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원심모형실험을 이용한 무리말뚝의 동적 p-y 곡선 산정

Evaluation of Dynamic p-y Curves of Group Piles Using Centrifuge Model Tests

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  • 김성렬 (서울대학교 건설환경공학부)
  • 투고 : 2018.03.28
  • 심사 : 2018.05.17
  • 발행 : 2018.05.31

초록

무리말뚝의 내진설계를 수행할 때 지반-말뚝 동적상호작용을 고려하는 것이 중요하다. 특히, 동적하중을 받는 무리말뚝의 횡방향 저항력은 무리말뚝 효과에 의하여 단일말뚝과 비교하여 감소한다. 그러나, 지금까지 지진하중을 받는 무리말뚝의 동적 무리말뚝 효과를 제안한 연구는 매우 부족한 실정이다. 그러므로, 본 연구에서는 건조 모래지반에 설치된 $3{\times}3$ 무리말뚝에 대한 동적 원심모형실험을 수행하여 무리말뚝 효과를 산정하였다. 이 무리말뚝 효과는 동적 p-y 곡선에서 극한 횡방향 지반반력과 지반반력계수에 대한 보정계수(multiplier)를 적용하여 고려하였다. 그리고, 본 연구에서 얻어진 동적 p-y 곡선을 Beam on Nonlinear Winkler Foundation 모델을 이용한 비선형 동해석에 적용하여 그 적용성을 검증하였다. 그 결과, 본 연구에서 제안한 무리말뚝의 보정계수가 원심모형실험 결과를 잘 모사할 수 있는 것으로 나타났다.

Dynamic soil-pile interaction is the main concern in the design of group piles under earthquake loadings. The lateral resistance of the pile group under dynamic loading becomes different from that of a single pile due to the group pile effect. However, this aspect has not yet been properly studied for the pile group under seismic loading condition. Thus, in this study the group pile effect was evaluated by performing a series of dynamic centrifuge tests on $3{\times}3$ group pile in dry loose sand. The multiplier coefficients for ultimate lateral resistance and subgrade reaction modulus were suggested to obtain the p-y curve of the group pile. The suggested coefficients were verified by performing the nonlinear dynamic analyses, which adopted Beam on Nonlinear Winkler Foundation model. The predicted behavior of the pile group showed the reasonable agreement compared with the results of the centrifuge tests under sinusoidal wave and artificial wave.

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참고문헌

  1. American Association of State Highway and Transportation Officials (AASHTO) (2012), AASHTO LRFD Bridge Design Specifications, 6th ed, Washington, DC.
  2. American Petroleum Institute (API) (2000), Recommended Practices for Planning, Designing and Constructing Fixed Offshore Platforms, API recommendation practice 2A (RP 2A), 21th edn.
  3. Boulanger, R.W., Curras, C.J., Kutter, B.L., Winson, D.W., and Abghari, A. (1999), "Seismic Soil-Pile-Structure Interaction Experi- ments and Analyses", Journal of Geotechnical and Geoenvironmental Engineering, Vol.125, No.9, pp.750-759. https://doi.org/10.1061/(ASCE)1090-0241(1999)125:9(750)
  4. Brandenberg, S.J., Wilson, D.W., and Rashid, M. (2010), "Weighted Residual Numerical Differentiation Algorithm Applied to Experimental Bending Moment Data", Journal of Geotechnical and Geoenvironmental Engineering, Vol.136, No.6, pp.854-863. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000277
  5. Brown, D., Morrison, C., and Reese, L.C. (1988), "Lateral Load Behavior of Pile Group in Sand", Journal of Geotechnical and Geoenvironmental Engineering, Vol.114, No.11, pp.1261-1276. https://doi.org/10.1061/(ASCE)0733-9410(1988)114:11(1261)
  6. Dou, H. and Byrne. P. (1996), "Dynamic Response of Single Piles and Soil-Pile Interaction", Canadian Geotechnical Journal, Vol.33, No.1, pp.80-96. https://doi.org/10.1139/t96-025
  7. EL Naggar, M. and Novak, M. (1996), "Nonlinear Analysis for Dynamic Lateral Pile Response", Soil Dynanmic and Earthquake Engineering, Vol.15, No.4, pp.233-244. https://doi.org/10.1016/0267-7261(95)00049-6
  8. Fayyazi, S., Taiebat, M., and Finn, W. (2014), "Group Reduction Factors for Analysis of Laterally Loaded Pile Groups", Canadian Geotechnical Journal, Vol.51, pp.758-769. https://doi.org/10.1139/cgj-2013-0202
  9. Gerolymos, N., Escoffier, S., Gazetas, G., and Garnier, J. (2009), "Numerical Modeling of Centrifuge Cyclic Lateral Pile Load Experiments", Earthquake Engineering and Engineering Vibration, Vol.8, No.1, pp.61-76. https://doi.org/10.1007/s11803-009-9005-8
  10. Haiderali, A.E. and Madabhushi, G. (2016), "Evaluation of Curve Fitting Techniques in Deriving p-y Curves for Laterally Loaded Piles", Geotechnical and Geological Engineering, Vol.34, No.5, pp.1453-1473. https://doi.org/10.1007/s10706-016-0054-2
  11. Khari, M., Kassim, K.A., and Adnan, A. (2014), "Development of p-y Curves of Laterally Loaded Piles in Cohesionless Soil", The Sciencetific World Journal, Vol.2014, pp.9171741-9171748.
  12. Kim, S.R., Kim, S.H., Chung, C.K., and Kim, M.M. (2002), "The Evaluation of Dynamic Group Pile Effect by the Analysis of Experimental p-y Curves", Journal of The Korean Geotechnical Society, Vol.18, No.1, pp.127-132. (in Korean)
  13. Kondner, R.L. (1963), "Hyperbolic Stress-Strain Response:Cohesive Soils", Journal of Soil Mechanics and Foundation Division, ASCE, Vol.87, No.1, pp.115-144.
  14. Madabhushi, G. (2014), Centrifuge Modelling for Civil Engineering.
  15. Matlock, H. (1970), "Correlations for Design of Laterally Loaded Piles in Soft Clay", In: Proceeding of the 2nd annual offshore technology conference, Vol 1, Houston, Texas, pp.577-594.
  16. McVay, M., Casper, R., and Shang, T. (1998), "Centrifuge Testing of Large Laterally Loaded Pile Groups in Sands", Journal of Geotechnical and Geoenvironmental Engineering, Vol.124, No.10, pp.1016-1026. https://doi.org/10.1061/(ASCE)1090-0241(1998)124:10(1016)
  17. Mezazigh, S. and Levacher, D. (1998), "Laterally Loaded Piles in Sand: Slope Effect on p-y Reaction Curves", Canadian Geotechnical Journal, Vol.35, pp.433-441. https://doi.org/10.1139/t98-016
  18. Ministry of Land, Infrastructure and Transport (1999), Korean Seismic Design Guideline (in Korean).
  19. Murchinson, J.M. and O'Neill, M.W. (1984), "Elevation of p-y Relationships in Cohesionless Soils", In: Meyer JR (ed) Analysis Design Pile Foundation. ASCE, New York, pp.174-191.
  20. National Cooperative Highway Research Program (2001), Static and Dynamic Lateral Loading of Pile Groups, NCHRP Rept 461, Transportation Res Board - Natl Res Council, pp.13-21.
  21. Opensees Command Language Manual (2007).
  22. Reese, L.C., Cox, W.R., and Koop, F.D. (1974), "Analysis of Laterally Loaded Piles in Sand", Proc. of the 6th Offshore Technology Conference, Paper 2080, Houston, Texas, pp.473-483.
  23. Reese, L.C. and Van Impe, W.R. (2001), Single Piles and Pile Groups under Lateral Loading, Balkema, Rotterdam.
  24. Wilson, D.W. (1998), Soil-Pile-Superstructure Interaction in Liquefying Sand and Soft Cay. Ph.D. Dissertation, University of California at Davis.
  25. Yang, E.K., Choi, J.I., Han, J.T., and Kim, M.M. (2010), "Evaluation of Dynamic Group Pile Effect in Sand by 1g Shaking Table Tests", ournal of The Korean Geotechnical Society, Vol.26, No.8, pp.77-88. (in Korean).
  26. Yang, E.K., Jeong, S., Kim, J.H., and Kim, M.M. (2011), "Dynamic p-y Backbone Curves from 1g Shaking Table Tests", KSCE Journal of Civil Engineering, Vol.15, No.5, pp.813-821. https://doi.org/10.1007/s12205-011-1113-0
  27. Yoo, M.T., Cha, S.H., Kim, M.M., Choi, J.I., and Han, J.T. (2012), "Evaluation of Dynamic Group-Pile Effect in Dry Sand by Centrifuge Model Tests", International Joural of Offshore and Polar Engineering, Vol.22, No.2, pp.165-171.
  28. Yoo, M.T., Choi, J.I., Han, J.T., and Kim, M.M. (2013), “Dynamic p-y Curves for Dry Sand by Dynamic Centrifuge Tests”, Journal of Earthquake Engineering, Vol.17, No.7, pp.1082-1102. https://doi.org/10.1080/13632469.2013.801377