Drying-Induced Consolidation in Soil

Drying-induced consolidation in soil is defined as volumetric shrinkage by interparticle stresses (suction stress) during drying under conditions of zero external or total stress. A new analysis is presented to synthesize recently published and new experimental data for soil water retention, shrinkage, physicochemical properties, and index properties for a broad range of soils ranging from nonexpansive to highly expansive. The suction stress characteristic curves of these soils are computed and compared using two deformation-based methods: the previously established discretized element solution and a simpler bulk-volume solution. Drying-induced consolidation for unsaturated soils exhibits a similar behavior to traditional consolidation behavior for saturated soils. The demonstrated strong correlations between the compression index and soil water retention characteristics and between the compression index and geotechnical index properties provide rational linkages between the fundamental soil properties and bulk deformation properties, where in this case the compression index is defined as the slope of the void ratio versus logarithm of negative suction stress relationship. These correlations are expected to be useful as new fundamental index properties for soil classification and for geotechnical applications involving desiccation and volume change.