Continuous and discrete modeling of failure modes in geomechanics

摘要

After recalling briefly the main results obtained in the framework of the continuum mechanics by applying Hill's condition of stability to loose and dense sands, an analysis of grain avalanches by a discrete form of the second order work is proposed. It is shown some spatial and temporal correlations between the bursts of kinetic energy and the negative values of the discrete second order work. While localized modes of failure with shear band formation are well described by the vanishing values of the determinant of the acoustic tensor, it is conjectured in conclusion that diffuse modes of failure might be characterized by the vanishing values of the second order work (what corresponds for conventional elasto-plastic models to the vanishing values of the determinant of the symmetric part of the constitutive matrix).