Elastic energy and shear work

Based upon a suggestion by Schofield (personal communication) that elastic energy may be crucial to the meaningful interpretation of shear work during deformation, Thurairajah (1961) made detailed calculations of the energy components in an effectively stressed soil. His work with both drained and undrained tests on clays and sand led to remarkable observations. It was found that the rate of work dissipated in plastic deformation equals the product of the effective mean normal stress, p′, and M, the coefficient of friction at critical state, and that this result applied not only when paths reached critical states but at...