Instrumented infrastructures for damage detection and management

The Authorities that are responsible for the design and management of infrastructures have an increasing need of information and support in order to optimize their work, save money, time, and, sometimes (e.g., in case of disastrous events), lives. Technological development is leading to new possibilities, in terms of new technologies increasingly available, widespread, reliable and inexpensive and that can be applied to make smart cities safer and more efficient. Hence, new methods and devices may be thought out in order to respond to these requests and to help Authorities during the structural health assessment/monitoring (SHA/SHM) of infrastructures and also during the emergency management. To this end, in this paper a new SMA/SHM method is proposed and validated through experimental investigations. The new proposed method is based on the vibro-acoustic response of a transportation infrastructure and pertains to its SHA/SHM. The method builds on using the road traffic noise as source of vibrations and sounds. Microphones are placed in different positions (in drilled holes and/or on the upper surface: receiver), and vibro-acoustic signals are recorded. The spectra of these signals are expected to represent the vibro-acoustic signature of the road pavement under investigation. From the analysis of this signature, information about the presence and the severity of cracks into the layers of the road section can be derived. In the pursuit of the method validation, non-destructive on-site tests, aimed at classifying the level of damage through high-speed devices/methods (i.e., visual detection of surface distress, moduli estimation through the light falling weight deflectometer (LWD), laser detection of roughness), were carried out. Road pavements in different structural conditions were investigated. From the analysis of the gathered acoustic signatures, the identification and localization of cracks into the pavements under investigation was carried out. These results are going to be used to set up a preliminary database of acoustic signature of different road pavements. Further applications of the new method are expected for a large number of road infrastructures, aiming at enriching the abovementioned database and improving predictive algorithms. Based on the proposed method, it is expected: i) to make available an estimation of the level of integrity of a road pavement to use in the management of transportation infrastructure for better, safer, and more economical smart cities and roads; ii) to provide a fast, inexpensive, and useful tool for the authorities that are responsible for the management of road infrastructures and other civil infrastructures in smart cities; iii) to provide a tool for delivering essential services to citizens.