Shear banding modelling in cross-anisotropic rocks

Abstract

Sedimentary geomaterials such as rocks frequently exhibit cross-anisotropic properties and their behaviour depends on the direction of loading with respect to their microstructure. As far as material rupture is concerned, localised deformation in shear band mode appears generally before cracks and material failure. cavation fractured zone that develops around a gallery is strongly influenced by the material anisotropy.

Modelling the influence of strain localisation and viscosity on the behaviour of underground drifts drilled in claystone

“…7 requires additional compression experiments. Based on uniaxial compression results, an evolution of the cohesion of the Callovo-Oxfordian claystone with the loading orientation is proposed in [5]. The cohesion evolves according to Fig.…”

“…The strain localisation develops preferentially in the horizontal direction. This strain localisation development is governed by the cross-anisotropic plastic mechanical characteristics of the claystone [5].…”

“…This approach is chosen because shear banding is usually observed in geomaterials and develops before localised rupture or fractures [4]. Furthermore, the fracturing process in the Callovo-Oxfordian claystone is dominated by shear 40 fractures around the galleries [2]; thus, shear banding can be an adequate manner to represent these fractures [5].…”

“…However, this information is rarely available for rocks especially for large-scale problems. Qualitative comparison between numerical and experimental results of compression test that involve shear bands in the Callovo-Oxfordian claystone are available in [39,5]. The second gradient mechanical law of Eq.…”

“…Hereafter, it is proposed to A modelling of the EDZ with shear banding in the Callovo-Oxfordian claystone has been performed in [5]. The numerical results highlight how the ma-…”