THE USE OF A VARIABLE SHEAR MODULUS IN ELASTIC-PLASTIC MODELS FOR CLAYS

Abstract When modelling the elastic behaviour of a clay it is often convenient to use a shear modulus which is proportional to the mean effective stress, in order to improve the accuracy of modelling. This choice can lead, however, to theoretical difficulties, in that the elastic behaviour may be non-conservative. These difficulties may be reflected as inaccuracies in calculations, particularly if cyclic loading is involved. A framework within which a pressure dependent shear modulus can be accomodated in a theoretically acceptable manner is described. Some experimental evidence for the variation of shear modulus with pressure is also discussed.