A CONCEPTUAL-MODEL FOR CLAY SOILS SUBJECTED TO NEGATIVE PORE-WATER PRESSURES

Understanding and predicting the volume change behaviour of soils subj ected to negative pore-water pressures presents a complex problem that requires a sound theoretical model matched to experimental evidence. A complete model must cover both saturated and unsaturated behaviour a nd relate stress levels to pore-water pressures and volume changes. A conceptual model for clay soils is presented which employs the princip les of critical state soil mechanics. In developing the model, conside ration is given to negative pore-water pressures arising as a result o f the independent response to reductions in water content and reductio ns in confining stresses. In this way the limits of the conceptual mod el are defined.