PSI - Issue 62

Carla Assunta Trifarò et al. / Procedia Structural Integrity 62 (2024) 57–64 C.A. Trifarò et al./ Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 2. (a) Structural/foundational and (b) seismic attention classes

Generally, the results (provided by the handling body ANAS S.p.A.) highlight that almost 80% and 90% of the structures are characterized by an attention class higher than or equal to medium-high with reference to the structural/foundational and seismic risks, respectively. Such results can be certainly related to the significant exposure of the highway network under investigation, the significant seismic hazard affecting the Appenine area, as well as the defectiveness level representative of the conservation state of the structures. 3. Statistical analysis of the defectiveness 3.1. In-situ inspections The data referred to the defectiveness levels of the structures were acquired by the handling body. ANSFISA was called within these activities to check the reliability of these data. This was done by randomly inspecting the structures under investigation. In almost all cases, the in-situ inspections performed by ANSFISA confirmed the state of conservation of the structures previously determined by the survey of the defectiveness level according to the Italian Guideline procedure. Generally, the most significant structural issues detected on the structures were due to defective and obsolete systems of rainwater conveying. This appeared significantly important for simply supported structures since the water is able to percolate through the deck joints and flow along pier surfaces. Therefore, many substructure elements showed moisture traces, wet concrete surfaces, and, in the worst cases, exposed and corroded steel bars. The collected and retrieved data were elaborated in order to obtain a measure as objectively as possible of the defect level of the structures, as well as of the single structural elements. Thus, for each structural element i , the relative defect index D r,i was estimated according to Eq. (1).

, r i j D G k k =    1, j j

(1)

2,

j

In the equation, the relative defect index D r,i reads as the sum of the importance ( G ), extension ( k 1 ) and intensity ( k 2 ) of each observed defect j . It is worth mentioning that the importance of the defect G is a-priori defined according to the Italian Guidelines, while extension and intensity were assessed during the in-situ inspections. Based on such an evaluation, it is possible to define a total relative defect index for each structure D r as per Eq. (2).



D

, r i



D

=

i

(2)

r

n

k

i