Influence of cross-anisotropy material behavior on back-calculation analysis of multi-layered systems

Abstract

Each layer in a pavement structure is compacted during construction. Moreover, since the compaction process is carried along the same direction, it is well known that horizontal and vertical mechanical properties in each layer differ. But when FWD test results are analyzed, it is assumed that layer properties are homogenous and isotropic. The influence of anisotropic material property on pavement performance has never been evaluated. In this research, pavement base layer materials are assumed to be cross-anisotropic and by assuming a variety of horizontal and vertical elastic moduli, surface deflections were computed. These deflections were used to backcalculate equivalent layer moduli assuming isotropic material property. Finally, by using standard performance prediction models, results for the case of cross-anisotropic and isotropic base materials were compared