Efficient laboratory measurements of the soil water retention curve

The knowledge of the soil water retention curve (SWRC) is of particular importance for unsaturated soils. However common techniques to determine SWRC may be much more time-consuming than other soil property testing techniques and may lack flexibility in controlling the stress state of the soil in the field, which is of most relevance for geotechnical engineering applications. The paper presents a transient testing technique for the continuous measurement of SWRC in a triaxial cell during which testing rates are adjusted based on numerical modeling results simulating the testing. This enables the optimization of the experimental process and hence a more efficient determination of the SWRC. The technique is then successfully applied to determine the SWRC of statically compacted silica flour specimens, tested under different confining stresses.