A thermomechanical model for saturated clays

A thermomechanical model for saturated clays is proposed within the framewo rk of recent extensions of the Cam-Clay model. The results of some tests fo und in the literature are analyzed, and the main features of the thermomech anical behaviour of clays are identified. The effect of the overconsolidati on ratio (OCR) on the volume change of a soil (expansion-contraction) submi tted to heating is well established using experimental data obtained for se lected soils by various authors. However, existing models need to be modifi ed to correctly model this feature. For this reason, a new volumetric therm al plastic mechanism is developed that allows for the prediction of plastic strains at higher OCR values. The overconsolidation effect observed when h eating a normally consolidated soil is also modelled. Particular attention is paid to the coupling and hardening phenomena related to the combined eff ects of stress and temperature. A qualitative validation is made by examini ng the response of the model under a given thermomechanical path. Compariso n with existing thermomechanical experimental results shows that the model can provide satisfactory predictions.