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

• Lyssbach, Flood Protection Lyss, Relief Tunnel (415 Ko)

• Preliminary project
• Construction project, project approval process
• Tendering
• Project implementation, construction management and supervision