Prediction of permanent deformations of unbound pavement layers

Abstract

This paper presents a simplified method for modelling of permanent deformations of unbound granular pavement layers, using finite element calculations. This method is based on a model of prediction of permanent deformations of unbound granular materials, developped from repeated load triaxial testing [Gidel, 2001]. The permanent deformations in the pavement structure are calculated in two steps : The first step consists in modelling the resilient behaviour, using non linear elastic models, to determine the stress field in the pavement. The second step consists in using the stress paths obtained at different points in the pavement structure to calculate the permanent strains, using the permanent deformation model. The approach is used to predict the rutting of a low traffic pavement structure, with unbound granular base, tested on the LCPC accelerated testing facility.