Coupled evolution of damage and porosity in poroelastic media: theory and applications to deformation of porous rocks

• DOI: 10.1111/j.1365-246x.2004.02172.x
• Publication Date: 2004-02-23T16:43:57Z
• Authors: Y. Hamiel; V. Lyakhovsky; A. Agnon
• Keywords: Poromechanics

SUMMARY We address the gradual transition from brittle failure to cataclastic flow under increasing pressures by a new model, incorporating damage rheology with Biot’s poroelasticity. Deformation of porous rocks is associated growth two classes internal flaws, namely cracks and pores. Cracks act as stress concentrations promoting failure, whereas pores dissipate leading distributed deformation. The present analysis, based on thermodynamic principles, leads system coupled kinetic equations for evolution along porosity. Each equation represents competition between cracking irreversible porosity change. In addition, model correctly predicts modes strain localization such dilating versus compacting shear bands. also reproduces dilatancy related change fluid pressure undrained conditions. For triaxial compression loading, when taken into consideration, first increases then decreases, after onset damage. These predictions are in agreement experimental observations sandstones. development provides an internally consistent framework simulating fracturing variety practical geological engineering problems nucleation deformation features poroelastic media during seismic cycle.