Finite element modeling of the impact of heavy vehicles on highway and pedestrian bridge decks

Collisions of over-height vehicles, such as tipper trucks or exceptional convoys, with highway and pedestrian bridge decks can compromise the safety of road users and cause major economic losses due to road closures required by structural inspections and urgent repairs. Several studies proposed to reduce the probability of occurrence of such events by using steel pedestals, static road signs or impact detection systems. In spite of these preventive solutions, bridge decks are still frequently impacted by heavy vehicles as a result of the densification of transportation networks. In this study, a practical finite element approach is proposed to investigate the key parameters influencing the dynamic response of a bridge deck subjected to an impact from an excavator or other heavy construction equipment trailed on a flatbed truck. The developed finite element models are used to carry out a parametric study on vehicle-bridge systems with varying properties such as the lateral stiffness and mass of the bridge deck, and the mass and the velocity of the colliding vehicle. It is first shown that contact compliance is a critical factor that should be selected carefully after several numerical tests supported by engineering judgment. The obtained results confirm that dynamic effects are key factors to be taken into account when studying vehicle-bridge collisions. The trends characterizing the collisions between a heavy vehicle and the bridge deck are studied in terms of contact forces and their duration, the structural response of the bridge deck, as well as kinetic energy of the impacting vehicle. Some of the results obtained are compared to analytical predictions proposed in Eurocode.

Mots clés

Collision; Impact; Dynamic Loads; Bridge Decks; Finite Elements; Eurocode; Compliance; Heavy Vehicle; Contact