Environmental Geology

, Volume 57, Issue 6, pp 1325–1335 | Cite as

Study of the initiation and propagation of excavation damaged zones around openings in argillaceous rock

  • Alain Millard
  • Jobst Maßmann
  • Amel Rejeb
  • Shin Uehara
Special Issue


The study of the creation and evolution of the excavation disturbed zone (EDZ) in argillaceous rocks is a major issue for the safety of nuclear wastes underground repositories. In this context, the argillaceous Tournemire site has provided a unique opportunity to study the evolution of the EDZ with time thanks to the existence of three openings of different ages. A thorough characterization of the EDZ has been conducted by different means such as visual observation, analysis of samples extracted from drilled boreholes, EDZ permeability measurements, etc. On the basis of these measurements, a conceptual model of the EDZ initiation and propagation at the Tournemire site has been proposed. In order to validate this model, numerical simulations of increasing complexity have been carried out. In a first attempt, the response of the rock mass to the excavation phase, followed by seasonal cyclic variations of temperature and relative humidity inside the opening, has been simulated by means of a purely mechanical analysis, using a simple elastic material model. The EDZ has been estimated by post-processing the calculated stress states, using a Mohr–Coulomb failure criterion. The results obtained show that no EDZ could be predicted unless adopting a low cohesion value for the rock mass. Moreover, the deferred nature of the EDZ formation in Tournemire could not be reproduced. These limitations have then been suppressed by using a coupled viscoplastic-damaging mechanical model, the parameters of which have been identified from different laboratory experiments. With this model, a time evolution of the EDZ could be predicted, but the EDZ pattern could not match the one observed in situ. Finally, in view of the importance of the hydraulic couplings, unsaturated hydro-mechanical calculations have been carried out to investigate the effect of the numerous seasonal variations cycles and the resulting shrinkage.


Excavation Argillite Damage Numerical simulation Hydro-mechanical coupling 



The authors like to acknowledge the Institut de Radioprotection et de Sûreté Nucléaire (IRSN), France, for providing the in situ data. The work was supported in parts by the Commisariat à l’Energie Atomique (CEA), France.


  1. Bear J, Bachmat Y (1990) Introduction to modeling of transport phenomena in porous media. Kluwer, DordrechtCrossRefGoogle Scholar
  2. Biot M (1941) General theory of three dimensional consolidation. J Appl Phys 12:155–164CrossRefGoogle Scholar
  3. Boidy E, Pellet F, Boulon M (2001) Numerical modelling of deep tunnels including time-dependent behaviour. In: Boehler JP (ed) Euromech 115 conference, pp 737–759, Villard de LansGoogle Scholar
  4. Cabrera J (2002) Caractérisation des discontinuités en milieu argileux (station expérimentale de Tournemire). IRSN Scientific and technical report, p 227–232Google Scholar
  5. Lemaitre J, Chaboche JL (1985) Mécanique des matériaux. Dunod, ParisGoogle Scholar
  6. Lewis RW, Schrefler BA (1998) The finite element method in the static and dynamic deformation and consolidation of porous media. Wiley, ChichesterGoogle Scholar
  7. Massmann J, Uehara S, Rejeb A, Milllard A (2008) Investigation of desaturation in an old tunnel and new galleries at an argillaceous site. Environ Geol (this issue)Google Scholar
  8. Rejeb A (2003) Time dependent behavior of Tournemire argillites (France). In: Proceedings of the ISRM conference, South AfricaGoogle Scholar
  9. Rejeb A (2005) Disturbances caused by the excavation of a gallery in the Tournemire site in 2003. In: Safety of the geological disposal of radioactive waste, scientific and technical report, Institute of Radioprotection and Nuclear Safety (IRSN), FranceGoogle Scholar
  10. Rejeb A, Cabrera J (2004) DECOVALEX-THMC, Description for Task C, Excavation Disturbed Zone (EDZ) in the argillaceous Tournemire site (France). Technical report, Institute of Radioprotection and Nuclear Safety (IRSN), FranceGoogle Scholar
  11. Rejeb A, Cabrera J (2006) Time-dependent evolution of the excavation damaged zone in the argillaceous Tournemire site. In: Proceedings of the GeoProc international conference on coupled T–H–M–C processes in geosystems. 22–25 May Nanjing, P.R. China, pp 65–74Google Scholar
  12. Rejeb A, Millard A, Uehara S, Massmann J (2008) Hydro-mechanical analysis of a mine-by-test experiment performed in argillite at the Tournemire site. Environ Geol (this issue)Google Scholar
  13. Rouabhi A, Tijani M, Rejeb A (2007) Triaxial behavior of transversely isotropic materials: application to sedimentary rocks. Int J Num Anal Meth Geom 31(13):1517–1535CrossRefGoogle Scholar
  14. van Genuchten MT (1980) A closed-form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Sci Soc Am 44:892–898CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Alain Millard
    • 1
  • Jobst Maßmann
    • 2
  • Amel Rejeb
    • 3
  • Shin Uehara
    • 4
  1. 1.Commissariat à l’Energie Atomique, CEN SaclayGif sur YvetteFrance
  2. 2.Institute of Fluid Mechanics and Computer Applications in Civil EngineeringLeibniz Universität HannoverHannoverGermany
  3. 3.Institut de Radioprotection et de Sûreté NucléaireFontenay-aux-RosesFrance
  4. 4.Department of Urban and Environmental EngineeringKyoto UniversityNishikyo-KuJapan

Personalised recommendations