Modified Green–Ampt Model for Modeling Water Flow Behavior in Capillary Barrier System

Extensive research studies related to capillary barrier system (CBS) in the literature showcased its effective antiseepage water characteristics for improving the performance of several soil infrastructures. In this study, a series of model tests were conducted to investigate the water flow behavior within CBS. Based on the careful interpretation of experimental results, the water flow behavior in CBS is divided into two distinct processes: infiltration and reinfiltration processes. In addition, a mathematical model is proposed by modifying Green–Ampt’s (GA) model that describes three distinct stages of water flow processes associated with wetting front variation, which are referred to as wetting front development stage, advanced stage, and termination stage. The proposed model is successfully validated using the performed laboratory experiments. The calculation results of the modified GA model show an error of only 3.92% compared with the experimental results, which is significantly lower than that of the traditional GA model. In summary, the proposed model is promising for use as a tool in the rational design of CBS that can be used to alleviate or reduce the impact of landslides, basal erosion, percolation of tailings, and landfills considering the site geological conditions.