SharePoint
Aide
IRSN, Institut de radioprotection et de sûreté nucléaire

Search our site :

ok

Contact us :

ok
En Fr

Enhancing Nuclear Safety


Research

Publications

Extension of the desaturated zone around structures excavated in the Tournemire argillite by means of petrophysical measurements coupled to gas tests


Congress ttile :Clays in natural and engineered barriers for radioactive waste confinement
Congress town :Tours
Congress date :14/03/2005

Document type > *Congrès/colloque

Keywords >

Research Unit > IRSN/DEI/SARG/LETS

Authors > KECH Michae, LEMIUS Sylvain, MATRAY Jean-Michel, SAVOYE Sébastien

Publication Date > 25/04/2005

Summary

Studies carried out on URL constructed in compacted argillaceous formations like in Mont Terri and Tournemire have demonstrated the occurrence of a rock de-saturation around tunnels or drifts as a consequence of excavation works and drift ventilation. The Tournemire URL owns structures realized at three distinct periods: a century-old tunnel and drifts excavated in 1996 and 2003. It is also characterized by the appearance of desiccation fractures in the drifts. This behavior has conducted IRSN to record since 1999 the properties (Relative humidity and temperature) of the air ventilating the different structures. Time series have shown seasonal cycles for the Relative Humidity and temperature that are negatively correlated with a mean annual RH and temperature values of ca 70% and 10°C, respectively. These variations produced hydration/dehydration cycles at the structure walls since their excavation. These cycles explain the shrinkage/swelling behavior of the rock and the subsequent opening and closure of inter-layers spaces (Valès et al., 2004). However, the too short periods of saturated-air conditions did not allow a complete re-saturation of the rock at the structure wall that progressively de-saturates. This study aims to assess the extension of this de-saturation with time and location by means of densitometric petrophysical measurements coupled to pneumatic tests. This abstract presents the main results of the first 2m borehole dedicated to this study and that was drilled parallel to bedding in the most recent drift excavated in 2003
Send Print

More about

Contact


Close

Send to a friend

The information you provide in this page are single use only and will not be saved.
* Required fields

Recipient's email:*  

Sign with your name:* 

Type your email address:*   

Add a message :

Do you want to receive a copy of this email?

Send

Cancel

Close

WP_IMPRIMER_TITLE

WP_IMPRIMER_MESSAGE

Back

Ok