Use of In Situ Air Flow Measurements to Study Permeability in Cracked Clay Soils

T. Wells, S. Fityus, David Smith

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    5 Citations (Scopus)

    Abstract

    The work describes in situ measurements of crack induced permeability as a function of depth, (down to ∼ 1.75 m), in clay soils at two field sites, using the gas flow technique described in an earlier study. The gas flow response to applied pressure was found to exhibit a significant nonlinearity at all depths indicating non-Darcian flow despite the fact that the flow was likely to be well within the laminar flow regime. Application of three-dimensional finite-element models to describe the gas flow revealed that the nonlinearity is likely to be an intrinsic behavior related to the soil-gas flow interaction. The Forchheimer compressible flow equation successfully simulated the behavior at all depths. The viscous and inertial permeability parameters obtained from this analysis showed a wide range of values which were closely correlated to the pore-water content of the soil medium, clearly showing the influence of ped swelling on the contraction of macrovoid channels in the structured clay soil.
    Original languageEnglish
    Pages (from-to)1577-1586
    JournalJournal of Geotechnical and Geoenvironmental Engineering
    Volume133
    Issue number12
    DOIs
    Publication statusPublished - 2007

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