In geotechnical engineering, a discontinuity (often referred to as a joint) is a plane or surface that marks a change in physical or chemical characteristics in a soil or rock mass.
A discontinuity can be, for example, a bedding, schistosity, foliation, joint, cleavage, fracture, fissure, crack, or fault plane.
The orientations of discontinuities with the same origin are related to the process that has created them and to the geological history of the rock mass.
), the orientation, spacing, and the mechanical characteristics (shear strength, roughness, infill material, etc.)
Various international standards exist to describe and characterize discontinuities in geomechanical terms, such as ISO 14689-1:2003[9] and ISRM.