PSI - Issue 44

Giuseppe Iiritano et al. / Procedia Structural Integrity 44 (2023) 641–648 Giuseppe Iiritano et al./ Structural Integrity Procedia 00 (2022) 000–000

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1. INTRODUCTION The “Linee Guida per la classificazione e gestione del rischio, la valutazione della sicurezza ed il monitoraggio dei ponti e viadotti esistenti”, approved by “Consiglio Superiore dei Lavori Pubblici” and adopted by “Ministero delle Infrastrutture e dei Trasporti” (now “MIMS”) with DM 578 of 17/12/2020, introduced a multi-level approach to solving the problem of managing existing bridges and viaducts. The difficulties in carrying out in-depth and accurate checks on all the bridges and viaducts present on the national territory, given the large number of them, have made it necessary to develop a tool that could allow to increase knowledge on all the works in the territory and at the same time to define, in a simple and rapid way, an order of priority for the execution of more in-depth analyzes. The multi-level approach was therefore born with this purpose, allowing to move from expeditious assessments, applicable on a territorial scale, to more in-depth assessments, on a limited number of bridges selected on the basis of the results of expeditious assessments. Level "0" of this approach consists in the census of all the bridges and viaducts in the area in order to know the number of structures to be managed and their main characteristics, both in relation to geometry and structural elements, and in relation to the road network in which are inserted and to the site where they are located. Level "1", extended to the works surveyed at level 0, provides for the execution of direct visual inspections and the expeditious survey of the structure and of the geo-morphological and hydraulic characteristics of the area, aimed at identifying the state of decay and the main structural and geometric characteristics of all the works, as well as potential risk conditions associated with landslide events or hydrodynamic actions. Level "2" allows to reach the attention class of each bridge, based on the parameters of hazard, vulnerability and exposure, determined by processing the results obtained from the previous levels. According to this classification, we then proceed with one of the following levels. Level "3" provides for the execution of preliminary assessments designed to understand, together with the analysis of the type and extent of the failures detected in the inspections carried out at Level 1, whether it is in any case necessary to carry out further investigations by performing accurate checks of Level "4". Level "4" provides for the execution of accurate assessments on the basis of what is indicated by the “Norme Tecniche per le Costruzioni” in force. Level "5", not explicitly dealt with in the “Linee Guida”, applies to bridges considered to be of significant importance within the road network, appropriately identified. For these works it is useful to carry out more sophisticated analyzes such as those of resilience of the branch of the road network and / or of the transport system of which it is a part, evaluating the transport relevance, analyzing the interaction between the structure and the road network to which it belongs. and the consequences of a possible interruption of the operation of the bridge on the socio-economic context in which it is inserted. With the Deliberation of the Regional Council n. 207 of 13.07.2020, the Calabria Region has given direction to the Department "Infrastructures, Public Works, Mobility" for the definition of the implementation program defined "Operational plan for monitoring bridges and viaducts of not ANAS road networks". With the same DGR 207/2020, 5 million euros were allocated for the launch of a knowledge program on the current state of the bridges and viaducts of the Calabrian secondary road network with the aim of achieving the achievement of level "0" for all bridges and viaducts of the secondary road network and level "2" for a good percentage of the bridges and viaducts managed by the provinces and the metropolitan city of Reggio Calabria. 2. CENSUS: WHAT HAS BEEN DONE In September 2020, the Calabria Region started the census phase (level "0") of all the bridges and viaducts managed by the Provinces and the Metropolitan City of Reggio Calabria.