MAINTENANSE AND MANAGEMENT FOR FATIGUE DAMAGE AT THE CONNECTIONS MAIN GIRDERS AND CROSSBEAMS OF HALF-THOUGH PLATE GIRDER

Abstract

 At the JR EAST, close visual inspections are conducted using scaffolding during repainting to capture subtle damages, such as fatigue cracks. During a close visual inspection of a half-through plate girder bridge, fatigue damage was confirmed at the flange welds of the main girder. Fatigue damage to the main girder is a serious defect that could lead to bridge collapse and pose a threat to the normal operation of trains, making it crucial to prevent similar defects in advance. In this initiative, the causes of the fatigue damage were estimated, and structural characteristics prone to similar damage were identified to survey similar bridges. Repairs were performed for the confirmed fatigue damage, and reinforcement structures were proposed to prevent similar defects.