Localization of Shear in Water-Saturated Granular Media.

0508425 - ÚCHP 2020 DE eng C - Conference Paper (international conference)
Pařez, Stanislav - Trávníčková, Tereza - Goren, L. - Aharonov, E.
Localization of Shear in Water-Saturated Granular Media.
Book of Abstracts. Vol. Session 6. Postdam: Helmholtz Centre Potsdam German Research Centre for Geosciences - GFZ, 2019 - (Hofmann, H.; Spalek, A.), s. 78
[EURO-Conference on Rock Physics and Geomechanics /13./. Potsdam (DE), 02.09.2019-06.09.2019]
R&D Projects: GA ČR(CZ) GJ19-21114Y
Institutional support: RVO:67985858
Keywords : granular media * pore fluid * fault
OECD category: Geology

Slip on geological faults is localized within narrow shear bands in the gauge zone. Often, the shear bands are located at the boundary between the gauge and the damage zone. Using a recently developed multi-scale model to couple grain + fluid evolution, we study the location of shear bands within a well-drained gauge. While in dry granular lay- ers there is no preferred position of shear bands, we show that water-saturated systems tend to localize shear on their boundary under some conditions. The conditions favoring boundary localization are high shear velocity, gauge thickness and low gauge permeability and confining stress. We propose a scaling argument to describe the pressure deviations in a shear band, and use that to predict the conditions for shear localizations on the boundary.
Permanent Link: http://hdl.handle.net/11104/0304175