Renovation of Colle Marino Tunnel – A14 Pineto Atri (TE)

The project involved the renovation of the “Colle Marino” motorway tunnel on the A14 in the Pineto-Atri section, located in the province of Teramo, work carried out in the 1970s. This tunnel extends for approximately 950 meters, of which 800 meters were excavated in natural rock, and it features a two-lane carriageway with a width of 9.60 meters. The interventions included the renovation of the invert arch and the final lining, in addition to complementary works.

In 2023, Crezza was commissioned to prefabricate and install the tunnel’s lining, composed of lattice precast segments, and to produce and install the metal armour-plate at the tunnel entrances.

After Crezza’s technicians completed the design of the components, the prefabrication process began, producing 380 lining rings, each 2.40 meters wide, consisting of 2 pier elements and 1 cap element, for a total of 1,140 precast elements. After the preparatory works of milling, waterproofing, and low wall construction carried out by the contractor, Crezza installed the components directly using its own personnel and specialized equipment, ensuring rapid installation despite the limited milling thickness (approximately 32 cm, only 5-7 cm more than the total thickness of the precast elements).

At the tunnel entrances, where the transmitted stresses were higher, the project included the installation of metal armour-plate. In collaboration with its partners, Crezza produced the metal framework in-house to create a pre-assembled structure for on-site installation. The structure, composed of curved metal beams, sheets, and fasteners, was galvanized after processing to ensure the required durability. Finally, the installation was carried out by Crezza’s personnel using specialized equipment.