Problems in the inspection of old metal bridges

Abstract

One of the main objectives in the inspection of old metal bridges is to identify the risk of brittle crack failures. There are many factors involved in this problem: the usual low toughness in old metal structures, the increased loads supported by the old bridges (permanent and also live loads); the possibility of fatigue fissures appearing, taking into account that their connection details were designed when this problem was unknown; development of corrosion, which could weaken sections, create tensile concentrations, etc. Some bridges with those problems are then analysed. Finally, from this analysis, some complementary actions are proposed that would lead to a better risk assessment of these bridge structures without a great increase in costs.