Influence of roughness and cross slope induced dynamic loads on flexible pavement responses

Among all the factors influencing flexible pavement design, vehicular loads are of prime importance. Thus the present study evaluates the dynamic wheel loads on the pavement by considering the prime factors related to the vehicle and the pavement. Relationships are developed for three different trucks considering the combined effects of vehicle speed, gross vehicle weight, and pavement roughness on dynamic loads. The study further quantified the effect of pavement cross slope on vehicular loading in the outer wheel path. Furthermore, the critical responses for a flexible pavement section are determined using finite element analysis by considering the viscoelastic properties of asphalt layers and moving loads. The findings of this study reveal that, even for a smooth pavement with roughness ranging between 1 and 2 m/km, the dynamic load can be 7-13% higher than the static weight. The dynamic loads further increase rapidly as the pavement deteriorates. Compared to the conventional static analysis, incorporating dynamic loads into pavement analysis revealed an increase in the critical responses by 6-50%. Further, due to the interplay between vehicle speed, dynamic load coefficient, effective load, dynamic modulus, and loading frequency, a non-linear decrease in critical responses is observed with increased vehicle speed.

Automated summary

This study evaluates dynamic wheel loads on the pavement by considering prime factors related to the vehicle and the pavement. Relationships for three different trucks are developed, considering the combined effects of vehicle speed, gross vehicle weight, and pavement roughness on dynamic loads. The effect of pavement cross slope on vehicular loading in the outer wheel path is also quantified. Additionally, incorporating dynamic loads into pavement analysis reveals an increase in critical responses compared to conventional static analysis, with a non-linear decrease observed with increased vehicle speed.