한국지반공학회논문집 (Journal of the Korean Geotechnical Society)

  • 제31권8호
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  • Pages.39-49
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  • 2015
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  • 1229-2427(pISSN)
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  • 2288-646X(eISSN)
한국지반공학회 (Korean Geotechnical Society)
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원심모형실험을 통한 파형 마이크로파일의 연직 지지력 평가

Evaluation of Axial Bearing Capacity of Waveform Micropile by Centrifuge Test

  • 장영은 (과학기술연합대학원대학교 지반신공간공학과) ;
  • 한진태 (한국건설기술연구원 지반연구소) ;
  • 김재현 (KAIST, 건설및환경공학과) ;
  • 박헌준 (KAIST, 건설및환경공학과) ;
  • 김상환 (호서대학교 토목공학과)
  • Jang, Young-Eun (Dept. of Geospace Engrg., Univ. of Science & Technology) ;
  • Han, Jin-Tae (Dept. of Geotechnical Engrg., Korea Institute of Civil Engrg. and Building Technology, UST) ;
  • Kim, Jae-Hyun (Dept. of Civil and Environmental Engrg., KAIST) ;
  • Park, Heon-Joon (Dept. of Civil and Environmental Engrg., KAIST) ;
  • Kim, Sang-Hwan (Dept. of Civil Engrg., Hoseo Univ.)
  • 투고 : 2015.05.20
  • 심사 : 2015.08.03
  • 발행 : 2015.08.31
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초록

본 논문에서는 jet grouting 공법을 적용한 파형 마이크로파일의 지지력 향상 효과 및 거동 특성을 분석하기 위한 연구를 수행하였다. 각 말뚝의 형상에 따른 거동을 비교하기 위해 일반 마이크로파일, 파형이 없는 jet grouted 말뚝 및 네 종류의 파형 마이크로파일의 모델을 제작하여 원심모형실험을 수행하였다. 실험 결과 일반 마이크로파일 대비 파형 마이크로파일의 지지력 향상 효과를 확인 할 수 있었으며, 특히 파형의 간격이 상대적으로 좁은 말뚝의 지지력 개선 효과가 큰 것으로 분석되었다. 또한 기존의 재하시험에 의한 지지력 예측 및 평가 방법을 토대로 파형 마이크로 파일의 지지력 산정 방안을 검토한 결과 P-S 곡선법과 25.4mm 전침하량기준이 파형 마이크로파일의 거동을 합리적으로 예측하는 것으로 나타났다.

In this study, a series of centrifuge tests were performed in order to observe the bearing capacity of waveform micropile, a new concept of micropile that uses a modified jet grouting process. A total of six models were considered, conventional micropile, jet grouted pile, and four different shapes of waveform micropiles. The test results indicated that the waveform micropile effectively contributes to the increase of the bearing capacity compared to the micropile without the shear keys. Among the waveform micropiles, the model that has a relatively small space between the shear keys showed the most significant improvement of load capacity. Additionally, the ultimate load capacities of all piles were compared using well-known estimation method. As a result, P-S curve method and total settlement method with 25.4 mm were considered suitable to account ultimate load for the waveform micropile.

키워드

참고문헌

  1. Balign, F. A. and Abdelrahman, G. E. (2005), "Modification of Davisson's Method", Proc. of the International Conference on Soil Mechanics & Geotechnical Engineering. Vol.16, No.4, pp.2079-2082.
  2. Davisson, M. T. (1972), "High Capacity Piles. Proceedings, Lecture Series, Innovations in Foundation Construction", ASCE, Illinois Section, Chicago, pp.81-112.
  3. FHWA (2005), Micropile Design and Construction: Reference Manual, FHWA-NHI-05-039, Federal Highway Administration, Vol.1, No.1, pp.7-28.
  4. Finno, R. J. (2002), "Evaluation of Capacity of Micropiles Embedded in Dolomite:, Final Rep. of Infrastructure Technology Institute, Northwestern Univ., Evanston, IL.
  5. Gomez. J., Cadden, A., and Bruce, D. A. (2003), "Micropiles Founded in Rock: Development and Evolution of Bond Stresses under Repeated Loading", Proc. of the 12th Pan-American Conferemce on Soil Mechanics and Geotechnical Engineering (Soil Rock America 2003), VGE, Essen, Germany, pp.1911-1916.
  6. Han, J. T., Kim, S. R., Jang. Y. E., and Lee, S. H. (2013), "Evaluation of Bearing Capacity of Waveform Micropile by Numerical Analyses", Journal of the Korea Academia-Industrial cooperation Society, Vol.14, No.11, pp.5906-5914. https://doi.org/10.5762/KAIS.2013.14.11.5906
  7. Jaritngam, S. (2003), "Design Concept of Soil Improvement for Road Construction on Soft Clay", In Proceedings of the eastern Asia society for transportation studies, Vol.4, pp.311-322.
  8. Juran, I., Benslimane, A., and Hanna, S. (2001), Engineering analysis of dynamic behavior of micropile systems, Transportation Research Record No. 1772: Soil Mechanics, pp.91-106.
  9. Kim, D. S., Kim, N. R., Choo, Y. W., and Cho, G. C. (2013), "A Newly Developed State-of-the-art Geotechnical Centrifuge in Korea", Journal of Korean Society of Civil Engineering, Vol.17, No.1, pp.77-84.
  10. Lee, J. M. and Kim, D. H. (2014), "A Bearing Capacity of Micropile with Expanded Drill Hole", Journal of Korean Society of Hazard Mitigation, Vol.14, No.4, pp.127-133. https://doi.org/10.9798/KOSHAM.2014.14.4.127
  11. Sadek, M. and Isam, S. (2004), "Three-dimensional Finite Element Analysis of the Seismic behavior of Inclined Micropiles", Soil Dynamics and Earthquake Engineering, Vol.24, No.6, pp.473-485. https://doi.org/10.1016/j.soildyn.2004.02.002
  12. Seo, H., Prezzi, M., and Salgado, R. (2013), "Instrumented Static Load Test on Rock-Socketed Micropile", Journal of Geotechnical and Geoenvironmental Engineering, Vol.139, No.12, pp.2037-2047. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000946
  13. Terzaghi, K. and Peck, R. B. (1967), Soil Mechanics in Engineering Practice, 2nd ed, John Wiley and Sons, New York, pp.346-352.
  14. Tornaghi, R. and Cippo, A. P. (1985), "Soil Improvement by Jet Grouting for the Solution of Tunnelling Problems", Proc. of the 4th International Symposium Tunnelling. Vol.85, pp.1-10.
  15. Touma, F. T. and Reese, L. C. (1974), "Behavior of Bored Piles in Sand", Journal Geotechnical Engineering Division, ASCE, Vol.100, No.7, pp.749-761.
  16. Tsukada, K., Miura, Y., Tsubokawa, Y., and Otani., G. L. (2006), "Mechanism of Bearing Capacity of Spread Footings Reinforced with Micropiles", Journal of soils and foundations, Vol.46, No.3, pp.367-376. https://doi.org/10.3208/sandf.46.367