... Abstract Volumetric strains during triaxial tests of 44 sandstone materials were analysed in order to understand the physics of dilation. The samples originate from different North-Sea fields, and the porosities vary from 1 to 39 percent. Different confining stresses were applied to the same...

... measurements are sensitive to dilatancy which appears later in the damage process of the studied limestone. P.187 propagation damage process catholique reservoir characterization engineering amplitude variation porosity anisotropy diagram upstream oil & gas quality factor ultrasonic...

... for the detection of the localization in the hardening regime. But for a strong dilatant material such as Fontainebleau sandstone, the non-associativity is no longer sufficient. Non coaxial flow theory needs to be added to the constitutive law to have bifurcation consistent with data provided by careful experiments...