Pore Pressure Diffusion in Some Rock Mechanics Experiments

Non-homogeneity of the pore pressure field is an issue when testing low permeability geomaterials, as in the case of the Callovo Oxfordian claystone (k < 10(-19) m(2)), a possible host rock for radioactive waste disposal. Excess pore pressure can result in significant errors in the measured material parameters. An analytical solution for the pore pressure field evolution in a sample under various loading paths with different loading rates is presented. These solutions permit an estimation of the necessary testing procedures and applicable measurement corrections for reliable evaluation of poroelastic material properties. The proposed methods are applied in a parameter study on the Callovo Oxfordian claystone.