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 aniso tropic 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 transv erse isotropic solid under axisymmetric loading conditions. Use of thi n walled hollow cylindrical specimens instrumented with tangential str ain gages on both the inner and outer surfaces allows one to completel y define the average strains in the cylinder wall. Testing of a single specimen under axial and radial loading conditions is sufficient to d etermine the variation of the material elastic ''constants'' as a func tion of the applied stresses. Results are presented for two very diffe rent rock types, and illustrate the consistency of the developed metho dology.