Risk assessment of ANAS tunnel stock in the north-east of Italy and the case study of the SHM of Comelico tunnel

Abstract

The management of tunnel safety is a crucial element for the protection of road infrastructure, user safety, and the preservation of structural durability. In this context, the framework agreement between the National Autonomous Roads Corporation (ANAS) and BOLINA Engineering plays a significant role, focusing efforts on the road network in Northeast Italy and adopting advanced practices in compliance with current regulations to ensure the safety of numerous tunnels within the ANAS network. The recent Guidelines for Tunnels (Ministerial Decree number 247 of August 1, 2022: Approval of Guidelines for classification and risk management, safety assessment, and monitoring of existing tunnels along state roads or highways managed by Anas S.p.A. or highway concessionaires) constitute a robust regulatory framework for tunnel safety management, proposing a tailored, layered approach based on the criticality of individual structures. In this context, BOLINA Engineering, as a strategic partner of ANAS, actively engages in engineering activities aimed at assessing tunnel safety.Within the scope of the received mandate, BOLINA operates by focusing on the determination of the Attention Class, a crucial phase for tunnel safety management. This process involves various stages:Information Collection: Involves acquiring all design data and documenting structural characteristics through the completion of an identification form for each tunnel.Direct Visual Inspections and Surveys: Include direct visual investigations and rapid surveys of the structure, along with the analysis of geomorphological and hydraulic features. This phase aims to identify existing degradation, geometric and structural properties, and potential associated risks.Risk Parameter Assessment: Based on the assessment of hazard, exposure, and vulnerability parameters derived from previous investigations. This phase assigns an Attention Class to each tunnel (High, Medium-High, Medium-Low, Low), determining subsequent actions needed to ensure structural safety.The goal of this synergy between ANAS and BOLINA is to ensure the safety and durability of structures, with particular attention to the needs of the road network in Northeast Italy. The aim is to achieve an exemplary infrastructure management model by integrating the best engineering practices with regulatory provisions, ensuring user safety and the long-term preservation of road structure integrity. Subsequently, an overview of ongoing activities will be presented, followed by the presentation of a specific case representing the work conducted on each tunnel within the examined asset.