ABSTRACT
The concepts of stress and strain are fundamental to all aspects of geotechnical engineering and it is important to define some terms before discussing how these are used.
Force and load are synonymous and are expressed in the metric system in newtons (N) or multiples of newtons. For most rock mechanics applications, the units kilonewtons (103 N) and meganewtons (106 N) are appropriate at project scale; giganewtons (109 N) come into play where describing stiffness or deformability of rock.
