A New Model Using Dynamic Contact Angle to Predict Hysteretic Soil Water Retention Curve

Core Ideas We predicted the initial drying, main wetting, main drying, water retention, and scanning curves. The model uses a process‐dependent contact angle determination. An experimental water retention curve was determined on clayey soils in slurry form. We present a water retention model able to predict the hysteretic response of soils during wetting–drying cycles. This model is an extension of the original Arya–Paris (AP) model. We improved the model—first by linking the empirical parameter in the AP model, a soil water retention model, to physical properties of the soil, like tortuosity, porosity, and the air‐entry point, and second by including the influence of hydraulic hysteresis through calculating the liquid–solid advancing and receding contact angles and taking into account the influence of volume change directly by considering the evolution of the soil water retention curves with void ratio variation. We assumed that the cyclic drying–wetting paths would depend on both void ratio and contact angle determination. Finally, our model performances were validated by comparison with experimental results on three soils in slurry form—two clays and a silty sand—and data from the literature for Hostun sand.