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

作者：Wang Hao^*; Al Qadi Imad L

来源：Journal of Engineering Mechanics, 2013, 139(1): 29-38.

DOI：10.1061/(ASCE)EM.1943-7889.0000465

• Nonlinear analysis
• Pavement response
• Cross anisotropic
• Viscoelastic asphalt layer
• Granular base modulus
• Moving load
• Finite-element model

This 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 support) but also by temperature and vehicle speed because of the viscoelastic behavior of the asphalt surface layer. Excluding the cross-anisotropic stress-dependent behavior of the granular base layer could cause significant error in predicting fatigue cracking and rutting potential in thin asphalt pavements. In addition, the model results captured the trends of field measurements at different loading and temperature conditions. DOI: 10.1061/(ASCE)EM.1943-7889.0000465.

• 出版日期2013-1