Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
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Characteristics of Undrained Cyclic Shear Behavior for the Nak-dong River Sand Due to the Aging Effect

Aging 효과에 따른 낙동강 모래의 비배수 반복전단거동 특성

  • Kim Dae-Man (Dept. of Civil Engrg., Kyungpook National Univ.) ;
  • Kim Young-Su (Dept. of Civil Engrg., Kyungpook National Univ.) ;
  • Jung Sung-Gwan (Dept. of Landscape Architecture, Kyungpook National Univ.) ;
  • Seo In-Shik (Dept of Civil Engrg., Kyungdong College of Techno-information)
  • Published : 2005.10.01
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Abstract

It was known that the aging effect of sands is insignificant in comparison with clays, and hence the study on this effect had seldom been performed prior to the early 1980s. However, field tests for this effect have been actively carried out since it was investigated that penetration resistance of reformed sands increased with the lapse of time. Recently, the aging effect of sands has also been examined in laboratory testings. In this study, undrained static triaxial tests were performed to evaluate the effect on the Nak-dong River sands, with different .elative densities $(D_r)$, consolidation stress ratios $(K_c)$, and consolidation times. As a result of the tests, it was proved that the undrained cyclic shear strength $(R_f)$ increased with the aged time on the sands. The in situ range of Rf on the sands, which is applicable to the magnitude of earthquake in the Nak-dong River area, was proposed by using the test results.

모래의 aging현상은 점성토에 비하여 무시할 정도로 매우 작아서 1980년대 초까지는 거의 연구되지 않았다. 그러나 퇴적이나 교란 후 시간경과에 따라 관입저항치의 증가가 관찰되면서 현장시험을 중심으로 모래의 aging 효과에 대하여 활발한 조사가 이루어졌고, 최근에는 현장시험뿐만 아니라 실내시험에서도 여러 연구자들에 의해 모래의 aging 효과가 규명되어지고 있다. 본 연구에서는 모래의 비배수 반복전단거동에 대한 aging효과를 살펴보기 위해 낙동강 모래를 이용하여 상대밀도$(D_r)$, 압밀응력비$(K_c)$ 그리고 압밀시간을 달리하여 비배수 반복삼축압축시험을 실시하였다. 시험결과, 비배수 반복전단강도$(R_f)$는 압밀시간에 따라 증가한다는 사실을 확인할 수 있었다. 본 시험결과에서 나타난 aging 에 따른 $R_f$ 증가율을 이용하여 낙동강 모래지반의 지진규모별 비배수 반복전단강도의 현장적용 범위를 제안하였다.

Keywords

References

  1. 김영수, 김대만 (2004), 'Aging 효과에 따른 모래의 비배수 정적전단거동 특성', 한국지반공학회논문집, 제 20권,6호 pp.137-150
  2. Alarcon-Guzman, A., Leonards, G.A. and Chameau, J.L. (1988), 'Undrained monotonic and cyclic strength of sands', Jour. of the Geotechnical Eng. Div., ASCE, Vol.14, No.10, pp.1089-1109
  3. Anderson, D. G. and Stokoe, K. H. (1978), 'Shear modulus: a time dependant soil properly', Dynamic Geotechnical Testing, ASTM STP654, American Society for Testing and Materials, pp.66-90
  4. Castro, G. and Poulos, S. J. (1977), 'Factors affecting liquefaction and cyclic mobility', Jour. of the Geotechnical Eng. Div., ASCE, Vol.103, No.GT6, pp.501-516
  5. Charlie, W. A. (1992), 'Time dependant cone penetration resistance due to blasting', Jour. of Geotechnical Eng. Div., ASCE, Vol.118, No.8, pp.1200-1215 https://doi.org/10.1061/(ASCE)0733-9410(1992)118:8(1200)
  6. Hyodo, M. et al. (1991), 'Undrained cyclic shear strength and resisual shear strain of saturated sand by cyclic triaxial tests', Soils and Foundations, Vol.31, No.3, pp.60-76
  7. Ishihara, K. (1985), 'Stability of natural deposits during earthquakes', SPROC.. 11th into Conf. SMFE, San Francisco, Calif., Vol.1, pp.321-376
  8. Kramer, S. L. (1996), 'Geotechnical earthquake engineering', Prentice-Hall, Inc
  9. Lee, K. L. and Seed, H. B. (1967), 'Dynamic strength of anisotropically consolidated sand', Jour. of Geotechnical Eng. Div., ASCE, Vol.93, No.SM5, pp.169-190
  10. Mesri, G., Feng, T. W., and Benak, J. M. (1990), 'Postdensification penetration resistance of clean sands', Jour. of Geotechnical Eng. Div., ASCE, Vol.116, No.7, pp.1095-1115 https://doi.org/10.1061/(ASCE)0733-9410(1990)116:7(1095)
  11. Mitchell, J. K., and Solymar, Z. V. (1984), 'Time-dependent strength gain in freshly deposited or densified sand', Jour. of Geotechnical Eng. Div., ASCE, Vol.110, No.11, pp.1559-1576 https://doi.org/10.1061/(ASCE)0733-9410(1984)110:11(1559)
  12. Mitchell, J. K. (1986), 'Practical problems from surprising soil behavior', Jour. of Geotechnical Eng. Div., ASCE, Vol.112, No.3, pp.259-289
  13. Mohamad, R., and Dobry, R.. (1986), 'Undrained monotonic and cyclic triaxial strength of sand', Jour. of Geotechnical Eng. Div., ASCE, Vol.112, No.10, pp.941-958 https://doi.org/10.1061/(ASCE)0733-9410(1986)112:10(941)
  14. Rahhal, M. E., Lefebvre, G. (2000), 'Understanding the effect of a static driving shear stress on the liquefaction resistance of medium dense granular soils', Soil Dynamics & Earthquake Engineering, Dec. 20, pp.397-404
  15. Schmertmann, J. H. (1991), 'The mechanical aging of soils', The twenty fifth Carl Terzaghi Lecture, ASCE Journal of Geotechnical Engineering, Vol.117, No.9, pp.1288-1330 https://doi.org/10.1061/(ASCE)0733-9410(1991)117:9(1288)
  16. Seed, H. B. (1979), 'Soil liquefaction and cyclic mobility of evaluation for level ground during earthquakes', Jour. of Geotechnical Eng. Div., ASCE, Vol.105, No.2, pp.201-255
  17. Seed, H. B., Idriss, I. M., and Arango, I. (1983), 'Evaluation of liquefaction potential using field performance data', Jour. of Geotechnical Eng. Div., ASCE, Vol.109, No.3, pp.458-482 https://doi.org/10.1061/(ASCE)0733-9410(1983)109:3(458)
  18. Shozen, T. (2001), 'Deformation under the constant stress state and its effect on stress-strain behaviour of Fraser river sand', M.A.Sc Thesis, The University of British Columbia, Vancouver, Canada
  19. Uchida, K. and Hasegawa, T. (1986), 'Strength-deformation characteristics of a soil subjected to initial shear stress', Soils and Foundations, Vol.26, No.1, pp.11-24
  20. Vaid, Y. P. and Finn, W. D. L. (1979), 'Static shear and liquefaction potential', Jour. of Soil Mechanics and Foundation Div., ASCE, Vol.105, No.GT10, pp.1233-1246
  21. Vaid, Y. P. and Chern, J. C. (1985), 'Cyclic and Monotonic undrained response of sands', Proc. Advanced in the art of testing soils under cyclic loading conditions, Detroit, pp.120-147
  22. Vaid, Y. P. and Thomas, J. (1995), 'Liquefaction and Post liquefaction Behavior of Sand', Jour. of Geotechnical Eng. Div., ASCE, Vol.121, No.2, pp.163-173 https://doi.org/10.1061/(ASCE)0733-9410(1995)121:2(163)
  23. Whitman, R. V., Millar, E. T., and Moore, P. J. (1964), 'Yielding and locking of confined sand', Journal Soil Mech. and Found. Eng. Div., Vol.90, No.4, pp.57-84
  24. Yoshimi, Y. and Ohoka, H. (1975), 'Influence if degree of shear stress reversal on the liquefaction potential of saturated sand', Soils and Foundations, Vol.23, No.1, pp.47-60
  25. Yoshimi, Y. and Tokimatsu, K. (1978), 'Two-dimensional pore pressure changes in sand deposits during earthquakes', 2nd International Conference on Microzonation for Safer Construction, Vol.2, pp.853-863