DOI QR코드

DOI QR Code

Effect of particle size on direct shear deformation of soil

  • Gu, Renguo (State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences) ;
  • Fang, Yingguang (South China University of Technology) ;
  • Jiang, Quan (State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences) ;
  • Li, Bo (South China University of Technology) ;
  • Feng, Deluan (Guangdong University of Technology)
  • Received : 2021.05.10
  • Accepted : 2021.09.14
  • Published : 2022.01.25

Abstract

Soils are natural granular materials whose mechanical properties differ according to the size and composition of the particles, so soils exhibit an obvious scale effect. Traditional soil mechanics is based on continuum mechanics, which can not reflect the impact of particle size on soil mechanics. On that basis, a matrix-reinforcing-particle cell model is established in which the reinforcing particles are larger-diameter sand particles and the matrix comprises smaller-diameter bentonite particles. Since these two types of particles deform differently under shear stress, a new shear-strength theory under direct shear that considers the stress concentration and bypass phenomena of the matrix is established. In order to verify the rationality of this theory, a series of direct shear tests with different reinforcing particle diameter and volume fraction ratio are carried out. Theoretical analysis and experimental results showed that the interaction among particles of differing size and composition is the basic reason for the size effect of soils. Furthermore, the stress concentration and bypass phenomena of the matrix enhance the shear strength of a soil, and the volume ratio of reinforcing particles has an obvious impact on the shear strength. In addition, the newly proposed shear-strength theory agrees well with experimental values.

Keywords

Acknowledgement

This work was supported by the Open Research Fund of the State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences (Grant No. Z018019), the State Key Laboratory of Subtropical Building Science, South China University of Technology (Grant No. 2017KB16), and the National Key Scientific Instruments and Equipment Development Projects of China (Grant No. 41827807).

References

  1. Aziz, M. (2020), "Using grain size to predict engineering properties of natural sands in Pakistan", Geomech. Eng., 22(2), 165-171. https://doi.org/10.12989/gae.2020.22.2.165.
  2. Ba Ant, Z.P. (1999), "Size effect on structural strength: a review", Arch. Appl. Mech., 69(9-10), 703-725. https://doi.org/10.1007/s004190050252.
  3. Ballesteros Canovas, J.A., Stoffel, M., Corona, C., Schraml, K., Gobiet, A., Tani, S., Sinabell, F., Fuchs, S. and Kaitna, R. (2016), "Debris-flow risk analysis in a managed torrent based on a stochastic life-cycle performance", Sci. Total Environ., 557-558, 142-153. https://doi.org/10.1016/j.scitotenv.2016.03.036.
  4. Christoph, M., Weissbach, R., Weinberg, J., Wall, W.A. and Hart, A.J. (2019), "Modeling and characterization of cohesion in fine metal powders with a focus on additive manufacturing process simulations", Powder Technol., 343, 855-866. https://doi.org/10.1016/j.powtec.2018.11.072.
  5. Cundall, P.A. and Strack, O.D.L. (1980), "Discussion: A discrete numerical model for granular assemblies", Geotechnique, 30(3), 331-336. https://doi.org/10.1680/geot.1980.30.3.331.
  6. Drucker, D.C. and Prager, W. (1952), "Soil mechanics and plastic analysis or limit design", Q. Appl. Math., 10(2), 157-165. https://doi.org/10.1090/qam/48291.
  7. Fang, Y. (2014a), "Theoretical and experimental investigation on size effect characteristic of strength and deformation of soil", Yantu Lixue/Rock Soil Mech., 35(1), 41-47. https://doi.org/10.7498/aps.63.034502.
  8. Fang, Y. (2014b), "Shear test and physical mechanism analysis on size effect of granular media", Wuli Xuebao/Acta Physica Sinica, 63(3), 274-283. https://doi.org/10.7498/aps.63.034502.
  9. Fang, Y.G. and Bo, L. (2016), "Multiscale problems and analysis of soil mechanics", Mech. Mater., 103, 55-67. https://doi.org/10.1016/j.mechmat.2016.09.003.
  10. Herrmann, H.J. (2001), "Granular matter", Proceedings of the 10th International Summer School on Fundamental Problems in Statistical Physics Altenberg Germany, August.
  11. Iverson, R.M. (1997), "The physics of debris flows", Rev. Geophys., 35(3), 245-296. https://doi.org/10.1029/97RG00426.
  12. Jia, M.C., Liu, B., Xue, J.F. and Ma, G.Q. (2020), "Coupled three-dimensional discrete element-finite difference simulation of dynamic compaction", Acta Geotech. https://doi.org/10.1007/s11440-020-01055-y.
  13. Jiang, Y. and Liu, M. (2003), "Granular elasticity without the Coulomb condition", Phys. Rev. Lett., 91(14), 144301. https://doi.org/10.1103/PhysRevLett.91.144301.
  14. Kanchi, G.M., Neeraja, V.S. and Babu, G.L.S. (2015), "Effect of anisotropy of fibers on the stress-strain response of fiber-reinforced soil", Int. J. Geomech., 15(1), 06014016. https://doi.org/10.1061/(ASCE)GM.1943-5622.0000392.
  15. Kuhn, M.R. (2005), "Are granular materials simple? An experimental study of strain gradient effects and localization", Mech. Mater., 37(5), 607-627. https://doi.org/10.1016/j.mechmat.2004.05.001.
  16. Liu, D. and Yang, J. (2020), "Efficient flexible boundary algorithms for DEM simulations of biaxial and triaxial tests", Geomech. Eng., 23(3), 189-206. https://doi.org/10.12989/gae.2020.23.3.189.
  17. Mishra, B.K. (2003), "A review of computer simulation of tumbling mills by the discrete element method: Part I-contact mechanics", Int. J. Miner. Process., 71(1-4), 73-93. https://doi.org/10.1016/S0301-7516(03)00031-0.
  18. Mitchell, J.K. and Soga, K. (2005), Fundamentals of Soil Behavior, (3rd Edition), John Wiley and Sons Inc., New York. NY, USA.
  19. Morgan, J.K. (1999), "Numerical simulations of granular shear zones using the distinct element method - 2. Effects of particle size distribution and interparticle friction on mechanical behavior", J. Geophys. Res. Solid Earth, 104(2), 2721-2732. https://doi.org/10.1029/1998JB900055.
  20. Morgan, J.K. and Boettcher, M.S. (1999), "Numerical simulations of granular shear zones using the distinct element method: 1. Shear zone kinematics and the micromechanics of localization", J. Geophys. Res. Solid Earth, 104(2), 2703-2719. https://doi.org/10.1029/1998JB900056
  21. Nicot, F.O., Sibille, L., Donze, F. and Darve, F. (2007), "From microscopic to macroscopic second-order work in granular assemblies", Mech. Mater., 39(7), 664-684. https://doi.org/10.1016/j.mechmat.2006.10.003.
  22. Norouzi, H.R., Zarghami, R., Sotudeh-Gharebagh, R. and Mostoufi, N. (2016), Coupled CFD-DEM Modeling: Formulation, Implementation and Application to Multiphase Flows. John Wiley and Sons Inc., New York. NY, USA.
  23. Oda, M. and Kazama, H. (1998), "Microstructure of shear bands and its relation to the mechanisms of dilatancy and failure of dense granular soils", Geotechnique, 48(4), 465-481. https://doi.org/10.1680/geot.1998.48.4.465.
  24. Onturk, K., Bol, E., Ozocak, A. and Edil, T.B. (2020), "Effect of grain size on the shear strength of unsaturated silty soils", Geomech. Eng., 23(4), 301-311. https://doi.org/10.12989/GAE.2020.23.4.301.
  25. Park, T.W., Kim, H.J., Tanvir, M.T., Lee, J.B. and Moon, S.G. (2018), "Influence of coarse particles on the physical properties and quick undrained shear strength of fine-grained soils", Geomech. Eng., 14(1), 99-105. https://doi.org/10.12989/gae.2018.14.1.099
  26. Roscoe, K.H., Schofield, A.N. and Thurairajah, A., (1963), "Yielding of clays in state wetter than critical",Geotechnique, 13(3), 21-40. https://doi.org/10.1680/geot.1963.13.3.211.
  27. Vardoulakis, I. and Muhlhaus, H.B. (1987), "The thickness of shear bands in granular materials", Geotechnique, 37(3), 271-283. https://doi.org/10.1680/geot.1987.37.3.271.
  28. Zheng, H., Zhang, P. and Du, X. (2016), "Dual form of discontinuous deformation analysis", Comput. Method. Appl. M., 305, 196-216, https://doi.org/10.1016/j.cma.2016.03.008.