Numerical Analysis of Unpaved Roads Subjected to Surface Maintenance
Geosynthetics, Unpaved Road, Surface Maintenance, Numerical Analysis
Geosynthetics have proven to be beneficial in reinforcing soils, especially in problems with large deformations, such as unpaved roads built on soft soils and subjected to high loads. Due to heavy machinery traffic, this situation occurs even during the construction period of the road, in which is necessary to perform surface maintenance for the execution of the fill layers. Several experimental studies have indicated an improvement in the mechanical performance of unpaved roads when subjected to surface maintenance. In this context, the present research aimed at studying, by means of the Finite Element Method, the behavior of unreinforced and reinforced unpaved roads subjected to surface maintenance. The analyses consisted of the following steps: determination of geostatic stresses in the subgrade; inclusion of the fill layer, as well as the geosynthetic reinforcement at the interface between the materials; application of a distributed load on the fill; unloading; execution of the surface maintenance from the deformed configuration of the fill; and reapplication of the load. The developed methodology was validated by comparisons with experimental results presented in the literature, indicating that these constructive steps allow a more realistic simulation of the mechanical behavior. The comparisons were made in terms of stress and displacement of the system at the base of the loading plate and the general behavior of total displacements, which reflect the influence of surface maintenance and geosynthetic reinforcement on the bearing capacity of the system and the observed failure mechanisms. Furthermore, relevant information was obtained as shear stresses mobilized in the system and deformation in the reinforcement. This was also studied by comparisons with data predicted empirically and by parametric analyses whose variables were height and stiffness of the embankment layer.