A THREE-DIMENSIONAL STRESS-STRAIN MODEL OF SAND UNDERGOING CYCLIC ROTATION OF PRINCIPAL STRESS AXES

摘要

A new three-dimensional stress-strain model of sand is proposed by using the concept of multiple shear mechanisms which previously has been developed in a two-dimensional manner. The original model exhibited excellent capability for simulating the principal stress axis rotation. By extending this approach with a new dilatancy model, the present model makes it possible to describe a general stress state in three-dimensional space with the whole six degrees-of-freedom of stress taken into account. Modelling of sand behaviours under general drained and undrained conditions was achieved by applying a stress-dilatancy relation to all individual shear mechanisms. It was demonstrated that the model predicts well soil behaviour in rather complex three-dimensional shear loadings as well as in more fundamental two-dimensional ones.