Fatigue durability of large‐sized trough rib ortho‐tropic steel deck for deck crack

A lot of fatigue cracks were reported in orthotropic steel deck (OSD) because the structure of OSD supported wheel load directly. Among them, many fatigue cracks at the intersections between trough rib and transverse rib were reported. Improved structures of the the intersections between trough rib and transverse rib were reported by many researchers. The purpose of this paper is to propose new structure of OSD that using Thread Rolling Screw at joint of trough rib and transverse rib instead of welding and confirming its fatigue durability by fatigue test. Two specimens were prepared. These differences are thickness of deck plate. After fatigue test, we drilled 40 mm diameter hole at upper deck surface and conducted magnetic particle testing to confirm development of deck crack. As a result, fatigue cracks developed at the connection between transverse rib and deck plate in existing structure while no fatigue cracks were detected in proposed structure.