Design approaches for geotextile separators beneath the granular sub-bases of unpaved roads Available to Purchase

The purpose of a geotextile separator beneath a granular sub-baisse to prevent the road aggregate and the underlying subgrade soil from intermixing. In the absence of a geotextile, contamination of the sub-base aggregate by soft subgrade soil could reduce its load bearing capacity and thereby limit the life of the pavement

A number of different approaches have been proposed for the design of geotextile separators beneath unpaved roads. The most widely accepted of the methods based on simple hand calculations are those of Giroud and Noiray, and Sellmeijer et al. This Technical Note presents a simplified summary of these two design approaches and suggests some modifications.