A Dilatancy Constitutive Modelling of Saturated Sands Based on the State Parameter

A bounding-surface model is modified and introduced a state parameterbased on phase transformation state, e.g., when subjected to shear, sand will contract until phase transformation is reached, while, then dilatant until the ultimate where =constants simultaneously. With state parameter the deformation tendency of a sand at any time or any conditions can be judged correctly. As a result the dilatancy depends on the state in a way that yields a zero value at phase transformation state. This dependence allows a realistic modelling of the response of a sand in either loose or dense state, or in the transition from one state to another state. A comparison between model simulations and a sequence of experimental results for drained, monotonic loading conditions shows that the proposed concept and modelling technique work effectively using a unique set of parameters (or parameter dependence) for a given sand.