Shear-Rate-Dependent Behavior of Clayey Bimaterial Interfaces at Landslide Stress Levels
Abstract
The behavior of reactivated and first-failure landslides after large displacements is controlled by the available shear resistance in a shear zone and/or along slip surfaces, such as a soil-bedrock interface. Among the factors influencing the resistance parameter, the dependence on the shear rate can trigger catastrophic evolution (rate-weakening) or exert a slow-down feedback (rate-strengthening) upon stress perturbation. We present ring-shear test results, performed under various normal stresses and shear rates, on clayey soils from a landslide shear zone, on its parent lithology and other lithologies, and on clay-rock interface samples. We find that depending on the materials in contact, the normal stress, and the stress history, the shear-rate-dependent behaviors differ. We discuss possible models and underlying mechanisms for the time-dependent behavior of landslides in clay soils.
- Publication:
-
Geophysical Research Letters
- Pub Date:
- January 2018
- DOI:
- 10.1002/2017GL076214
- Bibcode:
- 2018GeoRL..45..766S
- Keywords:
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- landslide;
- ring shear;
- shear-rate-dependent;
- interface