Cam-Clay Predications of Undrained Strength

The validity of the critical-state Cam-Clay theory to predict undrained shear strength is substantiated with data from 96 different clay and silt soils reported in the geotechnical literature. The study investigates normally-consolidated and overconsolidated strengths, which is important in that a range of strengths is more common in natural soil deposits. Attention is given to establishing the critical-state pore pressure parameter from routine consolidated-undrained shear tests. The critical-state theory is shown to be an effective stress method that incorporates total stress approaches similar to SHANSEP.