ABSTRACT
Progressive failure in natural slopes of sensitive clays is a challenging topic that many researchers have dealt with during the last decades (Bernander 1978). In Scandinavia and in some regions around Quebec, Canada, large areas of clay is so sensitive that they may completely liquefy when remoulded. These clays are called quick clays. Examples of well-known dramatic slides in quick clays are the Norwegian retrogressive slides of Verdal (1893) and Rissa (1978). In a consolidated undrained triaxial test the quick clays exhibit a peak strength where after the soil structure collapses leading to increased pore water pressure and a corresponding reduction in effective stress. The gradual loss of strength for increasing strain is called strain softening.
