News

The Belchen road tunnel was opened in 1970 and consists of two separate twin-lane tubes with unidirectional traffic, each having a length of 3.2 km. In early 2021, with the so-called rehabilitation tunnel going into operation, the Belchen tunnel system will comprise three twin-lane tunnels. ILF Consulting Engineers is also involved in the design and construction of the rehabilitation tunnel.

Extensive rehabilitation works were already carried out on the existing road tunnel from 2001 to 2003. However, the swelling rock (anhydrite) is increasingly leaving visible traces. In order to ensure the safety and capacity of one of Switzerland’s busiest roads, the two existing tunnels at Belchen will be refurbished one after the other as part of the second rehabilitation.

The intended measures include the replacement of parts of the in-situ lining, backfilling of cavities that were detected in the crown, design of utility lines and fire-fighting system, and expansion/new construction of cross passages. Water ingress in connection with swelling anhydrite are the great challenges in these complex ground conditions.

Being part of the design consortium, ILF was tasked with developing and implementing the project up to commissioning by the Swiss Federal Roads Office (FEDRO). The project was launched in June 2020 and is expected to be concluded by mid-2032.