ON THE DETERMINATION OF ELASTIC-MATERIAL PARAMETERS OF TRANSVERSE ISOTROPIC ROCKS FROM A SINGLE TEST SPECIMEN

The determination of material parameters for rocks which display anisotropic behaviour has become more important in light of the development of powerful and economical analytical modeling techniques. The study presented herein is based on a testing framework aimed at determining the material parameters required to describe the behaviour of a transverse isotropic solid under axisymmetric loading conditions. Use of thin walled hollow cylindrical specimens instrumented with tangential strain gages on both the inner and outer surfaces allows one to completely define the average strains in the cylinder wall. Testing of a single specimen under axial and radial loading conditions is sufficient to determine the variation of the material elastic ''constants'' as a function of the applied stresses. Results are presented for two very different rock types, and illustrate the consistency of the developed methodology.