Desiccation shrinkage of unconstrained soil in the saturated phase

Analysis of macroscopic desiccation shrinkage experiments indicates that most of the shrinkage occurs during drying while soil is still 100% wet. When air starts penetrating the soil, shrinkage practically ceases, while the water content is still above 20%. The remaining drying process occurs with a much-reduced shrinkage. In this context we look at the data of pore space evolution during saturated phase of drying as obtained via porosimetry. The observed behavior is modeled at a microscale using Poiseuille flow in capillary vessels with deformable walls driven by evaporation flux at the external boundary. A macroscopic model using Biot and Darcy theories for the continuum were recently presented by the authors. © 2008 Taylor & Francis Group, London.