Anisotropic elasticity and yielding of a natural plastic clay

Simple elastic-hardening plastic constitutive models for soils can be very powerful for bringing together apparently unrelated observations of soil behavior and for predicting the response of geotechnical structures. The model known as modified Cam clay has been widely used for many years, but when yield loci for undisturbed natural soils are studied, it is found to be deficient in the shape of the yield locus that it assumes. However, the framework of critical state soil mechanics, within which the Cam clay model is constructed, can be used to generate anisotropic elastic-plastic constitutive models for soil which match experimental observations more closely.