PSI - Issue 84

Enrico Mittiga et al. / Procedia Structural Integrity 84 (2026) 867–873

868

Keywords: tunnel renovation; lining; precast elements; traffic disruption.

1. Italian Territory and Anas Network The Italian territory presents significant geological variety associated with great geotechnical heterogeneity in terms of mechanical characteristics and of hydrogeological conditions. If we add to this the simultaneous presence of moderate to significant seismicity and considerable hydrological variability, it is easy to understand why significant slope instability events frequently occur. Of the approximately 850,000 landslides recorded in European databases (Herrera et al., 2017), almost two-thirds are contained in the Inventory of Landslide Phenomena in Italy (IFFI Project) compiled by ISPRA † (ISPRA, 2021). The Anas road network (Fig. 1), consisting of over 32,000 km of roads and motorways affected by heavy traffic (both cars and lorries), covers the entire national territory and is, therefore, highly exposed to the risk of landslides. In fact, it interferes with thousands of situations of slope instability. ISPRA data reveal that, out of a total of 500,000 recorded events (landslides of various types and characteristics), over 6,000 have affected Italian main infrastructure network. Risk reduction issues concern both existing road works and those in the design and construction phase.

Fig. 1. Anas road network (2025).

2. Tunnel Management The total number of road tunnels in the Anas network currently exceeds 2,100. They are not evenly distributed along the network but are mainly concentrated in the mountainous areas of northern, central and southern Italy, and are therefore highly exposed to geological hazards (Fig. 2).

2 ISPRA – Istituto Superiore per la Protezione e la Ricerca Ambientale, the Italian National Research Institute for Environmental Protection.