Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
권호 표지
DOI QR코드

DOI QR Code

Numerical Analysis of Dynamic Centrifuge Model Tests Using an Effective Stress Model

유효응력모델을 이용한 동적 원심모형실험의 수치해석

  • Park Sung-Sik (Geoenvironment Group, Klohn Crippen Consultants Ltd.) ;
  • Kim Young-Su (Dept. of Civil Engrg., Kyungpook National Univ.)
  • Published : 2006.01.01
Download PDF
⟨ Previous Next ⟩

Abstract

In this study an effective stress numerical procedure is used to assess the results of dynamic centrifuge tests under high effective stress. The centrifuge models consist of loose Nevada sand with an initial vertical effective stress of 380kPa at depth, and they are modeled as a one-dimentional soil column. Liquefaction occurred up to 37m or 22m at depth, and the onset of liquefaction triggering was opposite to the conventional liquefaction evaluation procedure. In other words, liquefaction occurs first at the top and propagates downward as shaking continues. The results observed in centrifuge tests are reasonably predicted by the effective stress model. It is noted that the degree of initial saturation and additional densification at depth arising from the application of the high acceleration field play a key role in capturing the results of dynamic centrifuge tests.

본 연구에서는 비교적 높은 초기 유효응력을 가진 지반구조물의 액상화연구에 사용된 동적 원심모형실힘결과를 이용하여 유효응력모델검증에 관한 연구를 수행하였다. 원심모형 지반은 최대 유효응력 380kPa를 가진 충분히 포화된 느슨한 Nevada 모래 지반으로 구성되었으며, 수치해석에서는 1차원의 기둥형태로 가정하였다. 수치해석에 이용한 두 종류의 원심모형실험에서는 상당한 깊이(37m 및 22m)까지도 액상화가 발생하였으나, 깊이에 따른 액상화발생 경향은 경험적 액상화 평가방법과 상반된 결과를 보였다. 즉, 원심모형실험에서 계측된 과잉간극수압을 기준으로 해석하였을 때, 액상화는 모형지반의 윗부분에서 먼저 발생한 후 점차적으로 아랫부분으로 이동함을 알았다. 이와 같은 실험결과는 수치해석에서 비교적 잘 예측된 것으로 판단되었다 원심모형 지반의 초기 포화도와 원심력 증가에 따른 지반의 상대밀도 증가가 액상화모형실험의 수치해석에서 중요한 역할을 함을 알 수 있었다.

Keywords

References

  1. 박성식, 김영수, Byrne, P.M., 김대만 (2005), '액상화해석을 위한 간단한 구성모델', 한국 지반공학회 논문집, 제21권, 8호, pp.27-35
  2. Arulanandan, K. and Scott, R.F. (1993), Verification of numerical procedures for the analysis of soil liquefaction problems, Proceedings of the International Conference on the Verification of Numerical Procedures for the Analysis of Soil Liquefaction Problems, Vols.1 and 2, Balkema, Rotterdam, the Netherlands
  3. Arulmoli, K., Muraleetharan, K.K., Hosain, M.M., and Fruth, L.S. (1992), VELACS laboratory testing program, soil data report. The Earth Technology Corporation, Irvine, California, Report to the National Science Foundation, Washington D.C., March
  4. Chern, J.C. (1985), Undrained response of saturated sands with emphasis on liquefaction and cyclic mobility, Ph.D Thesis, The University of British Columbia, Canada
  5. Dewoolkar, M.M., Ko, H.-Y., Stadler, A.T., and Astaneh, S.M.F (1999), 'A substitute pore fluid for seismic centrifuge modeling', Geotechnical Testing Journal, Vol.22, No.3, pp.196-210 https://doi.org/10.1520/GTJ11111J
  6. Gonzalez, L, Abdoun, T., and Sharp, M.K. (2002), 'Modeling of seismically induced liquefaction under high confining stress', International Journal of Physical Modelling in Geotechnics, Vol.2, No.3, pp.1-15 https://doi.org/10.1680/ijpmg.2002.2.4.01
  7. Hausler, E.A. and Sitar, N. (2001), 'Performance of soil improvement techniques in earthquakes', In Proceedings of the Fourth International Conference on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics. Paper No. 10.15
  8. Ishihara, K., Tsuchiya, H., Huang, Y., and Kamada, K. (2001), 'Recent studies on liquefaction resistance of sand-Effect of saturation', Proceedings of the Fourth International Conference on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics, San Diego, California, March 26-31, 2001
  9. Itasca Consulting Group Inc. (2000), FLAC, version 4.0. Itasca Consulting Group Inc., Minneapolis
  10. Kammerer, A., Wu, J., Pestana, J., Riemer, M., and Seed, R. (2000), Cyclic simple shear testing of Nevada sand for PEER Center project 2051999. Geotechnical Engineering Research Report No. UCB/GT/00-01, University of California, Berkeley, January
  11. Lade, P.V. (2005), 'Overview of constitutive models for soils'. Calibration of constitutive models, Geotechnical Special Publication, No. 139, ASCE
  12. Negussey, D., Wijewickreme, D., and Vaid, Y.P. (1988), 'Constant volume friction angle of granular materials', Canadian Geotechnical Journal, Vol.25, No.1, pp.50-55 https://doi.org/10.1139/t88-006
  13. Park, S.-S. (2005), 'A Two Mobilized-plane model and its application for soil liquefaction analsysis', Ph.D Thesis, The University of British Columbia, Canada (http://www.geomaths.com)
  14. Park, S.-S. and Byrne, P.M. (2004), 'Stress densification and its evaluation', Canadian Geotechnical Journal, Vol.41, pp.181-186 https://doi.org/10.1139/t03-076
  15. Park, S.-S., Sharp, M.K., and Byrne, P.M. (2004), 'The influence of stress densification and centrifuge model preparation method for soil liquefaction', Proceedings of the Fifty Seventh Canadian Geotechnical Conference, 24-27 October 2004, Quebec City, Quebec, Canada
  16. Puebla, H., Byrne, P.M., and Phillips, R. (1997), 'Analysis of CANLEX liquefaction embankments: prototype and centrifuge models', Candian Geotechnical Journal, Vol.34, No.5, pp.641-657 https://doi.org/10.1139/cgj-34-5-641
  17. Seed, H. B. and Idriss, I. M. (1971), 'Simplified procedure for evaluating soil liquefaction potential', Journal of the Soil Mechanics and Foundations Division, ASCE, Vol.97, No.SM9, pp.1249-1273
  18. Seed, H. B., Wong, R. T., Idriss, I. M., and Tokimatsu, K. (1986), 'Moduli and damping factors for dynamic analyses of cohesionless soils', Journal of Geotechnical Engineering, ASCE, Vol.112, No.11, pp.1016-1032 https://doi.org/10.1061/(ASCE)0733-9410(1986)112:11(1016)
  19. Skempton, A.W. (1986), 'Standard penetration test procedures and the effects in sands of overburden pressure, relative density, particle size, ageing and overconsolidation', Geotechnique, Vol.36, No.3, pp.425-447 https://doi.org/10.1680/geot.1986.36.3.425
  20. Taylor, D.W. (1948), Fundamentals of Soil Mechanics, John Wiley and Sons, New York
  21. Youd, T.L., Idriss, I.M., Andrus, R.D., Arango, I., Castro, G., Christian, J.T., Dobry, R., Finn, W.D.L., Harder Jr., L.F., Hynes, M.E., Ishihara, K., Koester, J.P., Liao, S., Marcuson III, W.F., Martin, G.R., Mitchell, J.K., Moriwaki, Y., Power, M.S., Robertson, P.K., Seed, R.B. and Stokoe, K.H. (2001), 'Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER and 1998 NCEER/NSF Workshops on Evaluation of Liquefaction Resistance of Soils', Journal of Geotechnical and Geoenvironmental Engineering, Vol.127, No.10, pp.817-833 https://doi.org/10.1061/(ASCE)1090-0241(2001)127:10(817)
  22. Xia, H. and Hu, T. (1991), 'Effects of saturation and back pressure on sand liquefaction', Journal of Geotechnical Engineering, Vol.117, No.9, pp.1347-1362 https://doi.org/10.1061/(ASCE)0733-9410(1991)117:9(1347)