An integrated approach for validating unsaturated soil parameters in seepage analyses

Soil–water characteristic curves (SWCCs) and soil permeability functions (SPFs) for a silty sand were validated based on soil suction and soil water content measurements in calibration box and constant-head seepage tests. Transient seepage analyses using finite element method (FEM) were performed to examine the accuracy of the derived SWCCs and SPFs, with a special focus on the wetting front propagation. Results show that the proposed new integrated system consisting of experimental and analytical techniques works well, in the sense that the soil moisture responses at specific depths of soil mimic those measured in constant-head seepage tests.

► An integrated approach for validating soil–water characteristic curves and soil permeability functions is proposed.
► Soil–water characteristic curves of the studied sand were obtained via calibration box tests.
► The experimental soil–water characteristic curve was best-fitted using Fredlund and Xing’s numerical model.
► The permeability function of the studied sand was identified based on the result of finite element analyses.