Inelastic behavior of orthotropic steel deck stiffened by U-shaped stiffeners

Owing to its high strength and stiffness, the orthotropic steel deck system has been widely used in the construction of long-span steel bridges. However, due to esthetic and economic considerations, slender types of orthotropic bridge have become very popular in recent years. Consequently, the stability of the orthotropic steel deck system under traffic load becomes more critical. Although the instability problem of the orthotropic steel deck system due to flexural compressive stress has been recognized for years, current bridge design specifications do not clearly specify the criteria to prevent local buckling of the orthotropic deck system. Most previous studies on orthotropic steel deck systems were focused on the out-of-plane behavior of the steel deck, and limited study has been carried out on the in-plane compressive behavior of the orthotropic steel deck system. There is a lack of knowledge on the inelastic behavior of the orthotropic steel deck system under flexural compressive stress. In this study, the inelastic behavior of 30 full-scale orthotropic steel deck specimens was examined. According to this study, it is found that the current design practice may lead to local buckling of the deck system. Based on this study, criteria are proposed for the requirement of compact and non-compact sections. Design guidelines for the inelastic ultimate strength of the steel deck system are also suggested.