An Experimental Method to Determine the Elastic Properties of Transversely Isotropic Rocks by a Single Triaxial Test

A novel method is proposed for determining the deformation anisotropy of rocks by a single triaxial test using a single specimen sampled from an arbitrary direction. Transversely isotropic elasticity is assumed for the purpose of application of the test method to sedimentary and metamorphic rocks, and the non-axial symmetric stress–strain relationships of anisotropic rocks are determined by triaxial testing by means of a simple improvement to the cap in the triaxial testing apparatus. Both the elastic parameters and the directions of the transversely isotropic elasticity can be obtained by measuring the shear deformations that occur under triaxial stress conditions. An overview of the method for determining transversely isotropic elasticity is presented in this paper, along with the results of a sensitivity analysis performed assuming simulated strains with random measurement errors. The results show that the directions of anisotropy can be determined precisely using the directions of the principal strains measured during isotropic compression and that the elastic parameters can be determined uniquely from the stress–strain relationships observed during both the isotropic and axial compression processes.