Determination of Soil-Shrinkage Curve Using Transient Water Evaporation Method

Abstract

Soil-shrinkage curve (SSC) is an intrinsic constitutive relationship characterizing soil deformation due to variation of water content under drying. The determination of SSC has been challenging due to the difficulty of accurate measurement of volume change and the access of a broad range of water content. In this study, SSCs of three different types of soils are measured successfully by image process on photos of soil cake samples under multiple steps of drying in a humidity-controlled environmental chamber. The development of volumetric, radial, and vertical strain, and the geometry factor of the deformation are analyzed to validate homogeneous shrinkage during the entire drying process. The soil deformation is analyzed on the effect of transient drying and its dependency on water content. The sensitivity of mechanical and hydraulic properties of soil responding to time concludes that the equilibrium is not a necessity for the mechanical property measurement such as SSC. This feature implies that a transient drying process can be implemented to significantly shorten the time duration for measurement of soil shrinkage without an equilibrium condition in soil desiccation.