CONSTITUTIVE MODELING AND INSTABILITIES OF SOIL BEHAVIOR

In general, the notions of lack of stability and lack of uniqueness ar e not equivalent. This question is briefly discussed in the case of so il behaviour. By utilising an incrementally nonlinear model and variou s types of loading paths (i.e. proportional loading and with multiple bends) stability and uniqueness are more precisely investigated in the case of undrained paths on loose sands. The theoretical results are a lso analysed with respect to the convergency of the response curves wh en the length of bends decreases. It is then shown that some conclusio ns obtained in the case of undrained loading can be generalised for a large class of stress paths.