FRACOD Modeling of Rock Fracturing and Permeability Change in Excavation-Damaged Zones
Publication: International Journal of Geomechanics
Volume 11, Issue 4
Abstract
The characterization of the excavation-damaged zone (EDZ) around an underground excavation is a major research topic for deep geological disposal of medium- to high-level radioactive waste. Rock fracturing because of excavation and thermal loading and its resultant rock mass permeability change in the EDZ are important for construction projects and long-term safety. A new function to predict rock mass permeability change in fractured rocks has been developed and added to the existing fracture mechanics code FRACOD. The new functions in FRACOD have been applied to predict the extent of EDZ and permeability change in the vicinity of the tunnel sealing experiment (TSX) tunnel of the Underground Research Laboratory (Canada), the zone of excavation disturbance experiments (ZEDEX) tunnel of the Äspö Hard Rock Laboratory (Sweden), and the deposition tunnels in crystalline and sedimentary rocks (Japan). The predicted EDZ and its permeability are consistent with the measurement data of the TSX tunnel and ZEDEX tunnel. The results from both tests indicate that FRACOD with the new function is capable of realistically predicting the EDZ and permeability change.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The development of the permeability function in FRACOD and the conduction of validation tests were kindly supported by the Hazama Corporation, Japan.
References
Chryssanthakis, P., Tunbridge, L., and Christiansson, R. (2003). “Numerical modelling in 3D of the TBM/ZEDEX tunnels at Äspö, Hard Rock Laboratory and comparison with in-situ measurements.” Proc., Underground Construction Conf., London.
Emsley, S., Olsson, O., Stenberg, L., Alheid, H.-J., and Falls, S. (1997). “Zedex—A study of damage and disturbance from tunnel excavation by blasting and tunnel boring.” SKB Technical Rep. 97-30, Swedish Nuclear Fuel and Waste Management Co., Stockholm, Sweden.
Hajiabdolmajid, V., Kaiser, P. K., and Martin, C. D. (2002). “Modelling brittle failure of rock.” Int. J. Rock Mech. Min. Sci., 39(6), 731–741.
Martino, J. B., and Chandler, N. A. (2004). “Excavation-induced damage studies at the Underground Research Laboratory. Int. J. Rock Mech. Min. Sci., 41(8), 1413–1426.
Rinne, M., Shen, B., and Lee, H.-S. (2003a). “Äspö Hard Rock Laboratory. Äspö pillar stability experiment. Modelling of fracture stability by FRACOD. Preliminary results.” SKB IPR-03-05, Swedish Nuclear Fuel and Waste Managing Co., Stockholm, Sweden.
Rinne, M., Shen, B., Lee, H.-S., and Jing, L. (2003b). “Thermo-mechanical simulations of pillar spalling in SKB APSE test by FRACOD.” GeoProc2003, Int. Workshop, Stockholm.
Shen, B. (2002). FRACOD Version 1.1 user’s manual, FRACOM Ltd., Kyrkslätt, Finland.
Shen, B., and Stephansson, O. (1994). “Modification of the G-criterion for crack propagation subjected to compression.” Eng. Fract. Mech., 47(2), 177–189.
Shen, B., Stephansson, O., and Rinne, M. (2002). “Simulation of borehole breakouts using .” Oil Gas Sci. Technol., 57(5), 579–590.
Souley, M., Homand, F., Pepa, S., and Hoxha, R. (2001). “Damage-induced permeability changes in granite: A case example at the URL in Canada.” Int. J. Rock Mech. Min. Sci., 38(2), 297–310.
Stephansson, O., et al. (2003). “Mechanical evaluation and analysis of research shafts and galleries in MIU Project, Japan (Paper No. UE03-K9).” 1st UE Kyoto Symp., Kyoto, Japan.
Tsang, C.-F., Bernier, F., and Davies, C. (2005). ”Geohydromechanical processes in the excavation damaged zone in crystalline rock, rock salt and indurated and plastic clays—In the context of radioactive waste disposal.” Int. J. Rock Mech. Min. Sci., 42(1), 109–125.
Information & Authors
Information
Published In
International Journal of Geomechanics
Volume 11 • Issue 4 • August 2011
Pages: 302 - 313
Copyright
© 2011 American Society of Civil Engineers.
History
Received: Sep 2, 2009
Accepted: Apr 7, 2010
Published online: Apr 10, 2010
Published in print: Aug 1, 2011
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.