Analytical and numerical modelling of air trapping during wetting of unsaturated soils

At high values of degree saturation, the apparent soil water retention curve (SWRC) measured in a wetting test laboratory may differ from true SWRC, because occurrence air trapping, meaning that gas pressure trapped is greater than externally applied pressure. Physical arguments indicate SWRC will reach full saturation at positive value suction. Analytical and numerical modelling phenomenon trapping during shows that, once occurs, depends upon many aspects conditions not fundamental representation behaviour. The only correct way to represent influence within boundary problems use combination with conductivity expression goes zero air-discontinuity point.