Use of critical state representations of sand in the method of stress characteristics

The limitations of critical state representations of sand behaviour are discussed and it is shown that stress dilatancy is an implicit part of a critical state framework. It is then argued that dilatancy leads to underestimates of bearing capacity factors in the method of characteristics. Kinematic constraints should also be considered in such calculations. Both dilatancy and kinematic constraint may be introduced into a stress characteristics approach while preserving critical state characterization of sand, using the technique known as the method of associated fields. Key words: bearing capacity, critical state, stress dilatancy, method of characteristics.