Abstract: | The paper outlines the theory of generalized plasticity in which yield and plastic potential surfaces need not be explicitly defined, and shows how a very effective general model describing the behaviour of sands and of clays under monotonic or transient loading can be developed. The model is currently one of the simplest and yet one of the most effective ones for describing the full range of behaviour. The hierarchical structure of the model limits the number of parameters which have to be experimentally determined for a given material to those strictly necessary for the problem at hand. A discussion of currently used models is included. |