Del Fico Tunnel and San Bernardo Tunnel – A12 Genoa–Sestri Levante

Del Fico Tunnel

Crezza was commissioned to a renovation of the “Del Fico” motorway tunnel on the A12 motorway, in the Genoa–Sestri Levante section, an infrastructure built in the 1960s. The tunnel is approximately 240 meters long, predominantly excavated in natural rock, and features a two-lane carriageway with a width of 9.10 meters. The interventions involved the renovation of the low walls and the final lining, in addition to complementary works.

Crezza was responsible for the prefabrication and installation of the lining, which consisted of precast lattice segments along the entire tunnel route, including special custom-designed segments for the construction of flute-shaped tunnel entrances, which did not exist before. The company designed and prefabricated 100 wedge shaped lining rings of varying widths from 2.40 to 2.34 meters, each of which consisted of 2 pier elements and 1 cap element, for a total of 300 precast elements realized.

Following preparatory works, including milling, waterproofing, and low wall construction, Crezza installed the components using its own personnel and specialized equipment, ensuring quick installation despite the very limited milling thickness (about 30-35 cm, with only 8-10 cm beyond the total thickness of the precast element).

San Bernardo Tunnel

In the same section of the A12 Genoa–Sestri Levante motorway, Crezza was commissioned to a renovation of the “San Bernardo” motorway tunnel, an older structure, with a project that involved the demolition of the existing lining, the renovation of the low wall, the installation of structural metal armour-plate, and complementary works. The tunnel, predominantly excavated in natural rock, extends for a length of 92 meters and features a two-lane carriageway with a width of 9.10 meters.

Crezza was responsible for the production and installation of the metal armour-plate along the entire length of the tunnel and at the entrances, producing 61 lining rings, each 1.50 meters wide, composed of 2 pier elements and 1 cap element, totaling 183 precast elements. After the preparatory works, including milling, waterproofing, and low wall construction carried out by other companies within the consortium (ATI), Crezza swiftly installed the components, despite the very limited milling thickness.

The decision to adopt metal armour-plate instead of the standard solution of precast segments was due to the higher stresses transmitted by the excavation section. In collaboration with its partners, Crezza produced the metal framework in-house to create a pre-assembled structure for on-site installation. The structure, consisting of curved metal beams, sheets, and fasteners, was galvanized after processing to ensure the required durability. Finally, the installation was completed by Crezza’s personnel using specialized equipment.