Modélisation de l'orniérage des chaussées à faible trafic

Rutting, due to permanent deformations of unbound materials, is one of the principal damage modes for low traffic pavements. Actually, the design methods are based on linear elasticity. The objective of this paper is to use a simplified method, based on the concept of the shakedown theory developed by Zarka for metallic structures under cyclic loadings, to estimate the permanent deformations of unbound granular materials (UGM) subjected to traffic loading. Based on repeated loading triaxial tests, a general procedure has been developed for the determination of the material parameters of the constitutive model. Finally, the results of a finite elements modelling of the long-term behaviour of a flexible pavement with the simplified method are presented. The mechanical initial states of granular layers are taken into account with an anisotropic hyperelastic model and the calculation of the rut depth evolution with time is carried out. Mots-clefs : Chaussee a faible trafic ; ornierage ; theorie de l’etat limite