ABSTRACT
Due to their lightness and cost effectiveness, orthotropic steel deck bridges are one of the most popular alternatives for bridges constructed in urban and metropolitan areas in Japan. However, fatigue is still a serious problem when considering durability in orthotropic decks. The present study focuses on the connection between trough ribs and crossbeams, particularly the welded joints around the slot at the bottom of trough ribs, where a great number of the fatigue cracks has been reported. A new fatigue retrofit method using TRS (Thread Rolling Screw), which secures the watertightness of trough ribs, was proposed for the connection between trough ribs and crossbeams in orthotropic steel decks and executed in a bridge in service. Dynamic loading tests and stress measurements under service load were performed in situ, before and after the execution of the retrofitting works to verify the effectiveness of the new retrofit method.
