Predicting hysteresis loops of the soil water characteristic curve from initial drying

Abstract

Abstract The soil water characteristic curve (SWCC) is an important tool in soil science and geotechnical applications. Most previous studies on SWCCs are limited to one to three drying‐wetting cycles, mainly because SWCC measurement is complex and time‐consuming. The numerous models that have been proposed to predict hysteresis in SWCCs. In this paper, a novel simplified equation is proposed based on the van Genuchten model, whereby SWCC hysteresis can be easily predicted from the initial drying SWCC. The theory for describing the main wetting curve and main drying curve considers the ink‐bottle effect and entrapped air. Laboratory experiments on silicon micro‐powder (SMP) and Guangxi Guiping clay (GGC) were conducted to determine SWCCs for five drying‐wetting cycles. The proposed equation was verified using the experimental SMP data and data from the literature. The predicted hysteretic SWCCs are in good agreement with the experimental data.