2-D localization analysis of saturated porous media

摘要

Conditions for localisation of deformation into a planar shear band in the incremental response of elastic-plastic saturated porous media are studied in the case of small strains and rotations. The critical modulus for localisation of both undrained and drained conditions are given in terms of the discontinuous bifurcation analysis. Further loss of uniqueness of the response of the coupled problem is investigated by means of positiveness of the second order work density. As an example, the critical hardening moduli and shear band angle for localisation are derived for the case of generalised plasticity. Quantitative results are given for different sands, characterised by appropriate material parameters of the Pastor Zienkiewicz model.