The Soft Soil Creep model distinguishes between primary loading and unloading/reloading behaviour and in this respect the model is similar to the Hardening Soil and Soft Soil models. In the last two models, the distinction is made by means of a cap, i.e. a curved plane in stress space that defines the limit stress state between those two modes of loading. The position of this cap is initially determined by the preconsolidation stress. However, in the Soft Soil Creep model, the position of the cap is not only determined by the maximum stress state that has been reached in the past, as is the case in the other two models, but it is also a function of time.
This serie of 3 articles also appeared in Plaxis Bulletin 15, Plaxis Bulletin 16 and Plaxis Bulletin 17.