The joint venture between BESIX (Belgium) and Donati (Italy) has successfully completed the excavation of the Casacastalda Tunnel, marking a major milestone in the upgrade of State Road 318 (SS 318), a strategic infrastructure project commissioned by ANAS, the Italian national road authority.
Festive milestone
The end of the excavation works was marked by an official event held on site in the presence of Francesco De Rebotti, Councillor for Economic Development, Labour Policies, Mobility and Transport, Infrastructure of the Umbria Region, Lamberto Nicola Nibbi, Head of ANAS Umbria, Angelo Donati, CEO of Donati and Nic De Roeck, General Manager of BESIX Europe. The ceremony celebrated this major milestone and acknowledged the collaborative efforts of all teams involved in delivering a complex and technically demanding phase of the project.
Casacastalda Tunnel
The Casacastalda Tunnel, which extends 1,545 meters, is part of the 3.13-kilometre Valfabbrica section, designed to improve traffic flow and safety between Perugia and Ancona. Alongside the Casacastalda Tunnel, the project also includes the construction of the 874-meter Picchiarella Tunnel, the 130-meter Tre Vescovi Viaduct, and the 60-meter Calvario Bridge.
Excavation of the Casacastalda Tunnel began in February 2022, using the New Austrian Tunneling Method (NATM). The teams used a combination of steel arch support and sprayed concrete to stabilise the underground structure, ensuring a safe working environment. The tunnel’s structure was completed using cast-in-place concrete lining, placed over a waterproofing membrane.
“Excavating a new tunnel adjacent to a traffic-active tunnel is an extremely delicate operation, as any error could have dramatic consequences. Throughout the excavation process, we have had to closely monitor the existing tunnel to ensure that the work has no negative impact on its integrity. Additionally, we have navigated complex geological formations, primarily consisting of multi-colored clays and the Marnoso-Arenacea formation”, said Hervé Jourquin, Deputy Project Manager for BESIX.
Next steps
With excavation now complete, works will proceed with the tunnel lining, hydraulic, mechanical and electrical systems, and final road surfacing. The Valfabbrica project, awarded in 2020, remains on track for completion in 2026.
“This new successful milestone confirms BESIX’s capabilities to deliver complex, large-scale infrastructure in challenging environments, from design through to execution,” said Jan Van Steirteghem, COO of BESIX Construction. “We are proud to contribute to modernising Italy’s transport network alongside our partners and our client, ANAS.”
The project also paves the way for BESIX and Donati’s next collaboration with ANAS, in the city of Ancona, where they will soon begin construction on a new 1.8-kilometre road segment, including two tunnels and a viaduct, further improving mobility along the SS 76 corridor.
