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High-resolution mini-seismic methods applied in the Mont Terri rock laboratory (Switzerland)

  • Kristof Schuster
  • Florian Amann
  • Salina Yong
  • Paul Bossart
  • Peter Connolly
Chapter
Part of the Swiss Journal of Geosciences Supplement book series (SWISSGEO, volume 5)

Abstract

We present several mini-seismic methods developed and applied in recent years in the Mont Terri rock laboratory. All these applications aimed at correlating and interpreting seismically derived parameters with relevant rock-mechanical parameters and findings. The complexity of the local site setting always required very high spatial and parameter resolution. Both, seismic P- and S-wave velocities and dynamic elastic parameters, such as the dynamic Poisson’s ratio ʋdyn and the Young’s modulus Edyn, are used to characterise the Opalinus Clay under real in situ conditions. We were able to establish a correlation between static and dynamic elastic Young’s moduli. We describe the extremely large, small-scale variability of seismic parameters normal and parallel to the bedding plane orientation and address the question of fracture detection. We also present examples of the characterization of excavation-damaged zones with seismic parameters, including extent as well as degree of damage, and compare these to geological and structural mapping. The evolution of borehole-disturbed zones (BdZ) was deduced from repeating high-resolution borehole measurements. Finally, we quantify seismic anisotropy at dimensions between several cm and tens of m.

Keywords

Seismic velocities Dynamic and static elastic parameters Seismic anisotropy Fracture detection EDZ BdZ Opalinus Clay Nuclear waste disposal 

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Notes

Acknowledgements

Over the years many colleagues participated in development and measurements. Many thanks to (in alphabetical order): Hendrik Albers, Hans-Joachim Alheid, Dieter Böddener, Christoph Czora, Werner Hökendorff, Peter Eichhorn, Friedhelm Schulte, Wilfried Stille and Torsten Tietz. We thank colleagues from swisstopo, Christophe Nussbaum, David Jaeggi, Thierry Theurillat and Senecio Schefer, for their straightforward local site support. We also thank both reviewers, Till Popp (IFG Leipzig) and Pierre Dick (IRSN Fontenay-aux-Roses), for their very helpful concerted comments that improved the paper. Roy Freeman reviewed the English for readability. Research leading to the results presented here has received funding from the German Federal Ministry of Economics and Energy.

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Copyright information

© Springer International Publishing AG 2018

Authors and Affiliations

  • Kristof Schuster
    • 1
  • Florian Amann
    • 2
  • Salina Yong
    • 2
    • 3
  • Paul Bossart
    • 4
  • Peter Connolly
    • 5
  1. 1.Federal Institute for Geosciences and Natural Resources BGRHannoverGermany
  2. 2.Earth Science DepartmentSwiss Federal Institute of TechnologyZurichSwitzerland
  3. 3.Knight Piésold Ltd.,VancouverCanada
  4. 4.Federal Office of Topography SwisstopoWabernSwitzerland
  5. 5.Rock Mechanics TeamCHEVRON, Chevron Exploration Technology CompanyHoustonUSA

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