1. General

1.1 Rock classification

The distinction between rock and soil is essentially based on the cohesion of the material. These cohesive forces are generally weaker in a soil that includes granular, non-cemented materials and cohesive clayey materials. A rock is conventionally distinguished from a soil by a uniaxial compressive strength threshold of 1 MPa. Rocks are also less deformable and less permeable than soils.

Rocks are classified into three main categories according to their origin, then sub-classified according to their composition, structure and texture...