Romande Energie Renouvelable SA
May / December 2012
The seismic verification of the barrage du Day (Les Clées) and the spillway tower in accordance with the OFEN (Swiss Federal Office of Energy) Directive for the seismic verification of storage structures.
This gravity dam was built in 1955 on the Orbe river in the Canton of Vaud. Its main characteristics are:
- Maximum height of 32 m;
- volume of the dam: 26 500 m3;
- volume of the reservoir: 740 000 m3;
- length of the crest: 100 m;
- surface area of the catchment area: 288 km2;
- spillway capacity: 170 m3/s;
- type of spillway: circular spillway tower;
- capacity of the purge valve: 100 m3/s;
- capacity of the drainage valve: 32 m3/s;
- name of the plant: Usine des Clées;
- hydraulic head: 174.15 m;
- installed power: 27.5 MW;
- turbinable flow rate: 21 m3/s.
Within this project, the following was carried out by BG:
- inspection an measurement of the natural frequencies of the dam;
- finite element modelling;
- calibration of the model based on the on-site;
- static and dynamic analyses;
- verification of the stability of the barrage.
In line with the OFEN Directive, this is a class II barrage which would experience a peak ground acceleration of 0.13 g during the verification earthquake, which has a return period of 5,000 years.
Seismic verification of the "barrage du Day" (Les Clées)