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Author Balland, Cyrille ♦ Morel, Jacques ♦ Armand, Gilles ♦ Pettitt, Will
Source Hyper Articles en Ligne (HAL)
Content type Text
Publisher Pergamon
File Format PDF
Language English
Subject Keyword MINE-BY-TEST ♦ EXCAVATION-DAMAGED ZONE ♦ VELOCITY SURVEY ♦ ANISOTROPY ♦ sdu ♦ sde ♦ Sciences of the Universe [physics]/Earth Sciences ♦ Environmental Sciences
Abstract The excavation of a deep underground structure induces a stress field redistribution that could create an excavation-damaged zone (EDZ). The study of the EDZ is important in the framework of nuclear waste storage, where such EDZ could constitute a preferential pathway of stored material towards the biosphere. Analysis of ultrasonic wave propagation across the rock media around the excavation is one technique that can be used to characterize such zones. This method has been applied in the Meuse/Haute-Marne Underground Research Laboratory (URL) in France to characterize the initialization and evolution of damage around the URL access shaft. To achieve this, a device comprising 21 ultrasonic sensors was spread out at different distances from the shaft wall, at depths between -465 and -475 m. A transversely isotropic model enabled the measured experimental velocities on each ray path during shaft excavation to be integrated. The results highlighted the initialization and extension of the damage as the shaft front proceeded. They also showed a polarization of the velocity field and an oscillation of the transversal isotropy with a preferential orientation of the stress release and the microcracking. Monitoring of the velocity field also highlighted some significantly different behaviour linked to the complex mechanical behaviour of the argillaceous rock.
ISSN 13651609
Educational Use Research
Learning Resource Type Article
Publisher Date 2009-01-01
Journal International Journal of Rock Mechanics and Mining Sciences
Volume Number 46
Issue Number 1
Page Count 11
Starting Page 69
Ending Page 79