Cigeo project: geotechnical investigations are completed
The 67 boreholes drilled on the old railway path between Gondrecourt-le-Château (55) and Cirfontaine-en-Ornois (52) and of the new track between Cirfontaine-en-Ornois and Gillaumé will allow Andra to better characterize the land that could accommodate the rail link between the railway networks and the Cigeo terminal, if the disposal facility is authorized.
The project owner, Andra, initiated these investigations along the old railway line last October. A drilling campaign was contracted to the Fondasol company. Its objective: to obtain all the necessary data for the possible construction of the "branched terminal installation" (ITE), the new portion of railway connecting Cigéo to the railway network with a new section of 14 km.
It is therefore important, to consolidate studies and files for future authorization requests, to fully understand the soil behavior and its capacity to accommodate the ITE, especially since the project under study includes nine bridges.
67 boreholes
"The site survey was completed on time and in good safety conditions," says Frédéric L’Honneur, the Andra coordinator of operations . A total of 67 holes were drilled. Some were cored to study the characteristics of the soil, others to measure its mechanical strength.. This campaign involved a dozen people, spread over three different sites. On this occasion, piezometers were also installed on a dozen boreholes, in order to measure seasonal variations in the height of the water table.
What next ?
The drilling equipment and excavators present near Gondrecourt-le-Château, Horville-en-Ornois, Cirfontaines-en-Ornois, Gillaumé or Saudron now leave the premises. "Only the sheltered piezometers will remain, which will allow Andra to take readings in order to regularly monitor the level of groundwater," said Frédéric L’Honneur. Fondasol, supported by laboratories, will now be responsible for analyzing all the results obtained,during this drilling campaign. Data collected will feed into the so-called "project study" phase, which will last from 12 to 18 months. At the same time, Andra will submit its declaration of public utility (DUP) file as well as an Impact Assessment Study in a few months. A long process to finalize before the next phases of the project can be initiated.
