Micromechanical model of weakly-cemented sediments

    Research output: Contribution to journalArticlepeer-review

    6 Citations (Scopus)
    8 Downloads (Pure)

    Abstract

    Experiments indicate that the bulk stiffness of weakly‐cemented granular materials increases significantly with the applied load, a nonlinearity which is not captured by most micromechanical models. Here, we study the deformation of weakly‐cemented materials through grain‐scale simulations. We show that the frequently‐made assumption of linear‐elastic cement and intergranular contact area which varies according to a Hertzian‐type model cannot explain the observed nonlinearity of the bulk response. We introduce the micromechanical effect of mechanisms such as closure and opening of microcracks, granular cement and material heterogeneity through an effective contact stiffness which depends on the local deformation. We find that an exponential dependence between the effective stiffness and the local deformation, with a high exponent value, provides bulk stiffness which is in good agreement with experimental data. The inability of models with weaker intergranular stiffness‐deformation dependence to reproduce the experimental data demonstrates the highly‐nonlinear nature of the intergranular deformation. Our results highlight the importance of accounting for grain‐scale mechanisms in modeling granular materials, and provide a plausible explanation for the nonlinear behavior of weakly‐cemented sediments.
    Original languageEnglish
    Pages (from-to)944-958
    Number of pages15
    JournalInternational Journal for Numerical and Analytical Methods in Geomechanics
    Volume37
    Issue number7
    Early online date17 Mar 2012
    DOIs
    Publication statusPublished - May 2012

    Keywords

    • Nonlinear deformation
    • Grain-scale simulations
    • Intergranular slip
    • Hertz contact
    • Macroscopic elastic moduli
    • Bulk stiffness

    Fingerprint

    Dive into the research topics of 'Micromechanical model of weakly-cemented sediments'. Together they form a unique fingerprint.

    Cite this