Assessing the Influence of Soil-Reinforcement Interaction Parameters on the Performance of a Low Fill on Compressible Subgrade. Part II: Influence of Surface Maintenance

Geosynthetics can be effectively used as reinforcement of low fills on weak subgrades, as is the case of unpaved roads. They can reduce fill deformation and increase its life. This paper investigates the performance of unreinforced and reinforced low fills on a loose sand subgrade, with particular emphasis on the behaviour of the fills after surface maintenance. Different types of geosynthetics (12 geogrids and a woven geotextile) were tested in a large equipment where the fills were subjected to cyclic loading. The results obtained showed that the presence of the reinforcement improved the performance of the fill during the first and second (after surface maintenance) loading stages. The gain in performance depended on the reinforcement type and characteristics. Optimum ranges for the ratio between geogrid aperture dimension and fill particle diameter were identified for which less fill particle breakage and greater load spreading angles were obtained. The results show that the specification of a geogrid reinforcement for applications such as in unpaved roads or railway tracks based on its tensile stiffness is necessary but not sufficient to obtain maximum efficiency from the reinforcement.