Drilled shaft : effects of construction on performance and design criteria", Proceedings of the International Conference on Design and Construction of Deep Foundations, Federal Highways Administration, Washington D.C., Vol.1, pp.137-187
  26. Priest, S. D., and Hudson, J. A. (1976), "Discontinuity spacings in rock", International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts, Vol.13, pp.135-148
  27. Randolph, M.F., and Wroth, C. P. (1978), "Analysis of Deformation of Vertically Loaded Piles", Journal of the Geotechnical Engineering Division, ASCE, Vol.104, No.GT12, pp.1465-1488
  28. Reese, L. C., and O'Neill, M. W. (1988), Drilled shafts : Construction procedures and design methods, Publ. No. FHWA-HI- 88-042, Federal Highway Administration, Washington, D. C
  29. Rowe, P. K., and Armitage, H. H. (1987), "Theoretical Solutions for Axial Deformation of Drilled Shafts in Rock", Canadian Geotechnical Journal, Vol.24, pp.114-125 https://doi.org/10.1139/t87-010
  30. Seol, H. I, Jeong, S. S., Cho, C. H., and You, K. H. (2008). "Shear Load Transfer for Rock-Socketed Drilled Shafts based on Borehole Roughness and Geological Strength Index (GSI)", International Journal of Rock Mechanics and Mining Sciences. Vol.45, pp.848-861 https://doi.org/10.1016/j.ijrmms.2007.09.008
  31. Teng, W. C. (1962), Foundation Design, Prentice-Hall Inc., Englewood Cliffs, N. J
  32. Timoshenko, S. P., and Goodier, J. N. (1970), Theory of Elasticity, 3ed Ed., McGraw-Hill Book Co., pp.403-409
  33. Williams, A.F., Johnston, I. W., and Donald, I. B. (1980), "The design of socketed piles in weak rock", Proceedings of international conference on structural foundations on rock, Balkema, Sydney, pp.327-347
  34. Yu, H. S., and Sloan, S. W. (1994), "Bearing capacity of jointed rock", Proc., 8th Int. Conf. on Comp. Methods and Advances in Geomech., Balkema, Rotterdam, The Netherlands, Vol.3, pp.2403-2408
  35. Zhang, L, and Einstein, H. H. (1998), "End bearing capacity of drilled shafts in rock", Journal of Geotechnical and Geoenvironmental Engineering, Vol.124, No.7, pp.574-584 https://doi.org/10.1061/(ASCE)1090-0241(1998)124:7(574)