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

  • 제13권4호
  • /
  • Pages.45-51
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  • 2012
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  • 1598-0820(pISSN)
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  • 2714-1233(eISSN)
한국지반환경공학회 (Korean Geo-Environmental Society)
권호 표지

모관흡수력에 따른 화강풍화토의 유효응력과 전단강도의 관계

The Relationship Between Effective Stress and Shear Strength of Weathered Granite Soils Based on Matric Suctions

  • 이영휘 (영남대학교 건설시스템공학과) ;
  • 오세붕 (영남대학교 건설시스템공학과) ;
  • 김광현 ((주)에스코컨설턴트) ;
  • 성열호 (대림산업(주) 기술개발원 토목연구지원팀)
  • 발행 : 2012.04.01
⟨ 이전 논문 다음 논문 ⟩

초록

불포화토를 대상으로 $K_0$ 압밀조건에서 삼축시험을 수행하여 전단강도를 분석하였다. 불포화 삼축압축시험에서는 대구지역에 있는 풍화토 시료를 성형하여 다양한 모관흡수력을 조절하였다. 건조 및 습윤 시 함수특성시험을 수행하여 실험치들을 van Genuchten 곡선으로 모델하였다. 함수특성곡선으로부터 모관흡수력이 유효응력에 기여하는 성분을 평가할 수 있다. 이로부터 유효응력을 산정하였으며 유효응력에 따른 전단강도를 결정하였다. 다양한 모관흡수력에 따른 전단강도는 유효응력으로 기술하였을 때, 유일한 직선으로 나타나며 포화토의 파괴포락선과 일치함을 알 수 있었다.

The shear strength of weathered granite soils under unsaturated condition was evaluated by $K_0$ consolidated triaxial tests. Various matric suctions in the unsaturated triaxial tests were applied using suction-controlled triaxial test apparatus for weathered granite soils obtained in Daegu. Soil water characteristic curve (SWCC) laboratory tests for drying and wetting procedure were performed and van Genuchten curves were fitted by experimental results. The contribution of matric suction in unsaturated soils is directly correlated to effective stress and evaluated from SWCCs. The effective stresses were estimated from these SWCCs and the relationship between effective stress and unsaturated shear strength was determined. In the effective stress description, the unsaturated shear strength with respect to various suctions indicates unique relationship and almost the same as that of the saturated envelope.

키워드

참고문헌

  1. Bishop, A. W. (1954), The Use of Pore Water Coefficients in Practice, Geotechnique, Vol. 4, No. 4, pp. 148-152. https://doi.org/10.1680/geot.1954.4.4.148
  2. Bishop, A. W. (1959), The Principle of Effective Stress, Teknisk Ukeblad I Samarbeide MedTeknikk, Oslo, Norway, Vol. 106, No. 39, pp. 859-863.
  3. Bishop, A. W., and Blight, G. E. (1963), Some Aspects of Effective Stress in Saturated and Partly Saturated Soils, Geotechnique, Vol. 13, No. 3, pp. 177-197. https://doi.org/10.1680/geot.1963.13.3.177
  4. Fredlund, D. G., Mogenstern, N. R.(1977), Stress State Variablea for Unsatured Soils, Journal of Geotechnicaland Geoenvironmental Engineering, Vol. 103, No. 5, pp. 447-466.
  5. Kim, T. H. (2009), The Influence of Overburden Pressure and Volume Change on the Soil-water Characteristic Curve of Unsaturated Weathered Granite Soil, MSc Thesis, Yeungnam Univ. pp. 68-75.(in Korean)
  6. Kim, T.-K. (2011), On the Effective Stress of Unsaturated Soils During K0 Consolidated Triaxial Tests, Ph.D. Thesis, Yeungnam Univ. pp. 89-95.(in Korean)
  7. Kim, T. K. and Oh, S (2008), On the Bishop Stress of Unsaturated Soils under the Low Level of Matric Suction, Journal of Korean Geotechnical Society, Vol. 24, No. 7, pp. 17-24.(in Korean)
  8. Lee, S. J., Lee, S. R. and Jang, B. S. (2002), Unsaturated Shear Strength Characteristics of Weathered Granite Soils, Journal of Korea Society of Civil Engineers, Vol. 22, No. 1C, pp. 81-88.(in Korean)
  9. Lu, N., and Likos, W. J. (2006), Suction Stress Characteristic Curve for Unsaturated Soils, Journal of Geotechnicaland Geoenvironmental Engineering, Vol. 132, No. 2, pp. 131-142. https://doi.org/10.1061/(ASCE)1090-0241(2006)132:2(131)
  10. Lu, N., and Godt, J., and Wu, D. T. (2010), A Closed-form Equation for Effective Stress in Unsaturated Soil, Water Resources Research, Vol. 46, W05515. pp. 1-14.
  11. Oh, S, Mun, J.-H., Kim, T.-K., Kim, Y. K. (2008), A Case Study of Rainfall-Induced Slope Failures on the Effect of Unsaturated Soil Characteristics, Journal of Korea Society of Civil Engineers, Vol. 28, No. 3C, pp. 167-178.(in Korean)
  12. Vanapalli, S.K., Fredlund, D.G., Pufahl, D,E. and Clifton, A,W.(1996), Model for the Prediction of Shear Strength with Respect to Soil Suction, Canadian Geotechnical Journal, Vol. 33, No. 3, pp. 379-392. https://doi.org/10.1139/t96-060
  13. van Genuchten, M. T. (1980), A Closed-form Equation for Predicting the Hydraulic Conductivity of Unsaturated Soils, Soil Science Society of America Journal, Vol. 44, No. 5, pp. 892-898. https://doi.org/10.2136/sssaj1980.03615995004400050002x
  14. van Genuchten, M. T., Leij, F. J., and Yates, S. R. (1991), The RETC Code for Quantifying the Hydraulic Functions of Unsaturated Soils, EPA600/2-91/065. pp. 4-12.