Importance of Nonlinear Anisotropic Modeling of Granular Base for Predicting Maximum Viscoelastic Pavement Responses under Moving Vehicular Loading

Abstract

AbstractThis paper explains the importance of using a nonlinear anisotropic three-dimensional (3D) finite-element (FE) pavement model to simulate the granular base layer and predict viscoelastic pavement responses under moving vehicular loading. The FE model was built using the general-purpose FE software ABAQUS, and a user material subroutine was developed to implement the constitutive model of granular material using a modified Newton-Raphson approach with secant stiffness. The FE model utilizes implicit dynamic analysis and simulates the vehicular loading as a moving load with 3D contact stresses at the tire-pavement interface. The analysis results indicate that it is important to consider the viscoelastic nature of the asphalt layer and the moving load for accurately capturing the nonlinear granular base modulus in the mechanistic pavement model. The modulus distribution in the granular base layer is affected not only by wheel load and pavement structure (such as asphalt layer thickness and subgrade s...