한국지반공학회논문집 (Journal of the Korean Geotechnical Society)

한국지반공학회 (Korean Geotechnical Society)
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PFC를 이용한 입자 형상에 따른 입자 파쇄 및 전단거동 전개

Evolution of Particle Crushing and Shear Behavior with Respect to Particle Shape Using PFC

  • 조선아 (건국대학교 사회환경시스템공학과) ;
  • 조계춘 (한국과학기술원 건설 및 환경공학과) ;
  • 이석원 (건국대학교 사회환경시스템공학과)
  • 투고 : 2009.02.24
  • 심사 : 2009.10.09
  • 발행 : 2009.10.31
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초록

조립재료의 입자 형상이 입자 파쇄 전개 및 전단 거동 특성에 미치는 영향을 분석하기 위하여, 개별요소법(DEM, discrete element method)을 이용하여 직접전단시험을 수치해석적으로 모델링하였다. PFC(Particle Flow Code)내의 clump 모델 및 cluster 모델을 이용하여 6가지 형상의 입자를 생성하여 이를 원형입자의 직접 전단거동과 비교 분석함으로써 입자형상의 영향을 연구하였다. 연구결과, PFC에 의해 모델링된 직접 전단모델의 수치해석 결과는 실내 실험결과와 잘 일치하였으며, 따라서 본 연구 결과의 타당성을 입증하였다. 입자 형상 관점에서 모나고 거친 입자의 내부마찰각이 상대적으로 둥글고 매끄러운 입자에 비해 큰 값을 나타냈으며, 입자 파쇄 또한 많이 발생하는 것을 확인하였다. 이때 입자파쇄는 전단면근처에 집중되며 전단대를 형성하였다. 따라서 본 연구에서 제시한 수치해석 모델은 향후입자 파쇄를 포함한 조립재료의 전단강도 특성 연구에 다양하게 적용될 수 있다고 판단된다.

In order to analyze the influence of particle shape on evolution of particle crushing and characteristic of shear behavior of granular soil, direct shear test was simulated by using DEM (Discrete Element Method). Six particle shapes were generated by clump and cluster model built in PFC (Particle Flow Code). The results of direct shear test for six particle shapes were compared and analyzed with those for circular particle shape. The results of numerical tests showed a good agreement with those of experimental tests, thus the appropriateness of numerical modelling set in this study was proved. As for particle shape, more angular and rougher particle induced larger internal friction angle and more particle crushing than relatively round and smooth particle. When particles were crushed, crushing was concentrated on the shear band adjacent to the shear plane. Finally, it can be concluded that the numerical models suggested in this study can be used extensively for other studies concerning the shear behavior of granular soil including soil crushing.

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참고문헌

  1. 조남각, 유충식, 이대영 (2008), "개별요소법을 이용한 쇄석재료 의 직접전단시험 모델링", 한국지반공학회논문집, Vol.24, No.1, pp.15-23
  2. Barret, P. J. (1980), "The shape of rock particles, a critical review", Sedimentology, Vol.27, pp.291-303 https://doi.org/10.1111/j.1365-3091.1980.tb01179.x
  3. Bolton, M. D. (1986), "The strength and dilatancy of sands", Geotechnique, Vol.36, No.1, pp.65-78 https://doi.org/10.1680/geot.1986.36.1.65
  4. Cheng, Y. P., Nakata, Y. and Bolton, M. D. (2003), "Discrete element simulation of crushable soil', Geotechnique, 53(7), pp.633-641 https://doi.org/10.1680/geot.2003.53.7.633
  5. Cundall, P. A. and Strack, O. D. L. (1979), "A discrete numerical model for granular assemblies", Geotechnique, Vol.29, No.1, pp.47-65 https://doi.org/10.1680/geot.1979.29.1.47
  6. Feda, J. (2002), "Notes on the effect of grain crushing on the granular soil behavior", Engineering Geology, Vol.63, pp.93-98 https://doi.org/10.1016/S0013-7952(01)00072-2
  7. Hagerty, M. M., Hite, D. R., Ulrich, C. R. and Hagerty, D. J. (1993), "One dimensional high pressure compression of granular media", J. Geotech. Eng., Vol.119, No.1, pp.1-18 https://doi.org/10.1061/(ASCE)0733-9410(1993)119:1(1)
  8. Hainbuchner, E., Ptthoff, S., Konietzky, H. and te Kamp, L. (2003), "Particle based modeling of shear box tests and stability problems for shallow foundations in sand", Numerical Modeling in Micromechanics via Particle Methods, Lisse, pp.151-156
  9. Itasca Consulting Group, Inc. (2004), "Particle Flow Code in 2dimensions, Ver. 3.10, User’s manual", Minneapolis, Itasca
  10. Jensen, R. P., Bosscher, P.J., Plesha, M. E. and Edil, T.B. (1999), "DEM simulation of granular media-structure interface: effects of surface roughness and particle shape", International Journal for Numerical and Analytical Methods in Geomechnics, Vol.23, pp. 531-547 https://doi.org/10.1002/(SICI)1096-9853(199905)23:6<531::AID-NAG980>3.0.CO;2-V
  11. Jensen, R. P., Plesha, M. E., Edil, T. B., Bosscher, P. J. and Kahla, N. B. (2001), "DEM simulation of particle damage in granular media—structure interfaces", Int. J. Geomech., 1(1), pp.21–40 https://doi.org/10.1080/15323640108500148
  12. Krumbein, W. C. (1941), "Measurement and geological significance of shape and roundness of sedimentary particle", J. Sediment. Petrol., Vol.11, No.2, pp.64-72 https://doi.org/10.1306/D42690F3-2B26-11D7-8648000102C1865D
  13. Kumbein, W. C. and Sloss, L. L. (1963), Stratigraphy and sedimentation, 2nd Ed., Freeman and Company, San Francisco
  14. Lade, P. V., Yamamuro, J. A. and Bopp, P. A. (1996), "Significance of particle crushing in granular materials", J. Geotech. Eng., Vol.122, No.4, pp.309-316 https://doi.org/10.1061/(ASCE)0733-9410(1996)122:4(309)
  15. Lee, K. L. fand Farhoomand, I. (1967), "Compressibility and crushing of granular soil in anisotropic triaxial compression', Can. Geotech. J., Vol.4, No.1, pp.68-86 https://doi.org/10.1139/t67-012
  16. Liu, S. H. (2006), "Simulating a direct shear box test by DEM", Canadian Geotechnical Journal, Vol.43, pp.155-168 https://doi.org/10.1139/t05-097
  17. Lobo-Guerrero, S. and Vallejo, L. E. (2005), "Discrete element method evaluation of granular crushing under direct shear test conditions", J. Geotech. and Geoenvir. Eng., Vol.131, pp.1295-1300 https://doi.org/10.1061/(ASCE)1090-0241(2005)131:10(1295)
  18. Masson, S. and Martinez, J. (2001), "Micromechanical analysis of the shear behaviour of a granular material", ASCE J. Eng. Mech., Vol.127, No.10, pp.1007-1016 https://doi.org/10.1061/(ASCE)0733-9399(2001)127:10(1007)
  19. Matsushima, T., Saomoto, H., Matsumoto, M., Toda, K. and Yamada, Y. (2003), "Discrete element simulaton of an assembly of irregularly-shaped grains: Quantitative comparison with experiments'" 16th ASCE Eng. Mech. Conference, Univ. of Washington, Seattle, 16-18 July 2003
  20. McDowell, G. R. and Harireche, O. (2002), "Discrete element modelling of yielding and normal compression of sand", Geotechnique, 52(4), pp.299-304 https://doi.org/10.1680/geot.2002.52.4.299
  21. O’Sullivan, C., Cui, L. and Bray, J. D. (2004), "Three-dimensional discrete element simulations of direct shear tests", Numerical Modeling in Micromechanics via Particle Methods, London, pp. 373-382
  22. Power, M. C. (1953), "A new roundness scale for sedimentary particles", J. Sediment. Petrol., Vol.23, No.2, pp.117-119
  23. Wadell, H. (1932), "Volume, Shape, and roundness of rock particle", J. Geol., Vol.40, No.3, pp.443-451 https://doi.org/10.1086/623964
  24. Zhang, L. and Thornton, C. (2007), "A numerical examination of the direct shear test', GTEX>$\'{e}$otechnique, Vol.57, No.4, pp.343-354