Capillary Effects in Polydisperse Systems and Their Use in Soil Engineering

Abstract: The capillary effect in polydisperse porous systems of soils and sediments is discussed. This effect is quantified using a new fundamental model of capillary rise depending on the parameters of dispersion of soil particles, soil bulk density, density of soil solid phase, wettability, and the amount of tightly bound water. In contrast to a well-known Jurin’s law, the model takes into account the particle-size distributions and the change in pore size associated with soil density. The model adequately predicts the capillary rise in both artificial monodisperse porous systems and real soils with the particle size ranging from 0.006 to 1 mm. The effects of natural and synthetic hydrophobizers on the kinetics and maximum height of capillary rise are examined. The laboratory and field data on the efficiency of imperfect (with hydraulic connection) and perfect (with its rupture) capillary barriers are compared to the Hydrus-1D predictive modeling data. The results are used to evaluate the capillarity in soils and to design soil constructions with capillary barriers. © 2021, Pleiades Publishing, Ltd.