″GEOTECHNICAL″ STRESS VARIABLES APPROACH TO CYCLIC BEHAVIOUR OF SOILS.
The paper presents a mathematical description of the memory of a material. In this framework the stress-strain constitutive law is written in terms of ″geotechnical″ stress variables, with which it is possible to take account of the logarithmic dependence of volumetric strain on the effective isotropic pressure, the pressure sensitivity of the material behavior in shear, and of shear compaction in cyclic loading. These variables are a generalization of multiaxial conditions employed in Cam Clay type models, i. e. the logarithm of the isotropic effective stress and the stress ratio. Refs.