Brief communication: The influence of mica-rich rocks on the shear strength of ice-filled discontinuities

• Published in: The Cryosphere
• Main Authors: P. Mamot, S. Weber, M. Lanz, M. Krautblatter
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2020
• Subjects: Environmental sciences; GE1-350; Geology; QE1-996.5; Ice; permafrost; The Cryosphere
• Online Access: https://doi.org/10.5194/tc-14-1849-2020; https://doaj.org/article/e8c4ab3aa42c4eafb39af2b7ca22c5ca

A temperature- and stress-dependent failure criterion for ice-filled rock (limestone) joints was proposed in 2018 as an essential tool to assess and model the stability of degrading permafrost rock slopes. To test the applicability to other rock types, we conducted laboratory tests with mica schist and gneiss, which provide the maximum expected deviation of lithological effects on the shear strength due to strong negative surface charges affecting the rock–ice interface. Retesting 120 samples at temperatures from −10 to −0.5 ∘ C and normal stress of 100 to 400 kPa , we show that even for controversial rocks the failure criterion stays unaltered, suggesting that the failure criterion is transferable to mostly all rock types.