Specifically, the goal of SHM is to improve safety and reliability of infrastructure systems by detecting damage before it reaches a critical state and allow rapid post-event assessment.
Accordingly, through the analysis of the data provided by a SHM system it is possible to gain the advantages of early identification of structural anomalies that, due to their extremely slow evolution, are hardly detectable with other investigation techniques, such as inspections or non-destructive assessment campaigns, and becomes evident only at a very advanced stage of the degenerative process.
SHM system not only allows to detect structural anomalies before they can evolve to complex damage situations, but it also provides data useful to identify the primary causes of the degenerative processes, thus allowing wiser and more durable conservation interventions done by removing the causes of the anomalies rather than by retrofitting the damaged members.
In addition to the improvement in damage detection, SHM is to provide in time a deeper and more detailed knowledge of the structural behavior of the building under investigation, thus adding reliability to the estimations regarding its residual life and resistance to calamities and allowing a wiser optimization of the maintenance schedule.
Considering the typology of the application it stands clear that the primary requirement of a SHM system are related to the possibility of granting a capillary presence on all the location of the structural members of interest but being minimally invasive and easily to hidden both for aesthetic and conservative reasons. In addition, a scalable system approach is to be preferred, especially considering the extension of the building, the complexity of the structural behavior to be monitored and the possible evolutions of the monitoring needs.
Accordingly, the SHM systems usually installed and managed by EXPERIMENTATIONS (see SMARTBRICK®) is equipped with embedded sensors and battery supply and features direct internet connection through GSM/3G network in order to make the collected data immediately available on a remote server and displayed on a protect web-application.
The whole SHM service provided by SGM includes:
Many different kind of measuring devices can be connected to the SHM system based on the structural parameters of interest, some of them are summarized hereafter:
Additional and specific SHM systems are also available for civil infrastructures where the dimensional scale has to be taken into account in the design of the SHM system. One of the most common and advanced system is the represented by the ground-based Interferometric Radar which allows the remote monitoring of movements of large portions of territory (landslides, slopes, volcanoes, glaciers etc.) and of structures (dams, bridges, towers, tunnels, buildings etc.) with sub-millimeter accuracy. The device allows to generate, transmit and receive electromagnetic signals and determine the time required by a radar signal to reach the target and return to the device and it also elaborates information regarding resonance frequencies and modal forms.