A Qualitative Stress-Strain (Time) Model for Soft Clays

Successful analytical modeling of the behavior of soils requires that these models incorporate the significant factors which control real soil behavior. To illustrate this point, a qualitative stress-strain (time) model for understanding the behavior of soft clays is described. The major feature of the model is the yield envelope—the locus of effective stress states in q–p stress space which result in a change from small strain response to loading to a large strain response. The model is used to provide a qualitative understanding of the behavior of soft clays subjected to embankment loading at two sites. Various features of the soil model, such as normalization of the yield envelope with respect to preconsolidation pressure together with use of strain energy as a parameter to define yield, are also discussed in relation to analytical formulation of the model.