Framework of wind-traffic-bridge coupled analysis considering realistic traffic behavior and vehicle inertia force

The performance of a long-span bridge under strong wind and traffic loads is of great importance to ensure the functionally and the serviceability of the bridge as well as the safety of running vehicles. In this paper, an innovative wind-traffic-bridge (WTB) interaction model for predicting the dynamic performance of the long-span bridge and running vehicles under the crosswind is proposed, considering realistic traffic behavior and vehicle inertia force. In this regard, the LAI-E traffic simulation model aiming to faithfully reproduce realistic traffic flow is developed by integrating the kinetics theory, vehicle capabilities, and driver reactions. The results indicate that using the traditional NaSch traffic model results in a significant overestimation of the vehicle lateral response under a windy environment, whereas the LAI-E traffic model can overcome this issue by ensuring a smooth speed transition during the vehicular acceleration/deceleration process. Additionally, when the vehicle accelerates or decelerates at the emergency capability, the additional pitching moment caused by the vehicle inertia force can result in remarkable increase of vertical wheel contact forces. The present study suggests the necessity of considering both realistic traffic behavior and vehicle inertia force during the WTB analysis.