Undrained Creep Behaviour of a Coastal Organic Silty Clay

Synopsis Stress controlled laboratory test data on the creep behaviour of a coastal organic silty clay under undrained conditions at different isotropic consolidation pressures and stress levels are reported. During undrained creep the sustained deviator stress was maintained at 90, 70, 50 and 30% of the ultimate deviator stress determined in normal strength tests. The pore pressures developed during creep have been shown to be due both to the distortional stress and also to the secondary compression effect. It is considered that any theory developed for the prediction of stress paths for undrained strength and creep behaviour of sensitive soils should take into account the pore pressures developed during secondary compression under zero deviator stress. The magnitude of pore-water pressure build-up during secondary compression is shown to be time and structure dependent. On donne les resultats d'essais au laboratoire, sous contrainte controlee, sur la tendance au fluage d'ne argile limonique organique co...