ABSTRACT
The paper deals with two kinds of shear asymmetry of layered rocks. The first kind is characterized by different mechanical behaviour and defined by different shear moduli and shear resistance of rocks when acted on by shear stresses in two opposite directions. It is shown that the rocks exhibit the maximum resistance to the pure shear when the principal compression is perpendicular to the layers and the principal tension is parallel to them. The second kind of shear asymmetry occurs at the boundaries of individual layers and is manifested by different conjugate perpendicular shear strains and stresses. This asymmetry is to some measure analogous to Cosserat phenomena. It is also shown how the orientation of layers with respect to the slope exerts the influence upon the stability.
