HWS Baltschiederbach Lot 3

• Client: Baltschieder municipality
• Construction management/contact person: Nicola Kalbermatten, Teysseire & Candolfi AG, Visp
• Site manager: Iwan Rieder
• Foreman: Pietro Pratico
• Construction period: October 2023 – October 2025 
• Construction costs: CHF 4.5 million

Technical data:

• 230 m² bridge formwork / falsework bridge
• 600 m³ concrete construction bridge/abutment/Lehnen viaduct 
• 162 m1 prestressing cable bridge deck 
• 150 tons reinforcement 
• 28³ m ultra-high-strength concrete (UHFB) 
• 7800m³ excavation 
• 800m utility line construction 
• 12,000 tons block revetments and base paving for bank protection 
• 400 m1 stream channel widening 
• 300 m1 traffic diversion on cantonal road via temporary auxiliary bridge 
• 1,100 tons of pavement installation 

Project description:

The “Baltschiederbach flood protection, stages 2 and 3 – public consultation project” involves enlarging the cantonal road culvert by building a new cantonal bridge and widening the channel on the left bank north of the cantonal bridge along the Baltschiederbach stream. A console (60 m long) and a connecting embankment wall (30 m long) are planned for the channel widening; further north, the widening will be achieved solely by excavation work on the left bank. 

In connection with the Baltschieder flood protection project, lot 3, Walpen AG widened the existing channel of the Baltschiederbach stream from the sediment collector to the cantonal road bridge in the first phase. The entire stream bed and the banks were constructed using block structures and bed paving. 

In front of the cantonal road bridge, a 60-meter-long lean-to viaduct was built in in-situ concrete as a transition to the new bridge. 

After rerouting the cantonal road to a temporary road and via a new temporary bridge made of in-situ concrete elements, the existing cantonal road bridge was demolished and a new replacement bridge was built. The new cantonal road bridge over the Baltschiederbach stream was constructed using a bottom formwork, so that the flow of the Baltschiederbach stream was maintained at all times.  

All work in and around the stream had to be carried out during the respective low water periods, from October to April. 

Requirements:

• Construction work in the area of a busy cantonal road 
• Relocation of cantonal road over a length of approx. 300 m 
• Scaffolding over existing Baltschiederbach 
• Construction of a temporary auxiliary bridge made of concrete slabs for traffic diversion 
• Work in the stream bed (Baltschiederbach) during low water periods  
• Earthworks in flowing water (water diversion and drainage)