Reinforcement and Treatment of Fatigue Cracking in Orthotropic Steel Bridge Decks: A Review

Fatigue cracking significantly affects the service performance of orthotropic steel bridge deck (OSD), making their reinforcement and treatment the focus of intense research in recent years. This paper analyzes and summarizes the development of fatigue cracking reinforcement for OSDs, focusing on key issues and future development directions. The results indicate that multiple fatigue cracking modes of the welded joints are the fundamental attributes of fatigue problems in OSDs. The applicability and effectiveness of reinforcement methods are closely related to the fatigue cracking mode and the fatigue crack length. Taking assembly reinforcement as an example, a new synergistic structure system is developed by incorporating reinforced components in existing structures. Local stress characteristics of the fatigue cracking area in the synergistic structure system is changed notably in contrast with the existing structure, thereby achieving performance enhancement and longevity. The reinforcement system contains existing fatigue cracks, cumulative fatigue damage in uncracked modes, and parts vulnerable to new fatigue generated by reinforcement. The fatigue cracking modes of the reinforcement system are diverse and complicated. Key issues such as the damage status of each cracking mode before reinforcement, the stress state of the reinforcement system, the cracking mode of the reinforcement system, and the prediction of its remaining lifetime are important foundations for studying OSD reinforcement and treatment. The assessment of the actual damage status and damage reconstruction methods for in-service OSDs, the remaining lifetime prediction of the synergistic structure system, as well as the reinforcement design based on the remaining lifetime of the reinforcement system are issues of considerable interest for fatigue cracking reinforcement in OSDs. The reinforcement method based on new materials and the treatment methods applicable to OSDs with significant fatigue cracking are important research topics that require urgent attention. © 2024 Chang'an University. All rights reserved.