Excavation damaged zones in the argillaceous Tournemire site: characterization and failure mechanisms
Titre du congrès :Clays in natural and engineered barriers for radioactive waste confinement
Ville du congrès :Lille
Date du congrès :17/09/2007
For repository safety assessment purposes, the analysis of the engineered openings behaviour concerns specifically the possible creation of an Excavation Damaged Zone (EDZ). A complete control of the evolution of this EDZ over space and time is essential for long-term repository safety. Studies are ongoing in Underground Research Laboratories around the world in order to better understand the fracturing process developed around the excavated openings in the considered rock and changes over time of the hydro-mechanical and the geochemical properties of this zone.
This paper presents a synthesis of the whole experimental results, emphasizing on the characterisation in space and time of the EDZs existing in the Tournemire site. The identification of the failure mechanisms associated with the creation and evolution of these zones is also described. Here, the term EDZ refers to the zone where fractures develop due to failure of the rock mass.