PSI - Issue 62

Stefano Grimaz et al. / Procedia Structural Integrity 62 (2024) 161–168 S. Grimaz et al./ Structural Integrity Procedia 00 (2019) 000 – 000

162

2

1. Introduction According to Italian law (D.L.109, 28/09/2018, art.12), the Italian National Agency for Railway and Road Infrastructure Safety (ANSFISA) holds primary responsibility for safety oversight of the national railway system, roadways, and highways. This oversight occurs through annual activity programs wherein ANSFISA conducts scheduled inspections to monitor infrastructure maintenance activities performed by managing entities accountable for safe operations. Additionally, ANSFISA may conduct inspections to identify safety risks and compel managing entities to implement necessary measures for risk control and safety interventions. As a supervisory authority over diverse assets and entities, ANSFISA requires comparative and detailed safety assessment tools for railway and road infrastructures. Addressing these requirements, ANSFISA activated a specific collaboration with the Safety and Protection Intersectoral Laboratory (SPRINT-Lab) of the University of Udine (Italy) , launching the “Safety Inspection Visits of Road Infrastructures” (VISIVIA) project for surveillance purpos es (Grimaz et al., 2023). The VISIVIA project aims to develop a tailored visual inspection methodology for on- site surveillance (termed “Visual Inspection for Safety- deficit Identification and Triage”, VISIT). It also intends to design a prototype dashboard for ANSFISA monitoring and planning activities, alongside a prototype IT tool to test the VISIT methodology. This prototype will serve as a reference for subsequently developing a final product for ANSFISA activities. The VISIT methodology is based on an analogy with the medical sector and considers the different assets to investigate “ as patients ” in a triage decision-making process of evaluation for treatment. The inspected infrastructures are analyzed by segments and with reference to different assets in each segment, i.e., roads, bridges, and tunnels. Every asset has a tailored assessment procedure to ensure uniform judgment criteria using standardized evaluation for consistent inspection by various inspectors. VISIT employs an analysis approach utilizing predefined semeiotic parameters that are systematically analyzed and assessed by ANSFISA inspectors assigning a warning level via pre coded procedures, to generate a situational chart. In VISIT, the semeiotic parameters are the elements or characteristics that inspector takes into consideration for assessing the condition of an asset. A more detailed overview of the VISIVIA project and VISIT methodology can be found in Grimaz et al. (2023). This paper focuses on the application of VISIT to bridges. It outlines the identified semeiotic parameters and assessment procedures for bridges; then it discusses the use of drones for on-site inspections, and presents results from comparing various inspection strategies across multiple bridges along the SS13 “Pontebbana” , a road in Italy. 2. VISIT methodology applied to bridges The Italian Government has recently adopted the “Guidelines for the risk Management of Existing Bridges” (Cutrone, 2023), referred to as “Italian Bridge Guidelines” . These guidelines aim to provide road managers with a standardized procedure based on a uniform classification system, enabling also a consistent approach to the maintenance of existing bridges. The procedure is based on six levels, with the first three applied universally to all bridges, and the next three reserved for those with higher priority, due to elevated “Structural/Operational”, “Seismic”, “Landslide” and /or “Flood” risks. The procedure involves a multi-risk analysis to assess the “Overall Attention Classification” for each element that constitutes the bridge “domain”, in order to manage the safety and the maintenance of the domain. In particular as outlined by Buratti et al. (2022) and Santarsiero et al. (2021), the first two levels of the guidelines (i.e., Level 0, focusing on the main bridge characteristics, and Level 1, involving visual inspections to explore the actual conditions, including defects on structural elements) aim to identify the parameters, whether primary or secondary depending on their importance. These parameters are consequently used to define the levels of risks and the priority ratings. Worldwide, the conditions of bridges are often evaluated through visual inspections, to define the optimal maintenance strategy that minimizes the cost of interventions over time (Hearn, 2007; Puž et al. ,2012 ; Mirzaei & Adey, 2015; Quirk et al., 2017; Bertola & Brühwiler, 2021). The development of the VISIT methodology for bridges heavily relied on the Italian Bridge Guidelines to ensure alignment with Italian regulations and the management approach of relevant entities (the VISIT-bridges methodology could be collocated as a Level 1 approach according to the Italian Bridge Guidelines). However, it ’ s important to note that the VISIT methodology is primarily intended for visual inspections for ANSFISA surveillance purposes and not