Lyssbach, Flood Protection Lyss, Relief Tunnel
The 2,570 m long relief tunnel passes from Leen at the southern entry to the town of Lyss up to Fulenmatt where the Lyssbach flows into the Alte Aare. With a capacity of 68m3/s the tunnel can cope with 1.5 times the water of a hundred year flood.
The following servies were provided by IUB Engineering AG:
- Excavation pit with nail walls at the inlet and outlet structure within close vicinity of the SBB railway line and the road.
- Underpass below an operational SBB railway line using a provisional bridge on micro piles. Finally, a concrete frame bridge was inserted.
- Road underpass and road shifting
- Concrete inlet and outlet structures at the relief tunnel
- Grade tunnel using cut and cover method
- Hydraulic engineering, scouring protection
- Hydraulic steelwork
- Length of relief tunnel: 2,570 m
- Inner diameter: 4.2 m
- Capacity: 68 m³/s
- Gradient: 0.58 %
Scope of services
- Preliminary project
- Construction project, project approval process
- Project implementation, construction management and supervision