Advertisement

Geomechanical behaviour of Opalinus Clay at multiple scales: results from Mont Terri rock laboratory (Switzerland)

  • Florian Amann
  • Katrin M. Wild
  • Simon Loew
  • Salina Yong
  • Reto Thoeny
  • Erik Frank
Chapter
Part of the Swiss Journal of Geosciences Supplement book series (SWISSGEO, volume 5)

Abstract

The paper represents a summary about our research projects conducted between 2003 and 2015 related to the mechanical behaviour of Opalinus Clay at Mont Terri. The research summarized covers a series of laboratory and field tests that address the brittle failure behaviour of Opalinus Clay, its undrained and effective strength, the dependency of petro-physical and mechanical properties on total suction, hydro-mechanically coupled phenomena and the development of a damage zone around excavations. On the laboratory scale, even simple laboratory tests are difficult to interpret and uncertainties remain regarding the representativeness of the results. We show that suction may develop rapidly after core extraction and substantially modifies the strength, stiffness, and petro-physical properties of Opalinus Clay. Consolidated undrained tests performed on fully saturated specimens revealed a relatively small true cohesion and confirmed the strong hydromechanically coupled behaviour of this material. Strong hydro-mechanically coupled processes may explain the stability of cores and tunnel excavations in the short term. Pore-pressure effects may cause effective stress states that favour stability in the short term but may cause longer-term deformations and damage as the pore-pressure dissipates. In-situ observations show that macroscopic fracturing is strongly influenced by bedding planes and faults planes. In tunnel sections where opening or shearing along bedding planes or faults planes is kinematically free, the induced fracture type is strongly dependent on the fault plane frequency and orientation. A transition from extensional macroscopic failure to shearing can be observed with increasing fault plane frequency. In zones around the excavation where bedding plane shearing/shearing along tectonic fault planes is kinematically restrained, primary extensional type fractures develop. In addition, heterogeneities such as single tectonic fault planes or fault zones substantially modify the stress redistribution and thus control zones around the excavation where new fractures may form.

Keywords

Clay shale Excavation damaged zone Undrained shear strength Pore-pressure response Suction Tectonic structures Nuclear waste disposal 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Notes

Acknowledgements

Most of the funding of the projects described in this article was provided by the Swiss Federal Nuclear Safety Inspectorate (ENSI) with cost-sharing contributions from Swisstopo (Federal Office of Topography, Switzerland), BGR (Federal Institute for Geosciences and Natural Resources, Germany) and Chevron (USA). We also highly appreciate the scientific and technical contributions made by many partner organizations and scientists. Important partners of these projects have been ENSI (Martin Herfort, Meinert Rahn, Ernando Saraiva), BGR (Kristof Schuster, Torsten Tietz, Dieter Boeddener, Friedhelm Schulte, and Wilfried Stille), Swisstopo (Christophe Nussbaum, Nicolas Badertscher, Olivier Meier, David Ja¨ggi, Claude Giarardin, and Lukas Glur), University of Alberta at Edmonton (Derek Martin), CEMI (Peter Kaiser, Andrew Corkum), Queen’s University (Mark Diederichs), the Technical Universities of Torino (Marco Barla), TU Graz (Manfred Blümel), the Geodetic Metrology and Engineering Geodesy Group of ETH Zurich (Stephan Schütz, Florence Vaudan), and many colleagues and students from the Department of Earth Sciences at ETH (Corrado Fidelibus, Keith Evans, Frank Lemy, Valentin Gischig, Jonas von Rütte, Jürgen Hansmann, Freddy Xavier Yugsi Molina, Christian Haug, Sophie Gschwind, Sebastian Zimmer, Linda Wymann, Nicolas Kupferschmid, Patric Walter, Matthew Perras, Claudio Madonna, and Hansruedi Maurer). We are grateful two the two reviewers (Prof. Derek Martin and Dr. Bill Lanyon) for their valuable comments.

References

  1. Amann, F., Button, E. A., Evans, K. F., Gischig, V. S., & Blümel, M. (2011). Experimental study of the brittle behavior of clay shale in short-term unconfined compression. Rock Mechanics and Rock Engineering, 44(4), 415–430.Google Scholar
  2. Amann, F., Kaiser, P. K., & Button, E. A. (2012a). Experimental study of the brittle behavior of clay shale in rapid triaxial compression. Rock Mechanics and Rock Engineering, 45(1), 21–33Google Scholar
  3. Amann, F., Thoeny, R., & Martin, C. D. (2012b). Rock mechanical considerations associated with the construction of a nuclear waste repository in clay rock. In Proceedings of the 46th US Rock Mechanics/Geomechanics Symposium 2012, Chicago, American Rock Mechanics Association.Google Scholar
  4. Amann, F., Wild, K. M., & Martin, C. D. (2015). The role of capillary suction and dilatancy on the interpretation of the confined strength of clay shales. In Proceedings of the 13th International Congress of Rock Mechanics/Shale Symposium, 2015, Montreal, International Society for Rock Mechanics.Google Scholar
  5. Anagnostou, G. (2009). The effect of advance-drainage on the shortterm behavior of squeezing rocks in tunneling. In Proceedings of the International symposium on computational geomechanics, Juan-Les-Pins, France (pp. 668–679).Google Scholar
  6. Aristorenas, G. V. (1992). Time-dependent behavior of tunnels excavated in shale. Ph.D. dissertation, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.Google Scholar
  7. Badertscher, N., Girardin, C., & Nussbaum, C. (2008). SE-H Experiment: EDZ structural analyses of resin impregnated sections from BSE-3 overcores. Mont Terri Technical Note, TN 2008-15. Federal Office of Topography (swisstopo), Wabern, Switzerland. www.mont-terri.ch.
  8. Bellwald, P. (1990). A contribution to the design of tunnels in argillaceous rock. Ph.D. dissertation, Massachusetts Institute of Technology, Cambridge, Massachusetts, USAGoogle Scholar
  9. Bishop, A. W., & Eldin, G. (1950). Undrained triaxial tests on saturated sands and their significance in the general theory of shear strength. Géotechnique, 2(1), 13–32.Google Scholar
  10. Bobet, A., Aristorenas, G., & Einstein, H. H. (1999). Feasibility analysis for a radioactive waste repository tunnel. Tunnelling and Underground Space Technology, 13(4), 409–426.Google Scholar
  11. Bossart, P. (2008) Annex 4-12. In P. Bossart, & M. Thury (Eds.), Mont Terri Rock Laboratory. Project, Programme 1996 to 2007 and Results. Reports of the Swiss Geological Survey, No.3. Federal Office of Topography (swisstopo), Wabern, Switzerland. www.mont-terri.ch.
  12. Bossart, P., Bernier, F., Birkholzer, J., Bruggeman, C., Connolly, P., Dewonck, S., Fukaya, M., Herfort, M., Jensen, M., Matray, J-M., Mayor, J. C., Moeri, A., Oyama, T., Schuster, K., Shigeta, N., Vietor, T., & Wieczorek, K. (2017). Mont Terri rock laboratory, 20 years of research: introduction,site characteristics and overview of experiments. Swiss Journal of Geosciences.  https://doi.org/10.1007/s00015-016-0236-1 (this issue).
  13. Bossart, P., Trick, T., Meier, P. M., & Mayor, J.-C. (2004). Structural and hydrogeological characterisation of the excavation-disturbed zone in the Opalinus Clay (Mont Terri Project, Switzerland). Applied Clay Science, 26, 429–448.Google Scholar
  14. Corkum, A. G., & Martin, C. D. (2007). Modelling a mine-by test at the Mont Terri rock laboratory, Switzerland. International Journal of Rock Mechanics and Mining Sciences, 44, 846–859.Google Scholar
  15. Einstein, H. H. (2000). Tunnels in Opalinus Clayshale—A review of case histories and new developments. Tunnelling and Underground Space Technology, 15(1), 13–29.Google Scholar
  16. Giger, A. B., Marschall, P., Lanyon, B., & Martin, C. D. (2015). Hydro-mechanical response of Opalinus Clay during excavation works—A synopsis from the Mont Terri ROCK LABORATORY. Geomechanics and Tunneling, 8(5), 421–425.Google Scholar
  17. Golder, H. Q., & Skempton, A. W. (1948). The angle of shearing resistance in cohesive soils for tests at constant water content. In Proceedings of the Second International Conference of Soil Mechanics and Foundation Engineering, Vol. 1, (pp. 185–192).Google Scholar
  18. Islam, M. A., & Skalle, P. (2013). An experimental investigation of shale mechanical properties through drained and undrained test mechanisms. Rock Mechanics and Rock Engineering, 46, 1391–1413.Google Scholar
  19. ISRM. (1978). Suggested methods for determining tensile strength of rock materials. International Journal of Rock Mechanics and Mining Sciences & Geomechanical Abstracts, 15, 99–103.Google Scholar
  20. ISRM. (1979). Suggested methods for determining the uniaxial compressive strength and deformability of rock materials. International Journal of Rock Mechanics and Mining Science & Geomechanical Abstracts, 16(2), 135–140.Google Scholar
  21. Itasca (2009). Fast Langrangian Analysis of Continua in 3 dimensions, Version 4. Itasca Consulting Group, 438 Google Scholar
  22. Jaeggi, D., Nussbaum, C., Moeri, A., Shao, H., & Mueller, H. (2010). WS-H experiment: overcoring and structural analyses of the resin-impregnated BHG-B11 overcore under plane and UV light. Mont Terri Technical Note, TN 2010-32. Federal Office of Topography (swisstopo), Wabern, Switzerland. www.mont-terri.ch.
  23. Klinkenberg, M., Kaufhold, S., Dohrmann, R., & Siegesmund, S. (2009). Influence of carbonate micofabric on the failure strength of claystones. Engineering Geology, 107, 42–54.Google Scholar
  24. Kupferschmied, N., Wild, K. M., Amann, F., Nussbaum, C., Jaeggi, D., & Badertscher, N. (2015). Time-dependent fracture formation around a borehole in a clay shale. International Journal of Rock Mechanics and Mining Sciences, 77, 105–114.Google Scholar
  25. Marschall, P., Distinguin, M., Shao, H., Bossart, P., Enachescu, C., & Trick, T. (2006). Creation and evolution of damage zones around a microtunnel in a claystone formation of the Swiss Jura Mountains. In SPE International Symposium and Exhibition on Formation Damage Control, Society of Petroleum EngineersGoogle Scholar
  26. Marschall, P., Horseman, S., & Gimmi, T. (2005). Characterisation of gas transport properties of the Opalinus Clay, a potential host rock formation for radioactive waste disposal. Oil & Gas Science and Technology, 60(1), 121–139.Google Scholar
  27. Martin, C. D. (1997). Seventeenth Canadian Geotechnical Colloquium: The effects of cohesion loss and stress path on brittle rock strength. Canadian Geotechnical Journal, 34, 698–725.Google Scholar
  28. Martin, C. D., Lanyon, G. W., Bossart, P., & Blümling, P. (2004). Excavation disturbed zone (EDZ) in clay shale: Mont Terri. Mont Terri Technical Report, TR 01-01. Federal Office of Topography (swisstopo), Wabern, Switzerland. www.mont-terri.ch.
  29. Martin, C. D., Macciotta, R., Elwood, D., Lan, H., & Vietor T. (2011). Evaluation of the Mont Terri Mine-By response: Interpretation of results and observations. Report to Nagra (unpublished).Google Scholar
  30. Masset, O. (2006). Rock Laboratory pore pressure long term evolution. Mont Terri Technical Note, TN 2006-43. Federal Office of Topography (swisstopo), Wabern, Switzerland. www.mont-terri.ch.
  31. Mazurek, M. (1998). Mineralogical composition of Opalinus Clay at Mont Terri—A laboratory intercomparison. Mont Terri Technical Note, TN 98-41. Federal Office of Topography (swisstopo), Wabern, Switzerland. www.mont-terri.ch
  32. Mazurek, M., Hurford, A. J., & Leu, W. (2006). Unravelling the multi-stage burial history of the Swiss Molasse Basin: integration of apatite fission track, vitrinite reflectance and biomarker isomerisation analysis. Basin Research, 18, 27–50.Google Scholar
  33. Nagra (2002). Projekt Opalinuston. Synthese der geowissenschaftlichen Untersuchungsergebnisse. Nagra Technischer Bericht, 20-03. Nagra, Wettingen, Switzerland. www.nagra.ch.
  34. Neerdael, B., DeBruyn, D., Mair, R. J., & Taylor, R. N. (1999). Geotechnical behavior of Boom Clay. Commission of the European Communities. Nuclear Science and Technology, Pilot tests on radioactive waste disposal in underground facilities, EUR 13985, 223–238.Google Scholar
  35. Nussbaum, C., Bossart, P., Amann, F., & Aubourg, C. (2011). Analysis of tectonic structures and excavation induced fractures in Opalinus Clay, Mont Terri underground Rock Laboratory (Switzerland). Swiss Journal of Geoscience, 104(2), 187–210.Google Scholar
  36. Nussbaum, C., Kloppenburg, A., Caër, T., & Bossart, P. (2017). Tectonic evolution around the Mont Terri rock laboratory, northwestern Swiss Jura: constraints from kinematic forward modelling. Swiss Journal of Geosciences, 110.  https://doi.org/10.1007/s00015-016-0248-x (this issue).
  37. Pei, J. (2003). Effect of sample disturbance in Opalinus Clay shales. Ph.D. dissertation, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.Google Scholar
  38. Peron, H., Hueckel, T., Laloui, L., & Hu, L. B. (2009). Fundamentals of desiccation cracking of fine-grained soils: experimental characterization and mechanisms identification. Canadian Geotechnical Journal, 46, 7–1201.Google Scholar
  39. Popp, T., Salzer, K., & Minkley, W. (2008). Influence of bedding planes to EDZ-evolution and the coupled HM properties of Opalinus Clay. Physics and Chemistry of the Earth, 33, 374–387.Google Scholar
  40. Rummel, F., & Weber, U. (2004). RA experiment: rock mechanical testing and characterization on drillcores of boreholes BRA-1 and BRA-2. Mont Terri Technical Note, TN 2004-38. Federal Office of Topography (swisstopo), Wabern, Switzerland. www.mont-terri.ch.
  41. Schmertmann, J. H., & Osterberg, J. O. (1960). An experimental study of the development of cohesion and friction with axial strain in saturated cohesive soils. In Research Conference on Shear Strength of Cohesive Soils (pp. 643–694). American Society of Civil Engineers.Google Scholar
  42. Schnier, H., & Stührenberg, D. (2007). LT experiment: strength tests on cylindrical specimens, documentation and evaluation (Phases 8 & 9). Mont Terri Technical Report, TR 03-04. Federal Office of Topography (swisstopo), Wabern, Switzerland. www.montterri.ch.
  43. Skempton, A. W. (1954). The pore-pressure coefficients A and B. Géotechnique, 4(4), 143–147.Google Scholar
  44. Thoeny, R. (2014). Geomechanical analysis of excavation-induced rock mass behavior of faulted Opalinus Clay at the Mont Terri Underground Rock Laboratory (Switzerland). Ph.D. dissertation, Swiss Federal Institute of Technology, Zürich, Switzerland.Google Scholar
  45. Thury, M., & Bossart P. (1999). Mont Terri rock laboratory, results of the hydrogeological, geochemical and geotechnical experiments performed in 1996 and 1997. Landeshydrologie und -geologie, Geologischer Bericht No. 23. Federal Office of Topography (swisstopo), Wabern, Switzerland. www.mont-terri.ch.
  46. Van Loon, L. R., Soler, J. M., Müller, W., & Bradbury, M. H. (2004). Anisotropic diffusion in layered argillaceous rocks: a case study with Opalinus Clay. Environmental Science and Technology, 38, 5721–5728.Google Scholar
  47. Vietor, T., Armand, G., Nyonoya, S., Schuster, K., & Wieczorek, K. (2010). Excavation induced damage evolution during a mine-by experiment in Opalinus clay. In Proceedings of the 4th Int. Meeting on Clays in Natural & Engineered Barriers for Nuclear Waste Confinement, Nantes, France.Google Scholar
  48. Walter, P. (2015). Environmental degradation of Opalinus Clay with cyclic variations in relative humidity. Master thesis, Swiss Federal Institute of Technology, Zürich, Switzerland.Google Scholar
  49. Wild, K. M., Amann, F., & Martin, C. D. (2015a). Dilatancy of clay shales and its impact on pore pressure evolution and effective stress for different triaxial stress paths. In Proceedings of the 49th US Rock Mechanics/Geomechanics Symposium, American Rock Mechanics Association.Google Scholar
  50. Wild, K. M., Amann, F., & Martin, C. D. (2015b). Some fundamental hydromechanical processes relevant for understanding the pore pressure response around excavations in low permeable clay rocks. In Proceedings of the 13th International Congress of Rock Mechanics. International Society for Rock Mechanics.Google Scholar
  51. Wild, K. M., Wymann, L. P, Zimmer, S., Thoeny, R., & Amann, F. (2015c). Water retention characteristics and state-dependent mechanical and petro-physical properties of a clay shale. Rock Mechanics and Rock Engineering, 48, 427–439.Google Scholar
  52. Yong, S. (2007). A three-dimensional analysis of excavation-induced perturbations in the Opalinus Clay at the Mont Terri Rock Laboratory. Ph.D. dissertation, Swiss Federal Institute of Technology, Zürich, Switzerland.Google Scholar
  53. Yong, S., Kaiser, P. K., & Loew, S. (2010). Influence of tectonic shears on tunnel-induced fracturing. International Journal of Rock Mechanics and Mining Sciences, 47, 894–907.Google Scholar
  54. Yong, S., Kaiser, P. K., & Loew, S. (2013). Rock mass response ahead of an advancing face in faulted shale. International Journal of Rock Mechanics and Mining Sciences, 60, 301–311.Google Scholar

Copyright information

© Springer International Publishing AG 2018

Authors and Affiliations

  1. 1.Institute of Geology, Engineering GeologySwiss Federal Institute of Technology, ZurichZurichSwitzerland
  2. 2.Knight Piésold Ltd.,VancouverCanada
  3. 3.Grundwasserschutz und EntsorgungAF-Consult Switzerland AGBadenSwitzerland
  4. 4.Sektion Geologie (GEOL)Eidgenössisches Nuklear-Sicherheitsinspektorat (ENSI)BruggSwitzerland

Personalised recommendations