Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
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A Study on the Dynamic p-y Curves in Soft Clay by 1 g Shaking Table Tests

1g 진동대 실험을 이용한 연약 점성토 지반에서의 동적 p-y 곡선 연구

  • Han, Jin-Tae (Dept. of Civil & Environmental Engrg., Seoul National Univ.) ;
  • Yoo, Min-Taek (Dept. of Civil & Environmental Engrg., Seoul National Univ.) ;
  • Choi, Jung-In (Dept. of Civil & Environmental Engrg., Seoul National Univ.) ;
  • Kim, Myoung-Mo (Dept. of Civil & Environmental Engrg., Seoul National Univ.)
  • 한진태 (서울대학교 건설환경공학부) ;
  • 유민택 (서울대학교 건설환경공학부) ;
  • 최정인 (서울대학교 건설환경공학부) ;
  • 김명모 (서울대학교 건설환경공학부)
  • Received : 2010.06.18
  • Accepted : 2010.07.20
  • Published : 2010.08.31
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Abstract

In this study, a series of 1 g shaking table tests were carried out for a single pile in soft clay with various input acceleration amplitudes and frequencies. Based on the results, dynamic p-y curves were drawn and, in turn, the dynamic p-y backbone curve was formed by connecting the peak points, corresponding to the maximum soil resistance, of the dynamic p-y curves. In order to represent the p-y backbone curve numerically, Matlock's p-y formulations for clay was used to find the initial stiffness ($k_{ini}$) and the ultimate capacity ($p_u$) of the clay, both of which are required to formulate the p-y backbone curve as a hyperbolic function. The suggested p-y backbone curve was verified through comparisons with currently available p-y curves as well as other researchers' centrifuge test results and numerical analysis results.

본 연구에서는 연약 점성토 지반에 근입된 모형말뚝을 대상으로 다양한 입력 가속도 크기 및 진동수 조건에서 1g 진동대 실험을 수행하였다. 실험 결과를 이용하여, 각각의 동적 p-y 곡선을 산정하였으며, 이 p-y 곡선 상에서 최대지반반력이 나타나는 꼭지점들을 연결하여 연약 점성토의 동적 p-y 중추곡선(Backbone curve)을 쌍곡선 함수로 나타내었다. 이 쌍곡선 함수를 정의하는데 필요한 초기 기울기와 극한 저항력은 Matlock의 p-y 곡선 공식을 이용하여 제안하였다. 새로 제안한 동적 p-y 중추곡선은 실제 내진설계에 사용되고 있는 정적 p-y 곡선과 다른 연구자들의 원심모형실험 결과 및 수치해석 결과와 비교하여 검증하였다.

Keywords

References

  1. 양의규 (2009), Evaluation of dynamic p-y curves for a pile in sand from 1g shaking table tests, 박사학위논문, 서울대학교
  2. 윤종구, 김동수, 유제남 (2003), "지중구조물의 내진설계를 위한 기반면의 속도응답 스펙트럼 및 응답변위 산정기법에 대한 연구", 한국지반공학회 논문집, 제19권, 제4호, pp.149-155.
  3. 한국지반공학회 (2006), "지반구조물의 내진설계", 구미서관, pp. 278-287.
  4. American Petroleum Institute (API) (1987), Recommended practice for planning, Designing and constructing fixed offshore platforms, API Recommendation Practice 2A (RP 2A), 17th edition.
  5. Boulanger, R.W., Curras, C.J., Kutter, B.L., Wilson, D.W., and Abghari, A. (1999), "Seismic soil-pile-structure interaction experiments and analyses", Journal of Geotechnical and Geoenvironmental Engineering, Vol.125, No.9, pp.750-759.
  6. Dou, H., and Byrne, P.M. (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. Iai, S. (1989), "Similitude for shaking table tests on soil-structurefluid model in 1g gravitational field", Soils and Foundations, Vol.29, No.1, pp.105-118. https://doi.org/10.3208/sandf1972.29.105
  8. Janbu, N. (1963), "Soil compressibility as determined by oedometer and triaxial test", Proceedings of the European Conference on Soil Mechanics and Foundations Engineering, Wiesbadan, Germany, Vol.1, pp.19-25.
  9. Kondner, R.L. (1963), "Hyperbolic stress-strain response: Cohesive soils", J. Soil Mechanics and Foundations Div., Vol.89, No.1, pp. 115-144.
  10. Lefebvre, G., and LeBoeuf, D. (1987), "Rate effects and cyclic loading of sensitive clays", Journal of Geotechnical and Geoenvironmental Engineering, Vol.113, No.5, pp.476-489. https://doi.org/10.1061/(ASCE)0733-9410(1987)113:5(476)
  11. Matesic, L., and Vucetic, M. (2003), "Strain-Rate effect on soil secant shear modulus at small cyclic strains", Journal of Geotechnical and Geoenvironmental Engineering, Vol.129, No.6, pp. 536-549. https://doi.org/10.1061/(ASCE)1090-0241(2003)129:6(536)
  12. Matlock, H. (1970), "Correlations for design of laterally loaded piles in soft clay", Proceeding of Offshore Technology Conference, Houston, Texas, pp.577-594.
  13. Meymand, P.J. (1998), Shaking table scale model tests of nonlinear Soil-Pile-Superstructure interaction in soft clay, Ph.D. Dissertation, University of California, Berkeley
  14. Reese, L.C., Cox, W.R., and Koop, F.D. (1975), "Field testing and analysis of laterally loaded piles in stiff clay", Proceeding of Offshore Technology Conference, Houston, Texas, pp.671-690.
  15. Rovithis, E., Kiratas, E., and Pitilakis, K. (2009), "Experimental p-y loops for estimating seismic soil-piile interaction", Bull Earthquake Engineering, Vol.7, pp.719-736. https://doi.org/10.1007/s10518-009-9116-7
  16. Ting, J.M., Kauffman, C.R., and Lovicsek, M. (1987), "Centrifuge static and dynamic lateral pile behavior", Canadian Geotechnical Journal, Vol.24, pp.198-207. https://doi.org/10.1139/t87-025