Elastic moduli of a stratified rock mass

Abstract

It is postulated that the rock mass is divided by parallel bedding planes into homogeneous transversely isotropic layers of randomly varying thickness and properties. A. homogeneous, transversely isotropic and continuous medium is defined, the behaviour of which is equivalent, on a large scale, to the behaviour of the rock mass. The stresses and strains in this equivalent medium are volumetric averages, within a representative volume, of the corresponding components in the rock mass. The strain energies in the two media are equal. The five elastic moduli of the new medium are expressed in terms of the thickness and properties of the strata in the rock mass. It is shown, as an example of application, that the stratification increases the relative displacement of the roof and floor of tabular excavations, when the layers are isotropic and their Poisson's ratios are equal.