A theoretical framework for calibrating the transversely isotropic elastic rock parameters from UCS tests on cylindrical specimens using circumferential strain measurments

The standard method for determining the set of five independent elastic constants of transversely isotropic rocks relies on the conduction of at least three UCS tests with directional radial strain measurements on samples with varying isotropy plane orientation. However, in many cases only averaged values for the lateral strains are available from chain extensometer measurements as commonly carried out in rock mechanics laboratories. Such measurement setups disregard the anisotropic deformational behavior of transversely isotropic rock samples which appears as a result of non-horizontal isotropy plane orientations. A direct utilization of averaged radial strains in the determination of the five independent parameters without further considerations is thus not possible. In this paper a possible scheme for the inclusion of circumferential strain measurement information in the determination of the elastic constants of transversely isotropic rocks based on UCS tests carried out on three samples with varying isotropy plane inclinations is presented.