The importance of stress percolation to ductile deformation and shear localization in rocks
posterposted on 2020-07-20, 19:23 authored by Pamela Burnley
This poster describes a 2D FE study showing that stress transmission in rocks can be described as a percolation problem producing substantial stress modulations within a rock. With increasing load, the modulations in stress states create small widely distributed regions that yield well before the bulk of the rock has reached the yield criterion. Percolation of yielded regions leads to shear localization. Whether the shear localization remains cryptic or leads to large offsets, is a function of the density and distribution of yield nuclei. In addition, the presence of modulations in the stress state within a rock has many implications for understanding the rock’s other physical and chemical responses to stress. These results are consistent with the well documented observation of similar phenomena (force chains and shear localization) in granular materials and should be relevant to all geo-materials from poorly cemented sediments to fully dense crystalline rocks.