  We propose a phase-field model of shear fractures using the deviatoric stress
decomposition (DSD). This choice allows us to use general three-dimensional
Mohr-Coulomb's (MC) failure function for formulating the relations and
evaluating peak and residual stresses. We apply the model to a few benchmark
problems of shear fracture and strain localization and report remarkable
performance. Our model is able to capture conjugate failure modes under biaxial
compression test and for the slope stability problem, a challenging task for
most models of geomechanics.
