Ring-shear test data of glass beads 200-300 µm used for analogue experiments in the tectonic modelling labs at GFZ Potsdam and the Institute of Geophysics of the Czech Academy of Science, Prague

Abstract

This dataset provides friction data from ring-shear tests on glass beads with a diameter of 200-300 µm used in analogue modelling of tectonic processes as a rock analogue for “weak” layers in the earth’s upper crust (e.g. Klinkmüller et al., 2016; Ritter et al., 2016; Lohrmann et al., 2003) or as “seismogenic” crust (Rudolf et al., 2022). The glass beads are characterized by means of internal friction coefficients µ and cohesion C.
According to our analysis the materials show a Mohr-Coulomb behaviour characterized by a linear failure envelope. Peak, dynamic and reactivation friction coefficients of the glass beads are µP = 0.51 , µD = 0.40, and µR = 0.44, respectively (Table 5). Cohesion of the material ranges between 40 Pa and 70 Pa. The material shows a minor rate-weakening of ~1% per ten-fold change in shear velocity v and a stick-slip behaviour at low shear velocities and at high loads.

Methods

The data presented here are derived by ring shear testing using a SCHULZE RST-01.pc (Schulze, 1994, 2003, 2008) at the Helmholtz Laboratory for Tectonic Modelling (HelTec) of the GFZ German Research Centre for Geosciences in Potsdam. The RST is specially designed to measure friction coefficients µ and cohesions C in loose granular material accurately at low confining pressures (<20 kPa) and shear velocities (<1 mm/sec) similar to sandbox experiments. In this tester, a granular bulk material layer is sheared internally at constant normal stress σN and shear velocity v while shear force and lid displacement (corresponding to density and volume change ΔV) are measured continuously. For more details see Klinkmüller et al. (2016) and Ritter et al. (2016).

Authors

• Rosenau, Matthias;GFZ German Research Centre for Geosciences, Potsdam, Germany
• Kemnitz, Helga;GFZ German Research Centre for Geosciences, Potsdam, Germany
• Pohlenz, Andre;GFZ German Research Centre for Geosciences, Potsdam, Germany
• Warsitzka, Michael;Institute of Geophysics, Czech Academy of Sciences, Prague, Czech Republic;Bundesgesellschaft für Endlagerung mbH (BGE), Peine, Germany
• Zavada, Prokop;Institute of Geophysics, Czech Academy of Sciences, Prague, Czech Republic

Contact

• Rosenau (Matthias) ; GFZ German Research Centre for Geosciences, Potsdam, Germany; ➦

Contributors

HelTec - Helmholtz Laboratory for Tectonic Modelling (GFZ German Research Centre for Geosciences, Germany); Rosenau

Keywords

EPOS, TCS MSL, analogue models of geologic processes, multi-scale laboratories, property data of analogue modelling materials, analogue modelling results, software tools, Cohesion, Friction coefficient, deformation > shearing, fault, Microspheres > Glassy, Ring-shear tester, Cohesion, Friction coefficient, Microspheres > Glassy, Ring-shear tester, deformation > shearing, fault