Geomechanics and Engineering

Techno-Press (테크노프레스)
권호 표지
DOI QR코드

DOI QR Code

DEM study on effects of fabric and aspect ratio on small strain stiffness of granular soils

  • Gong, Jian (College of Civil Engineering and Architecture, Guangxi University) ;
  • Li, Liang (School of Civil Engineering, Central South University) ;
  • Zhao, Lianheng (School of Civil Engineering, Central South University) ;
  • Zou, Jinfeng (School of Civil Engineering, Central South University) ;
  • Nie, Zhihong (School of Civil Engineering, Central South University)
  • Received : 2019.09.11
  • Accepted : 2020.12.24
  • Published : 2021.01.10
⟨ Previous Next ⟩

Abstract

The effects of initial soil fabric and aspect ratio (AR) on the small-strain stiffness (G0) of granular soils are studied by employing discrete element method (DEM) numerical analysis. Elongated clumps composed of subspheres were adopted, and the G0 values were obtained by DEM simulations of drained triaxial tests under different densities and initial confining pressure (p0). The DEM simulations indicate that the initial soil fabric has an insignificant effect on G0. The effect of the AR on G0 is related to the initial density. Namely, for dense specimens, G0 first increases with increasing AR, reaching a plateau value when the AR ≥ 1.5. However, for loose specimens, G0 gradually increases as the AR increases. Microscopic examination reveals that G0 uniquely depends on the coordination number of the particles (CN-particle) rather than the subspheres (CN-sphere) at the particulate level for the effects of initial soil fabric and AR. Finally, Poisson's ratio ν0 is also determined by CN-particle. In addition, based on data in literature and this study, ν0 can be fitted as ν0 = 5.920(G0/(p0)1/3)-0.99, which can be used to predict ν0 of granular soils based on the measured G0.

Keywords

Acknowledgement

This research is supported by the National Natural Science Foundation of China (No. 51809292, 51478481 and 51878668), Postdoctoral Fund of Central South University (No. 205455) and Beijing Municipal Science and Technology Project: Research and Application of Design and Construction Technology of Railway Engineering Traveling the Rift Valley (No. Z181100003918005). The authors would like to express their appreciation to the financial assistance.

References

  1. Altuhafi, F.N., Coop, M.R. and Georgiannou, V.N. (2016), "Effect of particle shape on the mechanical behavior of natural sands", J. Geotech. Geoenviron. Eng., 142(12), 04016071. http://doi.org/10.1061/(ASCE)GT.1943-5606.0001569.
  2. Cho, G.C., Dodds, J. and Santamarina, J.C. (2006), "Particle shape effects on packing density, stiffness, and strength: Natural and crushed sands", J. Geotech. Geoenviron. Eng., 132(5), 591-602. http://doi.org/ 10.1061/(ASCE)1090-0241(2006)132:5(591).
  3. Chuang, R.M., Yokel, F.Y. and Drnevich, V.P. (1984), "Evaluation of dynamic properties of sands by resonant column testing", Geotech Test J, 2(7), 60-69. http://doi.org/10.1520/GTJ10594J.
  4. Cundall, P.A. and Strack, O.D.L. (1979), "A discrete numerical model for granular assemblies", Geotechnique, 29(1), 47-65. http://doi.org/10.1680/geot.1980.30.3.331.
  5. Delaney, G.W. and Cleary, P.W. (2010), "The packing properties of superellipsoids", Europhys. Lett., 89(3), 340023. https://doi.org/10.1209/0295-5075/89/34002.
  6. Donev, A., Cisse, I., Sachs, D., Variano, E., Stillinger, F.H., Connelly, R., Torquato, S. and Chaikin, P.M. (2004), "Improving the density of jammed disordered packings using ellipsoids", Science, 303(5660), 990-993. http://doi.org/10.1126/science.1093010.
  7. Donev, A., Connelly, R., Stillinger, F.H. and Torquato, S. (2007), "Underconstrained jammed packings of nonspherical hard particles: Ellipses and ellipsoids", Phys. Rev. E, 75(5), 05130451. http://doi.org/ 10.1103/PhysRevE.75.051304.
  8. Flitti, A., Della, N., De Kock, T., Cnudde, V. and Verastegui-Flores, R.D. (2019), "Effect of initial fabric on the undrained response of clean Chlef sand", Eur. J. Environ. Civ. Eng., 1-16. http://doi.org/10.1080/19648189.2019.1631217.
  9. Fu, P. and Dafalias, Y.F. (2011), "Study of anisotropic shear strength of granular materials using DEM simulation", Int. J. Numer. Anal. Meth, 35(10), 1098-1126. http://doi.org/10.1002/nag.945.
  10. Gong, J, and Liu, J. (2017), "Mechanical transitional behavior of binary mixtures via DEM: Effect of differences in contact-type friction coefficients", Comput. Geotech., 85, 1-14. http://doi.org/ 10.1016/j.compgeo.2016.12.009.
  11. Gong, J. and Liu, J. (2017), "Effect of aspect ratio on triaxial compression of multi-sphere ellipsoid assemblies simulated using a discrete element method", Particuology, 32, 49-62. http://doi.org/ 10.1016/j.partic.2016.07.007.
  12. Gong, J., Jun, L. and Liang, C. (2019b), "Shear behaviors of granular mixtures of gravel-shaped coarse and spherical fine particles investigated via discrete element method", Powder Technol., 353, 178-194. http://doi.org/10.1016/j.powtec.2019.05.016.
  13. Gong, J., Wang, X., Li, L. and Nie, Z. (2019a), "DEM study of the effect of fines content on the small-strain stiffness of gap-graded soils", Comput. Geotech., 112, 35-40. http://doi.org/ 10.1016/j.compgco.2019.04.008.
  14. Goudarzy, M., Koenig, D. and Schanz, T. (2016), "Small strain stiffness of granular materials containing fines", Soils Found., 56(5), 756-764. http://doi.org/10.1016/j.sandf.2016.08.002.
  15. Gu, X.Q. and Yang, S. (2018), "Why the OCR may reduce the small strain shear stiffness of granular materials?", Acta Geotech., 13(6), 1467-1472. http://doi.org/10.1007/s11440-018-0695-9.
  16. Gu, X.Q., Lu, L. and Qian, J. (2017), "Discrete element modeling of the effect of particle size distribution on the small strain stiffness of granular soils", Particuology, 32, 21-29. http://doi.org/ 10.1016/j.partic.2016.08.002.
  17. Guo, P. (2008), "Modified direct shear test for anisotropic strength of sand", J. Geotech. Geoenviron. Eng., 134(9), 1311-1318. http://doi.org/10.1061/(ASCE)1090-0241(2008)134:9(1311).
  18. Hardin, B.O. and Richart, F.E. (1963), "Elastic wave velocities in granular soils", J. Soil Mech. Found. Div., 89(SM1), 39-56. https://doi.org/10.1061/JSFEAQ.0000558
  19. Hoque, E. and Tatsuoka, F. (1998), "Anisotropy in elastic deformation of granular materials", Soils Found., 38(1), 163-179. http://doi.org/10.3208/sandf.38.163.
  20. Itasca. (2014), User's manual for PFC3D, Itasca Consulting Group, Inc., Minneapolis, Minnesota, U.S.A.
  21. Iwasaki, T. and Tatsuoka, F. (1977), "Effects of grain size and grading on dynamic shear moduli of sands", Soils Found., 3(17), 19-35. http://doi.org/10.3208/sandf1972.17.3_19.
  22. Jiang, M. Zhang, A. and Fu, C. (2018), "3D DEM simulations of drained triaxial tests on inherently anisotropic granulates", Eur. J. Environ. Civ. Eng., 221(SI), s37-s56. http://doi.org/10.1080/19648189.2017.1385541.
  23. Kokusho, T. (1980), "Cyclic triaxial test of dynamic soil properties for wide strain range", Soils Found., 2(20), 45-60. http://doi.org/10.1016/0148-9062(81)91053-6.
  24. Kumar, J. and Madhusudhan, B.N. (2010), "Effect of relative density and confining pressure on Poisson ratio from bender and extender elements tests", Geotechnique, 60(7), 561-567. http://doi.org/ 10.1680/geot.9.T.003.
  25. Kumara, J.J. and Hayano, K. (2016), "Importance of particle shape on stress-strain behaviour of crushed stone-sand mixture", Geomech. Eng., 10(4), 455-470. http://doi.org/10.12989/gae.2016.10.4.455.
  26. Li, B. and Zeng, X. (2014), "Effects of fabric anisotropy on elastic shear modulus of granular soils", Earthq. Eng. Eng. Vib., 13(2), 269-278. http://doi.org/10.1007/s11803-014-0229-x.
  27. Li, B., Zeng, X. and Yu, H. (2014), "Characterization of liquefaction resistance of sand: Effect of initial fabric", J. Earthq. Tsunami, 8(1), 14500011. http://doi.org/10.1142/S1793431114500018.
  28. Liu, X. and Yang, J. (2018). "Shear wave velocity in sand: Effect of grain shape", Geotechnique, 68(8), 742-748. http://doi.org/10.1680/jgeot.17.T.011.
  29. Lo Prresti, D.C.F., Jamiolkowski, M., Parrara, O. and Predroni, A.C.S. (1997), "Shear modulus and damping of soils", Geotechnique, 3(47), 603-617. http://doi.org/10.1680/geot.1997.47.3.603.
  30. Magnanimo, V., La Ragione, L., Jenkins, J.T., Wang, P. and Makse, H.A. (2008), "Characterizing the shear and bulk moduli of an idealized granular material", Europhys. Lett., 81(3), 340063. http://doi.org/10.1209/0295-5075/81/34006.
  31. Mitchell, J. and Soga, K. (2005), Fundamentals of Soil Behavior, John Wiley & Sons, New York, U.S.A.
  32. Nguyen, C., O'Sullivan, C. and Otsubo, M. (2018), "Discrete element method analysis of small-strain stiffness under anisotropic stress states", Geotechnique Lett., 8(3), 183-189. https://doi.org/10.1680/jgele.17.00122.
  33. Patel, A., Bartake, P.P. and Singh, D.N. (2008), "An empirical relationship for determining shear wave velocity in granular materials accounting for grain morphology", Geotech. Test. J., 32(1), 1-10. http://doi.org/ 10.1520/GTJ100796.
  34. Qian, J., Yao, Y., Li, J., Xiao, H.B. and Luo, S.P. (2020), "Resilient properties of soil-rock mixtures materials: Preliminary investigation of the effect of composition and structure", Materials, 13(7), 1658, http://doi.org/10.3390/ma13071658.
  35. Qu, T.M., Feng, Y.T., Wang, Y. and Wang, M. (2019), "Discrete element modelling of flexible membrane boundaries for triaxial tests", Comput. Geotech., 115, 103154. http://doi.org/10.1016/j.compgeo.2019.103154.
  36. Rahman, M.M., Nguyen, H.B.K. and Rabbi, A.T.M.Z. (2018), "The effect of consolidation on undrained behaviour of granular materials: Experiment and DEM simulation", Geotech. Res., 5(4), 199-217. http://doi.org/10.1680/jgere.17.00019.
  37. Stahl, M. and Konietzky, H. (2011), "Discrete element simulation of ballast and gravel under special consideration of grain-shape, grain-size and relative density", Granul. Matter, 13(4), 417-428. http://doi.org/10.1007/s10035-010-0239-y.
  38. Tong, Z., Fu, P., Zhou, S. and Dafalias, Y.F. (2014), "Experimental investigation of shear strength of sands with inherent fabric anisotropy", Acta Geotech., 9(2), 257-275. http://doi.org/10.1007/s11440-014-0303-6.
  39. Wichtmann, T. and Triantafyllidis, T. (2009), "Influence of the grain-size distribution curve of quartz sand on the small strain shear modulus Gmax", J. Geotech. Geoenviron. Eng., 135(10), 1404-1418. http://doi.org/10.1061/(ASCE)GT.1943-5606.0000096.
  40. Yamashita, S., Hori, T. and Suzuki, T. (2005), "Effects of initial and induced anisotropy on initial stiffness of sand by triaxial and bender elements tests", Proceedings of the 1st Japan-U.S. Workshop on Testing, Modeling, and Simulation, Boston, Massachusetts, U.S.A., June.
  41. Yang, J. and Gu, X.Q. (2013), "Shear stiffness of granular material at small strains: Does it depend on grain size?", Geotechnique, 63(2), 165-179. http://doi.org/10.1680/geot.11.P.083.
  42. Yang, J. and Liu, X. (2016), "Shear wave velocity and stiffness of sand: The role of non-plastic fines", Geotechnique, 66(6), 500-514. http://doi.org/10.1680/jgeot.15.P.205.
  43. Yang, J., Liu, X., Rahman, M.M., Lo, R., Goudarzy, M. and Schanz, T. (2018), "Shear wave velocity and stiffness of sand: The role of non-plastic fines", Geotechnique, 68(10), 931-934. http://doi.org/ 10.1680/jgeot.15.P.205.
  44. Yang, Z.X., Yang, J. and Wang, L.Z. (2013), "Micro-scale modeling of anisotropy effects on undrained behavior of granular soils", Granul. Matter, 15(5), 557-572. http://doi.org/10.1007/s10035-013-0429-5.
  45. Yu, H., Zeng, X., Li, B. and Ming, H. (2013), "Effect of Fabric Anisotropy on Liquefaction of Sand", J. Geotech. Geoenviron. Eng., 139(5), 765-774. http://doi.org/10.1061/(ASCE)GT.1943-5606.0000807.
  46. Zhao, S., Zhang, N., Zhou, X. and Zhang, L. (2017), "Particle shape effects on fabric of granular random packing", Powder Technol., 310, 175-186. http://doi.org/10.1016/j.powtec.2016.12.094.
  47. Zhou, Z.Y., Zou, R.P. and Pinson, D. (2011), "Dynamic simulation of the packing of ellipsoidal particles", Industr. Eng. Chem. Res., 50(16), 9787-9798. http://doi.org/10.1021/ie200862n.