ABSTRACT
This chapter addresses the characterization and quantification of the first 'smaller-scale' set of Physical attributes in detail, and the effect each of them can have on the physical behavior of the joints. It introduces Geometrical Attributes without going into further detail about these larger-scale structural-geology attributes of rock masses, which determine modeled geometries with Universal Distinct Element Code (UDEC)- Mohr-Coulom (MC), UDEC- Barton-Bandis (BB) and 3DEC-MC. Rock discontinuities vary widely in terms of their origin and associated physical characteristics. An important subject that goes beyond the more common distinction that we make between constant normal stress and 'constant' normal stiffness shear testing of rock joints, is the correct transformation of stress. Rock masses may range from almost intact, through well jointed, to heavily crushed, due to increased proximity to fault zones. There have been various stages in the profession's acknowledgement of the need for scale-effect adjustment concerning the shear strength of rock joints.
