Starting in 2024, the Swiss Tunnel Congress (STC)—Switzerland’s premier event for underground construction—will be held exclusively in even-numbered years. To maintain momentum in the intervening years, the Swiss Tunnelling Society (STS) has introduced the Swiss Tunnel Day (STDay), a one-day congress dedicated to showcasing the latest developments in the field.
This year’s STDay took place on 12 June 2025 at the Congress Centre in Biel/Bienne. Organised by the STS with strong support from its Young Members group, the event provided a compact yet comprehensive platform for professionals to explore recent advances in underground construction. The format offered attendees the opportunity to engage in technical discussions, share knowledge, and network with peers—all within a single day.
Switzerland is entering a dynamic phase of infrastructure development, with several major underground projects on the horizon. These include:
- Zimmerberg Base Tunnel Phase 2, which will extend the existing 9.4 km tunnel from Zurich–Thalwil to Litti, near Zug;
- Completion of the second tube of the Lötschberg Base Tunnel;
- The Morges–Perroy railway tunnel, an 8 km connection between Lausanne and Geneva;
- Doubling of the Gotthard road tunnel, already underway;
- And the Lugano TramTreno metro line, with construction expected to begin shortly.
As the sector evolves, new technologies such as digitalisation and sustainable construction practices are reshaping the landscape of tunnel engineering. The STS remains committed to addressing these challenges and playing a leading role in driving innovation and developing forward-thinking solutions for the future of underground infrastructure.
The STDay 2025 conference featured a mix of high-level presentations by clients, designers and contractors:
- Teaching tunnel construction – generating enthusiasm for tunnel construction
- Underground extension of Geneve station (through station)
- N4 New Axenstrasse – Tunnel construction in the Swiss Pre-Alps
- Second tube of the Gotthard road tunnel: northern fault zone
- The Swiss deep repository
- Renovation of the eastern adduction tunnels of the Hongrin hydroelectric infrastructure
- Le Locle bypass
- Chlus hydroelectric project in the canton of Graubünden
- Access tunnel to Sigirino (Ceneri Base Tunnel)
- Kaiserstuhl tunnel on the N8 in the canton of Obwalden
For the further information click here and also please visit https://www.swisstunnel.ch/ . 25/25.
