Journal of the Korean GEO-environmental Society (한국지반환경공학회 논문집)

Korean Geo-Environmental Society (한국지반환경공학회)
권호 표지
DOI QR코드

DOI QR Code

Evaluation of the Influence of the Method of Sample Preparation on the Shearing Behavior of Sands using Elastic Waves

탄성파를 통한 시료성형방법에 따른 모래 전단거동특성 평가

  • Yoo, Jinkwon (Department of Civil and Environmental Engineering, Hanyang University) ;
  • Park, Duhee (Department of Civil and Environmental Engineering, Hanyang University)
  • Received : 2014.02.09
  • Accepted : 2014.04.07
  • Published : 2014.05.01
Download PDF
⟨ Previous Next ⟩

Abstract

For economic and technical reasons, it is difficult to obtain high quality undisturbed cohesionless samples, hence most researchers rely on preparing remolded and reconstituted representative samples of sandy soils. In this study, moist tamping, air pluviation, and dry deposition methods were applied to make remolded samples at similar relative densities. A series of isotropically consolidated drained tests were conducted with accompanied by measured elastic wave velocities in order to evaluate a difference between sample preparation methods and relative densities. For the elastic wave velocity measurements, piezoelectric elements were installed on the top and bottom cap of the triaxial device. The results showed that soil behavior relies on sample preparation methods, and that the trend of shear wave velocity was the same with volumetric strain behavior.

경제적, 기술적인 이유에서 실내시험을 위한 in situ 상태 그대로의 현장 모래 시료를 채취하는 것은 매우 어렵다. 따라서 현장과 유사한 상태의 시료 조성을 위한 다양한 시료 재성형 방법이 제시되었으며, 연구 목적에 따라 적합하다고 판단되는 시료성형방법이 다양하게 적용되고 있다. 본 논문에서는 모래의 시료 재성형 시 널리 이용되고 있는 습윤다짐법, 건조낙사법, 그리고 건조퇴적법을 적용하여 동일한 상대밀도로 시료를 조성한 후, 일정한 구속압 조건에서 압밀배수전단 시험을 수행하였다. 또한 자체제작을 통해 시료의 상 하부 캡에 압전소자를 설치하여 압밀 종료 시점과 전단과정에서의 탄성파 속도를 측정함으로써 시료 재성형 방법 및 상대밀도에 따른 오타와 모래에서의 거동 특성 및 전단거동 시의 탄성파 속도의 변화 경향을 분석하였다. 분석 결과, 시료 조성방법에 따라 전단과정에서 모래의 거동에는 차이가 발생할 수 있는 것으로 나타났으며, 전단과정 시 전단파 속도는 체적 변화양상과 동일한 경향을 보이는 것으로 나타났다.

Keywords

References

  1. Been, K. and Jefferies, M. (1985), State parameter for sands, International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts: Elsevier Science, Vol. 22, No. 6, pp. 198. https://doi.org/10.1016/0148-9062(85)90264-5
  2. Cha, M. and Cho, G. C. (2007), Shear strength estimation of sandy soils using shear wave velocity, ASTM Geotechnical Testing Journal, Vol. 30, No. 6, pp. 484-495.
  3. Cho, K. C. and Lee, I. M. (2002), Soil properties in relation to elastic wave, Journal of the Korean Geotechnical Society, Vol. 18, No. 6, pp. 83-101 (in Korean).
  4. Cresswell, A., Barton, M. E. and Brown, R. (1999), Determining the maximum density of sands by pluviation, ASTM Geotechnical Testing Journal, Vol. 22, No. 4, pp. 324-328. https://doi.org/10.1520/GTJ11245J
  5. Cubrinovski, M. and Ishihara, K. (2001), Correlation between penetration resistance and relative density of sandy soils, 15th International Conference on Soil Mechanics and Geotechnical Engineering, Istanbul, Turkey, pp. 393-396.
  6. Cunning, J., Robertson, P. and Sego, D. (1995), Shear wave velocity to evaluate in situ state of cohesionless soils, Canadian Geotechnical Journal, Vol. 32, No. 5, pp. 848-858. https://doi.org/10.1139/t95-081
  7. Dyvik, R. and Madshus, C. (1985), Laboratory measurements of Gmax using bender elements, Proceedings of the ASCE Convention in Detroit, Michigan, USA, pp. 186-196.
  8. Fernandez, A. L. (2000), Tomographic imaging the state of stress, Ph. D dissertation, Georgia Institute of Technology, Atlanta. pp. 298.
  9. Frost, J. and Park, J. Y. (2003), A critical assessment of the moist tamping technique, ASTM Geotechnical Testing Journal, Vol. 26, No. 1, pp. 57-70.
  10. Juneja, A. and Raghunandan, M. (2010), Effect of sample preparation on strength of sands, Indian Geotechnical Conference, Mumbai, India, pp. 327-330.
  11. Ladd, R. S. (1974), Specimen preparation and liquefaction of sands, Journal of Geotechnical and Geoenvironmental Engineering Division, Vol. 100, No. 10, pp. 118-184.
  12. Ladd, R. S. (1978), Preparing test specimens using undercompaction, ASTM Geotechnical Testing Journal, Vol. 1, No. 1, pp. 16-23. https://doi.org/10.1520/GTJ10364J
  13. Lee, J. S. and Santamarina, J. C. (2005), Bender elements: performance and signal interpretation, Journal of Geotechnical and Geoenvironmental Engineering, Vol. 131, No. 9, pp. 1063-1070. https://doi.org/10.1061/(ASCE)1090-0241(2005)131:9(1063)
  14. Lee, J. S., Yoon, S. M., Park, C. H. and Yoon, H. K. (2013), A study of theoretical methods for estimating void ratio based on the elastic wave velocities, Journal of the Korean Geotechnical Society, Vol. 29, No. 2, pp. 35-45 (in Korean). https://doi.org/10.7843/kgs.2013.29.2.35
  15. Raghunandan, M., Juneja, A. and Hsiung, B. (2012), Preparation of reconstituted sand samples in the laboratory, International Journal of Geotechnical Engineering, Vol. 6, No. 1, pp. 125-131. https://doi.org/10.3328/IJGE.2012.06.01.125-131
  16. Richart, F. E., Hall, J. R. and Woods, R. D. (1970), Vibrations of soils and foundations, Prentice-Hall, Englewood Cliffs, New Jersey. pp. 414.
  17. Robertson, P., Sasitharan, S., Cunning, J. and Sego, D. (1995), Shear-wave velocity to evaluate in-situ state of Ottawa sand, Journal of Geotechnical Engineering, Vol. 121, No. 3, pp. 262-273. https://doi.org/10.1061/(ASCE)0733-9410(1995)121:3(262)
  18. Skempton, A. (1954), The pore-pressure coefficients A and B, Geotechnique, Vol. 4, No. 4, pp. 143-147. https://doi.org/10.1680/geot.1954.4.4.143
  19. Terzaghi, K. and Peck, R. B. (1948), Soil mechanics in engineering practice, J. Wiley, New York. pp. 150.
  20. Vaid, Y. and Negussey, D. (1988), Preparation of reconstituted sand specimens, Advanced triaxial testing of soil and rock, ASTM STP, Vol. 977, pp. 405-417.
  21. Viggiani, G. and Atkinson, J. (1995), Interpretation of bender element tests, International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts, Vol. 32, No. 8, pp. 373A.
  22. Yoon, H. K., Kim, D. H., Lee, W. J. and Lee, J. S. (2010), Field elastic wave and electrical resistivity penetrometer for evaluation of elastic moduli and void ratio, Jounal of the Korean Society of Civil Engineers C, Vol. 30, No. 2C, pp. 85-93 (in Korean).
  23. Yoshimi, Y., Tokimatsu, J. and Ohara, A. (1994), In situ liquefaction resistance of clean sands over a wide density range, Geotechnique, Vol. 44, No. 3, pp. 479-494. https://doi.org/10.1680/geot.1994.44.3.479