A joint venture team of Implenia and Frutiger, known as Secondo Tubo, has been awarded a £408 million (US$409 million) contract to construct the second Gotthard road tunnel.
The contract, awarded by Swiss Federal Roads Office (Fedro), calls for Secondo Tubo to construct 7.9 km (5 miles) of tunnels working from the north portal for the project with the work expected to be completed in 2029. A separate contract will be awarded for the excavation of the 9 km (5.6 mile) long southern section of tunnel.
New Civil Engineer reported that the second Gotthard road tunnel is being constructed to relieve traffic using the existing tunnel in the long term but before both tunnels are put into use at the same time, the existing tunnel will be refurbished. Both tunnels are expected to be in operation by 2032. The project is not planned to increase capacity as only one lane will be open in either direction even when both tubes are open.
Secondo Tubo will use a tunnel boring machine (TBM) to complete a 7.3 km (4.5 mile) tunnel with a 12.3 m (40 ft) diameter. Before work started on the main TBM bored tunnel, a 160 m (525 ft) long drill and blast excavated tunnel will be constructed from the tunnel portal site. The work also includes 430 m (1,410 ft) of drill and blast excavated tunnel in a geotechnical complex section within the middle of the 7.9 km (5 miles) tunnel, which will be undertaken from a 4 km (2.4 miles) access tunnel that is currently being constructed under a separate contract.
When the TBM reaches this 430 m (1,410 ft) section, it will be pulled through and overhauled before being relaunched to complete the tunneling for the contract.
In addition, Secondo Tubo will also construct two underground ventilation facilities and establish a concrete production plant and precast concrete lining casting facilities within former military caverns.
According to Fedro, Secondo Tubo secured the work based on both the quality and price, as well as the experience of the staff that will be deployed on the project.
“The second tube of the Gotthard road tunnel will make a major contribution to improving the north-south road link in Switzerland,” Implenia CEO André Wyss said. “We are delighted to be planning and building this large and complex infrastructure project, which is an excellent fit with Implenia’s strategy. We will contribute our many years of experience and proven expertise in tunnel construction and other civil engineering disciplines to this exciting project.”
According to Fredo, assembly of the TBM on site for the work is expected to start in autumn next year with excavation of the 430 m (1,410 ft) section of drill and blast tunnel starting in summer 2024.
Photo: Stone tall bridges named as the Devil’s Bridge at St Gotthard Pass with arcs and mountain river with azure water. Shutterstock.