Mechanistic Design of Low Volume Road Structures

Abstract

This paper presents a new design approach for assessing the risk of excessive
permanent deformation development in soft subgrade soil underlying a low volume road of
thin structural layers exposed to heavy wheel loads i.e. Mode 2 rutting using the terminology
defined in the EU-funded ROADEX project. The approach is essentially based on backcalculating
the results of 3D Finite Element modelling produced with the PLAXIS software
package in a way that allows obtaining the same result in terms of ultimate load carrying
capacity of the subgrade soil by a simple hand-calculation procedure as would be obtained by
sophisticated 3D FE modelling of the loading arrangement / road structure / subgrade soil
combination in question.