Issue 46

F. Bazzucchi et alii, Frattura ed Integrità Strutturale, 46 (2018) 400-421; DOI: 10.3221/IGF-ESIS.46.37 414 clinics without a general diagnostician that performs a fast screening with limited number of symptoms. But the numbers discussed earlier and the projections for the needs of infrastructures of the future urban population [31]: the need for doctors and diagnosticians of the complex infrastructures organisms is imperative and high-priority. To fulfill this objective, we need techniques and technologies that allow us to see inside the structures, to interpret symptoms with a scalable procedure, and to protect the artifacts. Figure 19 : Steel resurfacing for I-beams of an overpass [Copyright: RELUIS]. Figure 20 : X-Ray device (a) [Copyright: https://www.novo-dr.com/ ]; scanned image (b) of specimen (c) ; scanned image (d) of specimen (e) . X-ray inspections As has been said, referring the state of a SHM system to a quantitative degree is not possible in the majority of cases. Moreover, precast structures suffer from an intrinsic fragility due to the technology itself. The decay of structural properties is difficult to detect until the ultimate steps of the load capacity curve [5]. To a reduction in cable section, corresponds an increase of stress in the effective area without any significant decrease in global properties. Otherwise, the area reductions observed in the previously illustrated cases were considerable. The collapse of Fossano bridge must have been occurred with a local reduction, in the total cables section, of at least 35% of the initial one. This means that, a