FATIGUE DURABILITY OF COUNTERMEASURES FOR U-RIB TO DECK WELDED JOINTS FROM UNDERSIDE OF EXISTING ORTHOTROPIC STEEL DECKS

Abstract

 A countermeasure method is proposed for fatigue cracks that initiate from the weld root of U-rib to deck welded joints of orthotropic steel decks, which does not require traffic restrictions and does not increase the dead load. On the other hand, fatigue durability of general parts except for cross rib sections and ranges of peening treatment are still unclear. This paper attempts to solve those problems and verifies the durability of the fatigue countermeasure method. First, fatigue test methods that can reproduce fatigue cracks in the general parts of U-rib to deck welded joints of existing orthotropic steel decks was investigated. Next, based on the investigation results of fatigue test methods, the fatigue durability of general parts of the countermeasure was clarified by wheel running test, and the data necessary for determining the peening treatment areas were obtained. Finally, a proposal for improved countermeasures is presented.