Spatial state distribution and phase transition of non-uniform water in soils: Implications for engineering and environmental sciences

Lianhai Zhang*, Qianlai Zhuang, Zhi Wen, Peng Zhang, Wei Ma, Qingbai Wu, Hanbo Yun

*Corresponding author for this work

    Research output: Contribution to journalReviewResearchpeer-review

    16 Citations (Scopus)

    Abstract

    The physical behaviors of water in the interface are the fundamental to discovering the engineering properties and environmental effects of aqueous porous media (e.g., soils). The pore water pressure (PWP) is a key parameter to characterize the pore water state (PWS) and its phase transition in the micro interface. Traditionally, the water in the interface is frequently believed to be uniform, negative in pressure and tensile based on macroscopic tests and Gibbs interface model. However, the water in the interface is a non-uniform and compressible fluid (part of tensile and part of compressed), forming a spatial profile of density and PWP depending on its distance from the substrate interface. Herein, we introduced the static and dynamic theory methods of non-uniform water based on diffuse interface model to analyze non-uniform water state dynamics and water density and PWP. Based on the theory of non-uniform water, we gave a clear stress analysis on soil water and developed the concepts of PWS, PWP and matric potential in classical soil mechanics. In addition, the phase transition theory of non-uniform water is also examined. In nature, the generalized Clausius-Clapeyron equation (GCCE) is consistent with Clapeyron equation. Therefore, a unified interpretation is proposed to justify the use of GCCE to represent frozen soil water dynamics. Furthermore, the PWP description of non-uniform water can be well verified by some experiments focusing on property variations in the interface area, including the spatial water density profile and unfrozen water content variations with decreasing temperature and other factors. In turn, PWP spatial distribution of non-uniform water and its states can well explain some key phenomena on phase transition during ice or hydrate formation, including the discrepancies of phase transition under a wide range of conditions

    Original languageEnglish
    Article number102465
    JournalAdvances in Colloid and Interface Science
    Volume294
    Number of pages12
    ISSN0001-8686
    DOIs
    Publication statusPublished - Aug 2021

    Bibliographical note

    CENPERM[2021]

    Keywords

    • Diffuse interface model
    • GCCE
    • Hydrate formation
    • Matric potential
    • Non-uniform water
    • Phase transition

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