ABSTRACT
Anisotropic ground arises from parallel laminations within a rock mass, whether due to sedimentary bedding, joints or tectonic fabric. Anisotropy is both modulus and stress dependent (Chappell, 1989) and therefore not all rock masses with parallel structure or fabric will exhibit the same degree of anisotropic behaviour. Sedimentary and meta-sedimentary rocks are typically the first to be considered as laminated however, analogous flow behaviour can occur in igneous and metamorphic rocks creating laminations which behave similarly to sedimentary.
