GRANULAR BASE MODULI FOR MECHANISTIC PAVEMENT DESIGN.

Simple stress dependent granular material models are proposed to predict the aggregate cross-anisotropic responses observed in flexible airport pavements. A cross-anisotropic representation has different material properties (i.e., elastic modulus and Poisson's ratio) assigned in the horizontal and vertical directions. Repeated load triaxial tests with vertical and lateral deformation measurements are used for establishing these anisotropic properties. Flexible pavement responses predicted under one wheel of the Boeing 777-200A aircraft using the anisotropic model are found to be higher than LEDFAA response variables. A sensitivity analysis shows, in general, that as aggregate base horizontal and shear stiffnesses increases, the critical pavement responses decreases to some extent.