A METHOD TO SELECT LARGE SCALE REPAIR SECTIONS OF EXPRESSWAY VIADUCTS BASED ON INITIATION AND PROPAGATION PROCESSES OF FATIGUE CRACKS ON STEEL SLABS

Abstract

 Initiation and propagation of a large number of fatigue cracks on a steel slab of an expressway viaduct would reduce its fatigue durability considerably. For such failures and damages which cannot be repaired radically with usual repair methods, it is necessary to establish management plans considering large scale repair methods based on the initiation status and the propagation process of failures and damages. In this study, a method is proposed to estimate initiation and propagation processes of fatigue cracks on steel slabs with high accuracy, considering initiation timings, which cannot be directly observed by visual inspections, as latent variables. Then a methodology is proposed to select between normal repair and large scale repair for each repair unit based on life cycle costs calculated with the estimated initiation and propagation processes of fatigue cracks. Lastly, the proposed methodology is demonstrated with actual steel slabs of expressway viaducts.