ABSTRACT
Metamorphic and sedimentary rocks exhibit anisotropy due to the complex mechanical, thermal and chemical processes taking place during their formation. The anisotropy of rocks is of great engineering interest and must be taken into account in planning of many engineering problems especially in dams, tunnels, foundations, radioactive repositories and petroleum engineering problems. Rocks composed of parallel layers (sedimentation or schistosity), e.g. schists, phyllites, shales, etc. belong to the so-called cross-anisotropic or transversely isotropic materials. In this paper the word cross-anisotropic will be used when referring to this kind of rocks.
