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Establishing an opening size criterion in direct shear test using DEM Simulation

  • Kim, Byeong-Su (Graduate School of Environmental and Life Science, Okayama University)
  • 투고 : 2021.02.15
  • 심사 : 2021.06.29
  • 발행 : 2021.07.25

초록

Direct shear test has been widely used to examine the shear strength of geomaterials because of the simplicity of the testing method and apparatus. Three factors significantly affect the accuracy of the experimental results of direct shear tests, namely (1) the type of direct shear apparatus, (2) the specimen size (scale effect), and (3) the opening size between shear boxes. This study focused on the Threshold Line (TL), which is obtained based on experimental tests, as a guideline for setting the opening size between the shear boxes. The validity of the TL was examined using distinct element method (DEM) 3D simulations from the following four perspectives: the first and second perspectives investigated the influence of the mean particle size and particle size distribution for mean particle sizes larger than 0.8 mm. In the third perspective, the scale effect of the specimens for fixed and varying D:H ratios of the shear box to reduce the shear box size was examined. Lastly, in the fourth perspective, the validity of using the TL to determine the appropriate opening size for the samples with a mean particle size smaller than 0.8 mm was also examined based on the Threshold Point (TP). For each case, the results of the TPs obtained from the DEM simulations agreed well with those of the TL. These findings suggest that the TL is valid and the TL relational equation can be used for setting the opening size between the shear boxes in the direct shear test regardless of saturated and unsaturated soils.

키워드

참고문헌

  1. ASTM International (2009), Annual Book of Standards. Vol. 04.08, Soil and Rock, ASTM International, West Conshohocken, Pennsylvania, U.S.A.
  2. Bian, X., Li, W., Qian, Y. and Tutumluer, E. (2019), "Micromechanical particle interactions in railway ballast through DEM simulations of direct shear tests", Int. J. Geomech., 19(5), 04019031. https://doi.org/10.1061/(ASCE)GM.1943-5622.0001403.
  3. Cerato, A.B. and Lutenegger, A.J. (2006), "Specimen size and scale effects of direct shear box tests of sands", Geotech. Test. J., 29(6), 1-10. https://doi.org/10.1520/GTJ100312.
  4. Cho, S.E. (2008), "Infiltration analysis to evaluate the surficial stability of two-layered slopes considering rainfall characteristics", Eng. Geol., 105(1), 32-43. https://doi.org/10.1016/j.enggeo.2008.12.007.
  5. Cundall, P.A. (1971), "A computer model for simulating progressive, large-scale movement in blocky rock system", Proceedings of the International Symposium on Rock Mechanics, Nancy, France,
  6. 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.
  7. Gan, J.K.M., Fredlund, D.G. and Rahardjo, H. (1988), "Determination of the shear strength parameters of an unsaturated soil using the direct shear test", Can. Geotech. J., 25(8), 500-510. https://doi.org/10.1139/t88-055.
  8. Guo, P. (2008), "Modified direct shear test for anisotropic strength of sand", J. Geotech. Geoenviron. Eng., 134(9), 1311-1318. https://doi.org/10.1061/(ASCE)1090-0241(2008)134:9(1311).
  9. Hight, D.W. and Leroueil, S. (2003), "Characterisation of soils of engineering purposes", Proceedings of the International Workshop, Singapore, December.
  10. Itasca Consulting Group Inc. (2005), PFC-3D User's Guide Version 3.1, Itasca Consulting Group, Minnesota, U.S.A.
  11. Jewell, R.A. and Wroth, C.P. (1987), "Direct shear test on reinforced sand", Geotechnique, 37(1), 53-68. https://doi.org/10.1680/geot.1987.37.1.53.
  12. Kim, B.S., Shibuya, S., Park, S.W. and Kato, S. (2010), "Application of suction stress for estimating unsaturated shear strength of soils using direct shear testing under low confining pressure", Can. Geotech. J., 47(9), 955-970. https://doi.org/10.1139/T10-007.
  13. Kim B.S., Shibuya S., Park S.W. and Kato, S. (2012), "Effect of opening on shear behavior of granular material in direct shear test", KSCE J. Civ. Eng., 16(7), 1132-1142. https://doi.org/10.1007/s12205-012-1518-4.
  14. Kim, B.S., Shibuya, S., Park, S.W. and Kato, S. (2013), "Suction stress and its application on unsaturated direct shear test under constant volume condition", Eng. Geol., 155, 10-18. https://doi.org/10.1016/j.enggeo.2012.12.020.
  15. Kim, B.S., Park, S.W. and Kato, S. (2014), "DEM simulation on deformation mode and stress state for specimen shape in direct shear test", Int. J. Comput. Meth., 11(2), 1342004. https://doi.org/10.1142/S0219876213420048.
  16. Kodicherla, S.P.K., Gong, G., Yang, Z.X., Krabbenhoft, K., Fan, L., Moy, C.K. and Wilkinson, S. (2019), "The influence of particle elongations on direct shear behaviour of granular materials using DEM", Granul. Matter, 21(4), 1-12. https://doi.org/10.1007/s10035-019-0947-x.
  17. Lee, S., Chang, I., Chung, M.K., Kim, Y. and Kee, J. (2017), "Geotechnical shear behavior of xanthan gum biopolymer treated sand from direct shear testing", Geomech. Eng., 12(5), 831-847. https://doi.org/10.12989/gae.2017.12.5.831.
  18. Lin, H.D., Wang, C.C. and Wang, X.H. (2018), "A simplified method to estimate the total cohesion of unsaturated soil using an UC test", Geomech. Eng., 16(6), 599-608. https://doi.org/10.12989/gae.2018.16.6.599.
  19. Liu, S.H. (2006), "Simulating a direct shear box test by DEM", Can. Geotech. J., 43(2), 155-168. https://doi.org/10.1139/t05-097.
  20. Ng, C.W.W.,and Shi, Q. (1998), "A numerical investigation of the stability of unsaturated soil slopes subjected to transient seepage", Comput. Geotech., 22(1), 1-28. https://doi.org/10.1016/S0266-352X(97)00036-0.
  21. Ni, Q., Powrie, W., Zhang, X. and Harkness, R. (2000), "Effect of particle properties on soil behavior: 3-D numerical modeling of shearbox tests", In Numer. Methods in Geotech. Eng. (eds G.M. Filz and D.V. Griffiths), ASCE Geotechnical Special Publication (96), 58-70. https://doi.org/10.1061/40502(284)5.
  22. Meguid, M.A. and Khan, M.I. (2019). "On the role of geofoam density on the interface shear behavior of composite geosystems", Int. J. Geo-Eng., 10(1), 1-18. https://doi.org/10.1186/s40703-019-0103-9.
  23. Oda, M. and Iwashita, K. (2000), "Study on couple stress and shear band development in granular media based on numerical simulation analyses", Int. J. Eng. Sci., 38(15), 1713-1740. https://doi.org/10.1016/S0020-7225(99)00132-9.
  24. Oh, W.T. and Vanapalli, S. (2018), "Undrained shear strength of unsaturated soils under zero or low confining pressures in the vadose zone", Vadose Zone J., 17, 180024. https://doi.org/10.2136/vzj2018.01.0024.
  25. Palmeira, E.M. and Milligan, G.W.E. (1989), "Scale effects in direct shear tests on sand", Proceedings of 12th International Conference on Soil Mechanics and Foundation Engineering, Rio de Janeiro, Brasil.
  26. Parsons, J.D. (1936), "Progress report on an investigation of the shearing resistance of cohesionless soils", Proceedings of 1st International Conference on Soil Mechanics and Foundation Engineering, Cambridge, Massachusetts, U.S.A.
  27. Scarpelli, G. and Wood, D.M. (1982), "Experimental observations of shear band patterns in direct shear", Proceedings of the IUTAM Conference on Deformation and Failure of Granular Materials, Delft, The Netherlands, 472-484.
  28. 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.
  29. Stone, K.J.L. and Muir Wood, D. (1992), "Effects of dilatancy and particle size observed in model tests on sand", Soils Found., 32(4), 43-57. https://doi.org/10.3208/sandf1972.32.4_43.
  30. Suhr, B., Marschnig, S. and Six, K. (2018), "Comparison of two different types of railway ballast in compression and direct shear tests: experimental results and DEM model validation", Granular Matter, 20(4), 1-13. https://doi.org/10.1007/s10035-018-0843-9.
  31. Sweta, K., and Hussaini, S.K.K. (2018), "Effect of shearing rate on the behavior of geogrid-reinforced railroad ballast under direct shear conditions", Geotext. Geomembranes, 46(3), 251-256. https://doi.org/10.1016/j.geotexmem.2017.12.001.
  32. Tatsuoka, F., Nakaumura, S., Huang, C.C. and Tani, K. (1990), "Strength anisotropy and shear band direction in plane strain tests in sand", Soils Found., 30(1), 35-54. https://doi.org/10.3208/sandf1972.30.35.
  33. Thornton, C. (2000), "Numerical simulations of deviatoric shear deformation of granular media", Geotechnique, 50(1), 43-53. https://doi.org/10.1680/geot.2000.50.1.43.
  34. Vanapalli, S.K., Fredlund, D.G., Pufahl, M.D. and Clifton, A.W. (1996), "Model for prediction of shear strength with respect to soil suction", Can. Geotech. J., 33(3), 379-392. https://doi.org/10.1139/t96-060.
  35. Wang, G. and Sassa, K. (2003), "Pore-pressure generation and movement of rainfall-induced landslides: Effects of grain size and fine-particle content", Eng. Geol., 69(1-2), 109-125. https://doi.org/10.1016/S0013-7952(02)00268-5.
  36. Xu, W.J., Li, C.Q. and Zhang, H.Y. (2015), "DEM analyses of the mechanical behavior of soil and soil-rock mixture via the 3D direct shear test", Geomech. Eng., 9(6), 815-827. http://doi.org/10.12989/gae.2015.9.6.815.
  37. Yan, W.M. (2009), "Fabric evolution in a numerical direct shear test," Comput. Geotech., 36(4), 597-603. https://doi.org/10.1016/j.compgeo.2008.09.007.
  38. Yatabe, R., Oshima, A. and Suzuki, K. (1995), "Results of round robin test on direct shear test", Proceedings of International Symposium on Direct Shear Box Testing of Soils, Paris, France, September.
  39. Zhang, L. and Thornton, C. (2007), "A numerical examination of the direct shear test", Geotechnique, 57(5), 343-354. https://doi.org/10.1680/geot.2007.57.4.343.