PSI - Issue 62

Luigi Petti et al. / Procedia Structural Integrity 62 (2024) 16–23 6 Petti L, Montuori R, Lupo C, De Gaetano CM, Guida D, Loncarevic D and Repetto E/ Structural Integrity Procedia 00 (2019) 000 – 000

21

Fig. 4. Bridge’s single element ID code.

4. Results and Preliminary Considerations The surveillance activities of the A3 highway involved the application of two monitoring methodologies, the first one defined by LG20 and another one (the ordinary method) adopted for ordinary inspections, used before the release of the guidelines LG20. The adopted methodology for the ordinary inspections leads to evaluating the bridge priority index. Such an index considers a degradation score, assigned to each type of defect in the range of 10 (the defect will not evolve into another defect) to 70 (immediate interventions), the defect extension (punctual DP – widespread DD), and the evolution rate (slow EL – fast ER). The bridge priority indices (low priority A – high priority E) are evaluated in the following matrix (Table 2). Table 2. Priority indexes matrix, according to CUGRI methodology. E In particular, the CUGRI methodology for ordinary inspections takes into account the degradation score defined in the guideline adopted by ASPI (Italian Highway Main Management Corporation) in 2015 [ASPI (2015)] and a qualified assessment of the local and overall safety conditions. The priority indices matrix has been instead elaborated by CUGRI taking into account the available historical inspection data. Figure 5 shows the results in terms of Defectiveness Level, according to the results of LG20 Level 1, and the Degradation Score, derived from the ordinary inspection method. Both approaches produce consistent results concerning the higher defect level, in particular 16% for LG20 methods and 14% through ordinary inspections. Instead, it is possible to note a great difference between the lower levels. The LG20 leads to 80% of bridges characterized by medium defectiveness level, while, only 33% of the bridges have a medium degradation score in the case of ordinary inspection. EXTENT SCORE 40-43 50 60 EL ER EL ER EL ER DP DD A B B C C D D E D E E

Fig. 5. Defectiveness Level and Degradation Score obtained respectively from LG20 and ordinary inspection approaches.

Figure 6 describes the outcomes of the LG20 approach in terms of Structural and Foundational CdA and Overall CdA. The results highlight the strong influence of Structural and Foundational CdA on the higher values of the Overall CdA, having approximately the same percentage of bridges (38% and 39% respectively), while the lower ones are different, due to the impact of local hazard conditions. The approach to assess the CdAs of Level 2 has been completed