Proposal and Verification of Countermeasures against Fatigue Cracking from Weld Joints between Trough Ribs and Cross Ribs in Orthotropic Steel Decks

Abstract

Orthotropic steel decks (OSDs) have a problem on fatigue durability, while OSDs have advantages of light weight and short construction time. The effective countermeasure against fatigue cracking at welded joints between a deck plate and trough ribs have been already proposed. In this study, focusing on fatigue cracking at welded joints between trough ribs and cross ribs, countermeasures for existing structures and renewal and newly established structures are proposed, and verified through fatigue tests using a large specimen with similar scale as actual OSD structures. Principal results obtained through this study are as follows. By retrofit using TRS and angles for the existing structure, the sufficient effect of preventive countermeasure and post countermeasure against fatigue cracking at welded joints between trough ribs and cross ribs has been verified through fatigue tests. However, fatigue cracking at welded joints between a deck plate and trough ribs could not be prevented. In the new structure, any cracks have not been initiated from the connection between a trough rib and a cross rib, and a deck plate. The sufficient fatigue durability was confirmed.