Nonlinear numerical simulation of rainwater infiltration through road embankments by FEM

This paper presents the results of nonlinear numerical simulations carried out to analyze rainwater infiltration through a road embankment structure using the finite element method (FEM) technique. The analysis of this paper includes a simplification of a cross-sectional road embankment located in Santander (Northern Spain) and considers different realistic hydraulic material parameters, according to the relevant literature, in order to study their effect on water movement throughout the section over time. The model solved the nonlinear Richards’ equation using the constitutive relationships of van Genuchten–Mualem. Finally, the analysis of the numerical results reveals four main conclusions: (1) models based on FEM are suitable for analyzing rainwater infiltration in road structures, (2) the hard-shoulder area of the highway represents an important infiltration point for rainwater in road structures, (3) the embankment material can greatly affect the soil’s water content in this part of the road, and (4) the analysis of the soil water retention curve of the embankment material provides relevant information about its hydraulic behavior under unsaturated conditions.