Prediction of Excess Pore Water Pressure during Undrained Heating of Clays

This paper focuses on the prediction of thermally-induced excess pore water pressure generation in saturated clays during undrained heating. This study involves an analysis of experimental data presented in the literature for normally consolidated clays with different mineralogical compositions. In these studies, the clays were heated under isotropic conditions from room temperature to a maximum change in temperature of 80 degrees C using thermal triaxial cells. The magnitude of thermally-induced excess pore water pressure was observed to depend on the porosity, the thermal coefficient of cubical expansion of the soil particles, the change in temperature, the compressibility of the soil skeleton, and the physico-chemical coefficient of structural volume change. A relationship between the physicochemical coefficient of structural volume change and the plasticity index of the clay was proposed in order to define an empirical model that can be used to predict the thermally-induced excess pore water pressure for saturated soils in general.