Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
권호 표지
DOI QR코드

DOI QR Code

Shear Strength Characteristics of Geo - Soluble - Materials

용해재료가 포함된 지반의 전단강도 특성

  • Tran, M. Khoa (School of Civil, Environmental, and Architectural Engineering, Korea University) ;
  • Park, Jung-Hee (School of Civil, Environmental, and Architectural Engineering, Korea University) ;
  • Byun, Yong-Hoon (School of Civil, Environmental, and Architectural Engineering, Korea University) ;
  • Shin, Ho-Sung (Department of Civil and Environment Engineering, Ulasn University) ;
  • Lee, Jong-Sub (School of Civil, Environmental, and Architectural Engineering, Korea University)
  • 짠밍콰 (고려대학교 건축사회환경공학부) ;
  • 박정희 (고려대학교 건축사회환경공학부) ;
  • 변용훈 (고려대학교 건축사회환경공학부) ;
  • 신호성 (울산대학교 건설환경공학부) ;
  • 이종섭 (고려대학교 건축사회환경공학부)
  • Received : 2011.05.12
  • Accepted : 2011.12.13
  • Published : 2011.12.30
Download PDF
⟨ Previous Next ⟩

Abstract

A fabric of soil media may change due to certain factors such as dissolution of soluble particles, desiccation, and cementation. The fabric changes affect the mechanical behavior of soils. The purpose of this study is to investigate the effects of geo-material dissolution on shear strength. Experiments and numerical simulations are carried out by using a conventional direct shear and the discrete element method. The dissolution specimens are prepared with different volumetric salt fraction in sand soils. The dissolution of the specimens is implemented by saturating the salt-sand mixtures at different confining stresses in the experimental study or reducing the sizes of soluble particles in the numerical simulations. Experimental results show that the angle of shearing resistance decreases with the increase in the soluble particle content and the shearing behavior changes from dilative to contractive behavior. The numerical simulations exhibit that macro-behavior matches well with the experimental results. From the microscopic point of view, the particle dissolution produces a new fabric with the increase of local void, the reduction of contact number, the increase of shear contact forces, and the anisotropy of contact force chains compared with the initial fabric. The shearing behavior of the mixture after the particle dissolution is attributed to the above micro-behavior changes. This study demonstrates that the reduction of shearing resistance of geo-material dissolution should be considered during the design and construction of the foundation and earth-structures.

흙입자의 구조는 흙을 구성하는 용해성 입자의 용해작용, 건조작용 그리고 고결화 현상과 같은 특정요인에 의해 영향을 받으며 입자구조의 변화는 흙의 역학적 거동에 큰 영향을 미친다. 본 논문에서는 흙속에 포함된 용해성입자의 용해작용이 전단강도에 미치는 영향을 조사하였다. 직접전단실험을 위해 소금과 모래로 구성된 혼합재를 이용하여 시료를 조성하고 전체시료에 대한 용해성 입자의 부피비를 조절하면서 실험을 수행하였으며 실험과 동일한 조건하에 서 수치해석을 수행하였다. 입자의 소실과정을 위해 실험에서는 소금-모래 혼합재를 포화시켜 소금을 용해시켰으며 수치해석에서는 용해성 입자의 크기를 줄이는 것으로 용해과정을 모사하였다. 실험결과, 용해성 입자의 부피비가 증가할수록 내부마찰각은 감소하였고, 시료의 수직변형은 팽창거동에서 수축거동으로 변화하였다. 수치해석은 실험 결과와 유사한 거시적 거동을 보여주었다. 미시적관점에서, 입자가 용해됨에 따라 간극비의 증가, 접촉점 수의 감소, 전단접촉력의 증가, 접촉력 연결고리의 이방성에 의해 새로운 입자구조가 생성됨을 보여주었다. 이러한 미시적 거동의 변화는 입자의 용해작용 후 전단거동에 영향을 주게 된다. 본 연구에서는 기초나 지반구조물의 설계와 시공 시 지반재료의 용해에 따른 전단강도을 고려해야 함을 보여준다.

Keywords

References

  1. Azam, S. (2000). "Collapse and compressibility behaviour of arid calcureous soil formations", B. Eng. Geol. Environ, 59(3), 211-217. https://doi.org/10.1007/s100640000060
  2. Bell, F. G. (2007). Engineering Geoloty 2nd edn, Elsevier, Create Britain.
  3. Craft, D. (2005). "Seepage chemistry manual", Report DSO-05-03, US Department of the Interior, Buureau of Reclamation, Dam Safety Technology Development Program, Denver, Colorado.
  4. Cui, L., and O'Sullivan, C. (2006). "Exploring the macro- and micro-scale response of an idealised granular material in the direct shear apparatus", Geotechnique, 56(7), 445-468. https://doi.org/10.1680/geot.2006.56.7.445
  5. Cundall, P. A., and Strack, O. D. L. (1979). "A discrete numerical model for granular assemblies", Geotechnique, 29(1), 47-65. https://doi.org/10.1680/geot.1979.29.1.47
  6. Fam, M. A., Cascante, G., and Dusseault, M. B. (2002). "Large and small strain properties of sands subjected to local void increase", Journal of Geotechnical and Geoenvironmental Engineering, 128(12), 1018-1025. https://doi.org/10.1061/(ASCE)1090-0241(2002)128:12(1018)
  7. Jewell, R. A. (1989). "Direct shear tests on sand", Geotechnique, 39(2), 309-322. https://doi.org/10.1680/geot.1989.39.2.309
  8. Lings, M. L., and Dietz, M. S. (2004). "An improved direct shear appartus for sand", Geotechnique, 54(4), 245-256. https://doi.org/10.1680/geot.2004.54.4.245
  9. Masson, S., and Martinez, J. (2001). "Micromechanical analysis of the shear behavior of a granula material", Journal of Geotechnical and Geoenvironmental Engineering, 127(10), 1007-1016.
  10. Mikheev, V. V., and Petrukhin, V. P. (1973). "Construction properties of saline soils used as foundaation beds in industrial and civil construction", Constrcution under special soil conditions.
  11. O'Suliivan, C. (2002). "The application of discrete element modelling to finite deformation problems in geomechanics", PhD thesis, Department of Civil Engineering, University of California, Berkeley.
  12. O'Suliivan, C., Bray, J. D., and Riemer, M. (2004). "Examination of the Response of the Regularly Packed Specimens of Spherical Particles Using Physical Tests and Discrete Element Simulation", Journal of Geotechnical and Geoenvironmental Engineering, 130(10), 1140-1150. https://doi.org/10.1061/(ASCE)1090-0241(2004)130:11(1140)
  13. PFC2D. User's manual, Itasca Consulting Group, Inc.
  14. Rothenburg, L. (1980). "Micromechanis of idealized granular system", Ph.D. Dissertation, Carleton University, Ottawa, Ontario, Canada.
  15. Rothenburg, L., and Bathurst, R. j. (1989). "Analytical study of induced anisotropy in idealized granular materials", Geotechnique, 39(4), 601-614. https://doi.org/10.1680/geot.1989.39.4.601
  16. Shibuya, S., Mitachi, T., and Tamate, S. (1997). "Interpretation of direct shear box testing of sands as quasi-simple shear", Geotechnique, 47(4), 769-790. https://doi.org/10.1680/geot.1997.47.4.769
  17. Shin, H., and Santamarina, J. C. (2009). "Mineral Dissolution and the Evolution of k0", Journal of Geotechnical and Geoenvironmental Engineering, 135(8), 1141-1147. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000053
  18. Thornton, C. (2000). "Numerical simualtion of deviatoric shear deformation of granualr media", Geotechnique, 50(1), 43-53. https://doi.org/10.1680/geot.2000.50.1.43
  19. Ting, J. M., Corkum, B. T., Kauffman, C. R., and Greco, C. (1989). "Discrete numerical model for soil mechanics", Journal of Geotechnical and Geoenvironmental Engineering, 115(3), 379-398. https://doi.org/10.1061/(ASCE)0733-9410(1989)115:3(379)
  20. Truong, Q. H., Eom, Y. H., and Lee, J. S. (2010). "Stiffness characteristics of soluble mixtures", Geotechnique, 60(4), 293-297. https://doi.org/10.1680/geot.8.T.032
  21. Wang, J., Dove, J. E., and Gutierrez, M. S. (2007). "Discretecontinuum analysis of shear banding in the direct shear test", Geotechnique, 57(6), 513-526. https://doi.org/10.1680/geot.2007.57.6.513
  22. Zhang, L., and Thornton, C. (2007). "A numerical examination of the direct shear test", Geotechnique, 57(4), 343-354. https://doi.org/10.1680/geot.2007.57.4.343

Cited by

  1. 탄성파를 이용한 모래-실트 혼합토의 동결-융해 특성 vol.15, pp.5, 2011, https://doi.org/10.14481/jkges.2014.15.5.47