Modelling the Water Flow in Permeable Friction Course Pavement During Rainfall Considering Unsaturated Conductivity

Abstract This study presents a finite element modelling approach using the FEniCS platform to simulate transient water flow through permeable friction course (PFC) pavement during rainfall event, with a focus on unsaturated conductivity. In the body of PFC pavement, soil suction was calculated based on rainfall and used as an indicator of permeability. Using this approach, the parameters influencing water flow in the body of PFC were studied. Simulation results show that soil suction significantly affects the onset and magnitude of surface runoff: higher suction values correspond to increased permeability and a delayed the time taken to runoff. The findings filled the gap in the modelling for PFC pavement related to unsaturated conductivity dependence and offer insights into optimizing PFC design for improved stormwater management under varying infiltration conditions.