Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
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Parametric Study of Dynamic Soil-pile-structure Interaction in Dry Sand by 3D Numerical Model

3차원 수치 모델을 이용한 건조사질토 지반-말뚝-구조물 동적 상호작용의 매개변수 연구

  • Kwon, Sun-Yong (Div. of Construction Technology, Samsung C&T) ;
  • Yoo, Min-Taek (Advanced Infrastructure Research Team, Korea Railroad Research Institute)
  • Received : 2016.07.20
  • Accepted : 2016.08.30
  • Published : 2016.09.30
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Abstract

Parametric studies for various site conditions by using 3d numerical model were carried out in order to estimate dynamic behavior of soil-pile-structure system in dry soil deposits. Proposed model was analyzed in time domain using FLAC3D which is commercial finite difference code to properly simulate nonlinear response of soil under strong earthquake. Mohr-Coulomb criterion was adopted as soil constitutive model. Soil nonlinearity was considered by adopting the hysteretic damping model, and an interface model which can simulate separation and slip between soil and pile was adopted. Simplified continuum modeling was used as boundary condition to reduce analysis time. Also, initial shear modulus and yield depth were appropriately determined for accurate simulation of system's nonlinear behavior. Parametric study was performed by varying weight of superstructure, pile length, pile head fixity, soil relative density with proposed numerical model. From the results of parametric study, it is identified that inertial force induced by superstructure is dominant on dynamic behavior of soil-pile-structure system and effect of kinematic force induced by soil movement was relatively small. Difference in dynamic behavior according to the pile length and pile head fixity was also numerically investigated.

다양한 현장 조건에서 일어날 수 있는 건조토 지반-말뚝-구조물 시스템의 동적거동을 평가하고 고찰하기 위해 3차원 수치 모델을 이용한 매개변수 연구가 수행되었다. 강진 시 지반의 비선형 거동을 적절하게 모사하기 위해 상용 유한 차분 프로그램인 FLAC3D를 통해 시간 영역에서 이루어졌다. 지반 구성 모델은 Mohr-Coulomb 탄소성 모델을 적용하였으며 지반 전단 탄성 계수의 비선형적인 감소를 모사할 수 있는 이력 감쇠 모델을 적용하였다. 진동 시 지반-말뚝 간의 완전 접촉, 미끄러짐, 분리 현상을 모두 모사하는 경계요소 모델을 적용하였으며 경계 조건의 경우, 지반-말뚝 상호작용의 영향을 받는 근역 지반만 메쉬를 생성하고 근역 지반의 경계부에 원역 지반의 가속도-시간 이력을 입력하는 방식인 단순화 연속체 모델링 기법을 적용함으로써 해석 효율을 증가시키고자 하였다. 또한, 적절한 최대지반탄성계수와 항복 깊이의 설정으로 지반의 비선형 거동을 더욱 정확히 모사하고자 하였다. 개발된 수치 모델을 이용하여 상부질량의 크기, 말뚝의 길이, 두부 경계조건, 지반의 상대밀도에 대한 매개변수 연구를 수행함으로써 다양한 현장 조건에 대한 지반-말뚝-구조물 시스템의 동적 거동을 평가하였다. 매개변수 연구 결과, 건조토 지반 조건에서는 상부질량에 의한 관성력이 시스템의 동적 거동에 지배적인 영향을 미침을 확인하였으며 지반에 의한 운동력의 영향은 상대적으로 적다고 평가되었다. 또한 짧은 말뚝과 긴 말뚝의 동적 거동 차이 및 말뚝두부 고정단과 자유단의 거동 차이를 해석적으로 검증하였다.

Keywords

References

  1. Broms, B. B. (1965), "Design of Laterally Loaded PIles", In Proceedings: ASCE Journal of Soil Mechanics and Foundations Div., 91, pp.79-99.
  2. Boulanger, R.W. and Curras, C.J. (1999), "Seismic Soil-Pile-Structure Interaction Experiments and Analyses", Journal of Geotechnical and Geoenvironmental Engineering, American Society of Civil Engineers, Vol.125, No.9, pp.750-759. https://doi.org/10.1061/(ASCE)1090-0241(1999)125:9(750)
  3. Chang, D.W., Lin, B.S., and Cheng, S.H. (2007), "Dynamic Pile behaviors Affecting by Liquefaction from EQWEAP Analysis," In Proceedings: 4th International conference on earthquake geotechnical engineering, Thessaloniki, Greece; pp.1336.
  4. Cheng, Z. H. and Jeremic, B. (2009), "Numerical Modeling and Simulation of Pile in Liquefiable Soil", Soil Dynamics and Earthquake Engineering, 29, pp.1404-1416.
  5. Comodromos, E. M., Papadopoulou, M. C., and Rentzepris, I. K. (2009), "Pile Foundation Analysis and Design Using Experimental Data and 3-D Numerical Analysis", Computers and Geotechnics, 36, pp.819-836. https://doi.org/10.1016/j.compgeo.2009.01.011
  6. Das, B. M. (2010), Geotechnical Engineering Handbook. J. Ross Publishing.
  7. Hardin, B. O. and Drnevich, V. P. (1972), "Shear Modulus and Damping in Soils: Design Equations and Curves", Journal of the Soil Mechanics and Foundations Division, ASCE, Vol.98, No.SM7, July 1972, pp.667-692.
  8. Ishihara, K. (1997), "Terzaghi Oration: Geotechnical Aspects of the 1995 Kobe Earthquake", In Precedeeings: ICSMFE, Hamburg, pp.2047-2073.
  9. Itasca Consulting Group (2006), FLAC3D (Fast Lagrangian Analysis of Continua in 3Dimensions) User's Guide, Minnesota, USA.
  10. Kim, S. H., Kwon, S. Y., Kim, M. M., and Han, J. T. (2012), "3D Numerical Simulation of a Soil-Pile System Under Dynamic Loading", Marine Georesources & Geotechnology, 30(4), pp.347-361. https://doi.org/10.1080/1064119X.2012.657997
  11. Kuhlemeyer, R. L., and Lysmer, J. (1973), "Finite Element Method Accuracy for Wave Propagation Problems", Journal of Soil Mechanics & Foundations Div, 99 (Tech Rpt).
  12. Kumar, J. and Madhusudhan, B. N. (2010), "Effect of Relative Density and Confining Pressure on Poisson Ratio from Bender and Extender Elements Tests", Geotechnique, Vol.60, No.7, pp.561-567. https://doi.org/10.1680/geot.9.T.003
  13. Kwon, S. Y., Kim, S. J., and Yoo, M. T. (2016), "Numerical Simulation of Dynamic Soil-Pile Interaction for Dry Condition Observed in Centrifuge Test", Journal of the Korean Geotechnical Society, Vol.32, No.4, pp.5-14. https://doi.org/10.7843/kgs.2016.32.4.5
  14. Liyanapathirana, D. S. and Poulos, H. G. (2010), "Analysis of Pile behaviour in Liquefying Sloping Ground", Computers and Geotechnics, Vol.37, No.1, pp.115-124. https://doi.org/10.1016/j.compgeo.2009.08.001
  15. Martin, G. R. and Chen, C. Y. (2005), "Response of Piles due to Lateral Slope Movement", Computers and Structures, Vol.83, pp.588-598. https://doi.org/10.1016/j.compstruc.2004.11.006
  16. Matlock, H. and Reese, L. C. (1962), "Generalized Solutions for Laterally Loaded Piles", Journal of the Soil Mechanics and Foundations Division, ASCE, Vol.86, No.5, pp.63-91.
  17. Miwa, S., Ikeda, T., and Sato, T. (2006), "Damage Process of Pile Foundation in Liquefied Ground during Strong Ground Motion", Soil Dynamics and Earthquake Engineering, Vol.26, No.2, pp.325-336. https://doi.org/10.1016/j.soildyn.2005.05.001
  18. Nogami, T., Otani, J., Konagai, K., and Chen, H. (1992), "Nonlinear Soil-pile Interaction Model for Dynamic Lateral Motion", Journal of Geotechnical Engineering, Vol.118, No.1, pp.89-106. https://doi.org/10.1061/(ASCE)0733-9410(1992)118:1(89)
  19. Prakash, S. and Agarwal, S. L. (1967), "Effect of Pile Embedement on Natural Frequency of Foundations", In Proceeding: First Southeast Asian Conference on Soil Mechanics and Foundation Engineering, Bankok, pp.333-336.
  20. Tahghighi, H. and Konagai, K. (2007), "Numerical Analysis of Nonlinear Soil-pile Group Interaction under Lateral Loads", Soil Dynamics and Earthquake Engineering, Vol.27, No.5, pp.463-474. https://doi.org/10.1016/j.soildyn.2006.09.005
  21. Uzuoka R., Sento N., and Kazama M. (2007), "Three-dimensional Numerical Simulation of Earthquake Damage to Group-piles in a Liquefied Ground", Soil Dyn Earthquake Eng, 27, pp.395-413. https://doi.org/10.1016/j.soildyn.2006.10.003
  22. Wang, S., Kutter, B. L., Chacko, M. J., Wilson, D. W., Boulanger, R. W., and Abghari, A. (1998), "Nonlinear Seismic Soil-pile Structure Interaction", Earthquake spectra, Vol.14, No.2, pp.377-396. https://doi.org/10.1193/1.1586006
  23. Yang, E. K. (2009), "Evaluation of Dynamic p-y Curves for a Pile in Sand from 1g Shaking Table Tests", Ph. D. Dissertation, Seoul National University, South Korea.
  24. Yoo, M. T., Choi, J. I., and Han, J. T. (2013), "Dynamic P-Y Curves for Dry Sand from CentrifugeTests", Journal of Earthquake Engineering, Vol. 17, pp. 1082-1102. https://doi.org/10.1080/13632469.2013.801377

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