Modelling the effect of initial density on soil-water characteristic curves

This paper presents a simple approach to quantify the effect of initial soil density on the soil-water characteristic curve (SWCC) of unsaturated soils. This approach is based on an incremental relationship between the degree of saturation and the initial void ratio, which satisfies the intrinsic constraints for three-phase porous materials. The incremental relationship can be incorporated into existing SWCC equations to model the water retention behaviour for deformable soils. Only one additional parameter is introduced, which can be conveniently calibrated by way of conventional water retention tests. The SWCCs for the same soil at different initial void ratios can be found using the proposed approach. The proposed approach is validated against experimental data from drying tests for both compacted and reconstituted soils.