Flexible Pavement Response Analysis under Dynamic Loading at Different Vehicle Speeds and Pavement Surface Roughness Conditions

Abstract

Pavement responses are affected by the magnitude and frequency of dynamic loads generated by vehicles, which are significantly dependent on axle configuration, pavement surface roughness, and vehicle speed. This paper analyzed the dynamic loading effect on flexible pavement responses at different vehicle speeds and pavement roughness conditions using an integrated vehicle–tire–pavement interaction approach. Full truck models were used to estimate vertical tire forces caused by pavement profiles with different roughness levels. An advanced three-dimensional (3D) finite element (FE) model was utilized to simulate pavement responses under dynamic loads with nonuniform tire contact stresses. The dynamic load coefficient (DLC) of tire forces increased linearly with vehicle speed for Class 5 vehicles considered in the analysis. This increasing trend was found more significant for the rougher pavement surface. The analysis results indicated that the rougher pavement surface could cause greater pavement responses and accelerate pavement failure at the locations where high dynamic loads were induced. In general, a higher speed would cause smaller strain responses in asphalt pavements. However, the decrease of pavement responses with the increase of speed became less obvious considering the influence of dynamic loads. The study results provided the upper and lower limits of pavement responses due to dynamic loads for mechanistic-empirical pavement design applications.