Prediction of triaxial stress-strain behaviour of Winnipeg clay using an anisotropic elastic-plastic model

An anisotropic elastic-plastic model has been used to examine measured properties of plastic Lake Agassiz clay from Winnipeg. Anisotropy produces linear (elastic) undrained behaviour, even in normally consolidated specimens. Comparisons are made between predicted and measured values of Δu/Δp and Δεv/Δε1 in the elastic range. It is shown that the shapes of yield loci and the corresponding p′, V-traces can be generated assuming (1) an elliptical normalized state boundary surface, and (2) anisotropic elasticity. Differences between this model and modified Cam-Clay lie in the anisotropy of the elasticity, and not in the shape of the state boundary surface.