A critical state sand plasticity model accounting for fabric evolution

Authors

  • Zhiwei Gao,

    1. Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Hong Kong
    Search for more papers by this author
  • Jidong Zhao,

    Corresponding author
    1. Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Hong Kong
    • Correspondence to: Jidong Zhao, Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong.

      E-mail: jzhao@ust.hk

    Search for more papers by this author
  • Xiang-Song Li,

    1. Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Hong Kong
    Search for more papers by this author
  • Yannis F. Dafalias

    1. Department of Civil and Environmental Engineering, University of California, Davis, CA, U.S.A.
    2. Department of Mechanics, School of Applied Mathematical and Physical Sciences, National Technical University of Athens, Athens, Greece
    Search for more papers by this author

SUMMARY

Fabric and its evolution need to be fully considered for effective modeling of the anisotropic behavior of cohesionless granular sand. In this study, a three-dimensional anisotropic model for granular material is proposed based on the anisotropic critical state theory recently proposed by Li & Dafalias [2012], in which the role of fabric evolution is highlighted. An explicit expression for the yield function is proposed in terms of the invariants and joint invariants of the normalized deviatoric stress ratio tensor and the deviatoric fabric tensor. A void-based fabric tensor that characterizes the average void size and its orientation of a granular assembly is employed in the model. Upon plastic loading, the material fabric is assumed to evolve continuously with its principal direction tending steadily towards the loading direction. A fabric evolution law is proposed to describe this behavior. With these considerations, a non-coaxial flow rule is naturally obtained. The model is shown to be capable of characterizing the complex anisotropic behavior of granular materials under monotonic loading conditions and meanwhile retains a relatively simple formulation for numerical implementation. The model predictions of typical behavior of both Toyoura sand and Fraser River sand compare well with experimental data. Copyright © 2013 John Wiley & Sons, Ltd.

Ancillary