A strategy for rib-to-deck crack propagation analysis and strengthening of orthotropic deck bridges

•Crack initiation analysis confirms that a rib-to-deck welding connection is a critical zone•Crack propagation analysis using XFEM confirms the influence of the transversal tension on the crack propagation direction•Crack propagation analysis using XFEM verifies the usefulness of two proposed repair actions Rib-to-deck connections are one of the most critical fatigue-prone locations in orthotropic steel decks. Initiated cracks in the root of a fillet weld in this location can propagate towards the deck plate due to the existence of transversal tension within the deck plate near the cracking area. Such cracks can put the structure in a very critical situation since they can reach their critical length without being inspected. The main goal of this paper, therefore, is to investigate the influence of the transversal tension on the crack propagation direction in this region. For that, one translates the loading and boundary conditions from a 3D model to a 2D model to avoid computational issues with 3D modelling. Then, a 2D crack propagation analysis is performed using XFEM method, enabling the comparison of several repair solutions. To illustrate the proposed concepts, this paper investigates the fatigue problem on a real bridge case study and characterizes the effectiveness of two possible repair solutions to cope with such fatigue issues.