Effective structural health monitoring (SHM) system for bridges: A case study

In the last few years, an increasing amount of resources have been invested in the maintenance of existing infrastructure systems in Italy because of the recent catastrophic collapses of structures. In fact, it is now clear that bridges require proper management by the administering entities, which foresee a detailed control of the health condition of the structure over time, as well as the execution of the required works for good maintenance. Therefore, the assessment of the structural "health"state of such systems has a crucial role. The monitoring of vibration modes has proved to be an excellent tool for SHM systems since they are related to intrinsic properties of the structure (i.e., mass, stiffness, and damping) and, therefore, to possible damage on the structure. In a much broader perspective, not only the monitoring of "old"infrastructures is considered but also of new construction so as to have data traceable to healthy structures that serve as a basis for comparison in the examination of the development of damage. Therefore, in the present work the layout of the SHM system with the innovative sensors of a recently built steel bridge was designed. A preliminary numerical model based on the information from the design documents has been developed and used for the application of OSP (optimal sensor placement) techniques to identify the optimal positions of the sensors to be used for a future SHM system.