In this study, tireûpavement interaction was analyzed using measured three-dimensional (3-D) tire contact stresses at various load levels (35, 44, and 53kN) and constant tire pressure (720 kPa). The combined effect of moving wheel load and 3-D contact stresses on flexible pavement response was evaluated using a developed 3-D finite element (FE) model. This model incorporates the measured 3-D tire contact stresses, hot-mix asphalt (HMA) viscoelasticity, and continuous moving load using implicit dynamic analysis. In the FE modeling, a perpetual pavement design with 254-mm HMA placed on 305-mm lime-modified subgrade was exposed to dual tire loading. The critical pavement responses under two loading conditions (uniform contact stresses and measured 3-D contact stresses) at various load levels were calculated and compared. It was found that the 3-D tire contact stresses induce greater pavement stresses and strains at pavement near-surface (shear strains and octahedral shear stresses) and at deeper depths (transverse tensile strains and compressive strains), comparable to the uniform contact stresses. This suggests that using uniform contact stresses could underestimate pavement damage, especially ônear-surfaceö cracking potential and shear flow in perpetual pavement. The transverse tangential stresses induce the outward shear flow from the tire center and shear strain concentration at pavement near-surface. Increasing the wheel load mostly increases the contact stresses at the tire edge and the corresponding shear strains and octahedral shear stresses. The difference between the pavement responses caused by the uniform contact stresses and 3-D contact stresses decreases when the wheel load increases.
Samenvatting