Analysis of flexible pavement with cross-anisotropic material properties

Abstract

Presently, there is a sway from empirical approaches to mechanistic-empirical based methods for pavement design, in which mechanistic pavement responses are related to the pavement performance. It provides a more rational approach for reliable prediction of the pavement distresses and pavement life. In mechanistic analysis, the materials are usually considered as linear elastic and isotropic, which is not realistic and rather exhibit a more complex behaviour. Finite element modelling (FEM) has the ability to handle this complex material properties, however it is time consuming and also needs expertise in this area. Therefore, multilayered linear elastic theory based programs are still favoured over FEM for analysis of flexible pavements. Most of the pavement materials (specifically the unbound materials) are anisotropic, however can be approximated as cross-anisotropic (different properties in vertical and horizontal directions) material. In this study, a multilayered linear elastic theory based program ‘CrossPave’ has been developed, which is capable of considering the cross-anisotropic behavior of the pavement materials. Through a comparison between isotropic and cross-anisotropic analysis of pavements, this study shows that isotropic analysis underestimates and some case overestimates the mechanistic parameters that may lead to incorrect pavement lives.