ABSTRACT
This paper deals with progressive failure as a result of strain softening material behavior. Strain softening is in this context defined as loss of strength when a material is sheared beyond a peak value. For soft sensitive clays this behavior is not only a rheological phenomenon. Such materials are relatively loosely packed and when sheared the behavior will tend to be contractant. If the shearing occurs under undrained conditions there is no possibility of volume change and the contractant behavior induces excess pore pressures. Following the principle of effective stresses this implies that the contact forces between the soil grains is reduced and the shear strength of the soil is decreasing toward a residual value (see Figure 2).
