Fatigue Design of Steel Bridges Considering the Effect of Dynamic Vehicle Loading and Overloaded Trucks

Abstract

AbstractThe current practice for bridge-fatigue design may have underestimated the effect of dynamic vehicle loading and truck overloading on the fatigue life of steel bridges. In this study, a new approach for fatigue design of steel bridges was proposed that considers the effect of these two factors more rationally. A three-dimensional vehicle–bridge coupled model was developed to simulate the interaction between the bridge and vehicle. A simply supported steel I-girder bridge was used as an example for illustration of the proposed approach. The fatigue vehicle model was adopted from the AASHTO LRFD code, and overloading was considered by increasing the gross weight of the truck model. Numerical simulations were conducted to study the influence of three important parameters—road surface condition (RSC), vehicle speed, and truck gross weight—on the fatigue damage of the bridge considered. The results show that the RSC and truck gross weight both have a significant impact on the bridge-fatigue damage. By ...