Structural response of an inverted pavement with stabilised base by numerical approach considering isotropic and anisotropic properties of unbound layers

Inverted pavements or inverted base pavements are defined by the presence of stiffer supporting layers below the top bituminous layer, which is contrary to the conventional flexible pavements, where the stiffness of the layers decrease with depth. Response of an inverted pavement depends on the relative stiffness of the successive layers. Therefore mechanistic design of inverted pavements demand analysis of the pavements using realistic elastic parameters of the layers. Studies on unbound granular layers have established the anisotropic properties of the layer that better correlates with the field performance. The present study aims at evaluating structural responses of an inverted pavement using finite element based modelling that considers anisotropic properties of the unbound materials i.e. aggregate interlayer and subgrade. Results show that anisotropy of the aggregate interlayer has a larger role to play in the design on inverted pavements having provision of aggregate interlayers.