한국지반공학회논문집 (Journal of the Korean Geotechnical Society)

  • 제28권8호
  • /
  • Pages.21-29
  • /
  • 2012
  • /
  • 1229-2427(pISSN)
  • /
  • 2288-646X(eISSN)
한국지반공학회 (Korean Geotechnical Society)
권호 표지
DOI QR코드

DOI QR Code

입자의 조건에 따른 정지토압계수 평가

Evaluation of at Rest Lateral Stress Coefficient Influenced by Particle Condition

  • 이정훈 (연세대학교 사회환경시스템공학부 토목공학과) ;
  • 이동열 (연세대학교 사회환경시스템공학부 토목공학과) ;
  • 윤태섭 (연세대학교 사회환경시스템공학부 토목공학과) ;
  • 이준환 (연세대학교 사회환경시스템공학부 토목공학과)
  • Lee, Jung-Hwoon (Dept. of Civil and Environmental Engineering, Yonsei Univ.) ;
  • Lee, Dong-Ryeol (Dept. of Civil and Environmental Engineering, Yonsei Univ.) ;
  • Yun, Tae-Sup (Dept. of Civil and Environmental Engineering, Yonsei Univ.) ;
  • Lee, Jun-Hwan (Dept. of Civil and Environmental Engineering, Yonsei Univ.)
  • 투고 : 2012.01.18
  • 심사 : 2012.08.03
  • 발행 : 2012.08.31
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

기초 구조물, 옹벽 등 지반 구조물의 거동 평가에 사용되는 정지토압계수는 현장 응력상태를 나타내는 상태변수로 해석과 설계에 매우 중요하다. 정규 압밀된 사질토에서 일반적으로 널리 쓰이는 Jaky의 Ko식은 실험에서 획득 가능한 마찰각으로부터 응력상태를 유추하지만, 실무에서 마찰각 적용시 필수적인 입자 조건에 따른 영향과 기준에 대한 평가가 어렵다. 따라서 본 연구에서는 주요한 영향 인자로서 상대밀도, 원마도, 표면 거칠기에 따른 Ko값의 변화 양상을 다양한 하중 단계별로 실험에 고려하였다. 변형계를 사용한 Ko측정기를 제작하여 주문진 표준사, 글라스 비드, 에칭 글라스 비드에 대해 재하-제하-재재하의 단계별로 Ko을 측정하였고 영향 요인별 분석을 실시하였다. 실험 결과 원마도와 무관하게 작은 상대밀도의 시편이 높은 Ko을 보였으며 표면 거칠기는 Ko에 큰 영향이 없었다. 또한 동일한 상대밀도에서 입자가 모난 형상에 가까울수록 낮은 Ko을 보였다. 본 연구에서 획득한 실험 결과를 바탕으로 경험식과 문헌에서 보고된 데이터를 이용하여 상대밀도에 따른 Ko과 마찰각의 특성을 분석하였다.

At-rest lateral stress coefficient that is used for the evaluation of geotechnical structures such as foundations and retaining walls plays a significant role in the analysis and design, as a state variable of in-situ stress condition. In the widely applied Jaky's Ko equation stress condition can be inferred from the internal friction angle obtainable from the laboratory experimentation whereas the eguation mares it challenging to evaluate the influences and criteria of particle characteristics which is essential for the application of friction angles in practices. Thus, this study experimentally explored the behaviors of Ko depending on the relative density, particle shape, and surface roughness effect during a range of loading stages. The Ko values of Jumumjin sand, glass beads, and etched glass beads were measured using a customized Ko device housing strain gauges during loading-unloading-reloading steps, and the effect of dominant factors on Ko is analyzed. Results show that the high Ko prevails for both round and angular specimens with low relative density and the surface roughness has a nominal effect. The angular particles exhibit low Ko for specimens with similar relative density. The characteristics of relevance between Ko and friction angles with varying relative density are also investigated based on the experimental results using empirical correlations and previously reported values.

키워드

참고문헌

  1. Andrawes, K. Z. and El-Sohby, M. A. (1973), "Factros affecting coefficient of earth pressure Ko", American Society of Civil Engineers, Journal of the Soil Mechanics and Foundations Division, 99(SM7), pp.527-539.
  2. Choi, C. H. and Ko, S. G. (2011), "A Study for predicting adfreeze bond strength from shear stresng of frozen soil", Journal of Korean Geotechnical Society, Vol.27, No.10, pp.13-23.
  3. Edil, T. B. and Dhowian, A. W. (1981), "At-rest lateral pressure of peat soils", Journal of the Geotechnical Engineering Division, Vol.107, No.2, pp.201-217.
  4. Hong, W. P., Song, J. S. and Hong, S. (2010), "Punching shear failure in pile-supported embankments", Journal of Korean Geotechnical Society, Vol.26, No.3, pp.35-45.
  5. Im, J. C., Lee, T. H. and An, M. H. (2000), "A study on the estimation of internal friction angle of sand ground through the bearing capacity experiments", KSCE Journal of Civil Engineering, Vol.20, No.11, pp.495-506.
  6. Jang, E. R., Choo, Y. S., Lee, W. T. and Chung, C. K. (2008), "Restrained effect of end plate on plane strain test evaluated by digital image correlation method", Journal of Korean Geotechnical Society, Vol.24, No.7, pp.25-36.
  7. Kolymbas, D. and Bauer, E. (1993), "Soft oedometer. A new testing device and its application for the calibration of hypoplastic constitutive laws", Geotechnical Testing Journal, Vol.16, No.2, pp.263-270. https://doi.org/10.1520/GTJ10044J
  8. Lohnes, R. A. (1993), "Lateral stress ratios for particulate materials", Powder Handling & Processing, Vol.5, No.4, pp.331-336.
  9. Mayne, P. W. and Kulhawy, F. H. (1982), "Ko-OCR relationship in soil", Journal of the Geotechnical Engineering Division, 108 (GT6), pp.851-872.
  10. Mesri, G. and Hayat, T. M. (1993), "Coefficient of earth pressure at rest", Canadian geotechnical journal, Vol.30, No.4, pp.647-666. https://doi.org/10.1139/t93-056
  11. Mesri, G. and Vardhanabhuti, B. (2007), "Coefficient of earth pressure at rest for sands subjected to vibration", Canadian geotechnical journal, Vol.44, No.10, pp.1242-1263. https://doi.org/10.1139/T07-032
  12. Michalowski, R. L. (2005), "Coefficient of earth pressure at rest", Journal of Geotechnical and Geoenvironmental Engineering-ASCE, Vol.131, No.11, pp.1429-1433. https://doi.org/10.1061/(ASCE)1090-0241(2005)131:11(1429)
  13. Okochi, Y. and Tatsuoka, F. (1984), "Some factors affecting Kovalues of sand measured in triaxial cell", Soils and Foundations, Vol.24, No.3, pp.52-68. https://doi.org/10.3208/sandf1972.24.3_52
  14. Paik, K. H. and Lee, J. H. (2008), "Calculation of bearing capacity of tapered drilled shafts in cohesionless soils using shape factor", Journal of Korean Geotechnical Socirty, Vol.24, No.12, pp.13-22.
  15. Shin, H. and Santamarina, J. C. (2009), "Mineral dissolution and the evolution of Ko", Journal of Geotechnical and Geoenvironmental Engineering, Vol.135, No.8, pp.1141-1147. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000053
  16. Ting, C. M. R., Sills, G. C. and Wijeyesekera, D. C. (1994), "Development of KO in soft soils", Geotechnique, Vol.44, No.1, pp.101-109. https://doi.org/10.1680/geot.1994.44.1.101
  17. Wang, Y. H. and Leung, S. C. (2008), "Characterization of cemented sand by experimental and numerical investigations", Journal of Geotechnical and Geoenvironmental Engineering, Vol.134, No.7, pp.992-1004. https://doi.org/10.1061/(ASCE)1090-0241(2008)134:7(992)
  18. Yun, T. S. and Evans, T. M. (2011), "Evolution of at-rest lateral stress for cemented sands: experimental and numerical investigation", Granular Matter, Vol.13, pp.671-683. https://doi.org/10.1007/s10035-011-0279-y
  19. Zhu, F. and Clark, J. I. (1994), "Effect of dynamic loading on lateral stress in sand", Canadian geotechnical journal, Vol.31, No.2, pp.308-311. https://doi.org/10.1139/t94-036
  20. Zhu, F., Clark, J. I. and Paulin, M. J. (1995), "Factors affecting at-rest lateral stress in artificially cemented sands", Canadian geotechnical journal, Vol.32, No.2, pp.195-203. https://doi.org/10.1139/t95-023

피인용 문헌

  1. 낮은 구속응력에 대한 주문진 표준사의 강도 및 변형 특성 vol.30, pp.2, 2012, https://doi.org/10.7843/kgs.2014.30.2.33