Cleuson-Dixence Construction SA
- Scheme design: 2004 – 2006
- Construction: 2006 – 2009
In association with Electricité de France (EdF; CIH) and Stucky Ingénieurs-Conseils SA.
The Cleuson-Dixence hydroelectric dam was commissioned in 1998. That project enabled the extraction of the potential energy from all the water of the Grand Dixence dam at one location (hydraulic head 1,880 m, flow rate 75 m3/s). On the 12th December 2000, the penstock suddenly ruptured, and the water escaped to the surface.
This rehabilitation project involved lining the entire length of the penstocks (approximately 4 km) and bypassing the section damaged in the accident, which required the construction of two new access galleries and underground caverns at the elbows.
In order to reinforce the shafts, the original access shafts which had been infilled with concrete were required to be reopened.
Before the lining of the shafts was undertaken, the ground around the shafts was stabilised from inside the shafts using grout injection which enabled the interstitial voids present at the top of the existing lining to be filled.
Scheme design outline and detail; management of the tender process; construction design; and direction of the rehabilitation works of the penstock of the Cleuson-Dixence hydroelectric dam, which was taken out of service in December 2000.