Issues in SHM of existing bridges: From periodic checks to continuous structural health and performance assessment

Operational and structural safety of road and highway networks is a key problem in many countries, where the existing infrastructures are in service from many decades and they are close to the end of their lifespan. This is the case of many European countries, where a strong effort in the development of transportation networks was made in the early decades after the Second World War. A variety of structures have been built according to the knowledge at the time of design and erection and, in some cases, disregarding environmental actions like the earthquakes. As a consequence, there is an urgent need for rational and effective approaches to the remote structural health assessment of bridges. In the present paper, after an overview of relevant issues in structural maintenance and safety assessment of existing bridges, relevant research findings from structural monitoring of bridges are reviewed to remark potential and drawbacks of continuous Structural Health Monitoring (SHM) for effective health and performance evaluation.