Pore water pressure prediction for undrained heating of soils

Abstract

This paper focuses on the validation of a prediction model for the thermally induced excess pore water pressure generated in saturated soils during undrained heating. A thermoelastic analysis was calibrated using experimental data presented in the literature for normally consolidated soils having different mineralogical compositions. The magnitude of thermally induced excess pore water pressure for these soils was observed to depend on the initial void ratio, the initial effective stress, the thermal coefficient of cubical expansion of the soil particles, the change in temperature, the compressibility of the soil skeleton and the physicochemical coefficient of structural volume change. An empirical relationship between the physicochemical coefficient of structural volume change and the plasticity index was proposed to predict the thermally induced excess pore water pressure for saturated, normally consolidated soils. To validate the model, an undrained heating test was performed independently on a specimen of normally consolidated kaolinite clay, and the measured thermally induced excess pore water pressures were found to match well with the model predictions.