Influence of Temperature on the Volume Change Behavior of Saturated Sand

The effect of temperature on the volume change of sand is rarely reported but may be relevant to the performance of energy geostructures. This study involves an investigation of the thermal volume change behavior of saturated, dense sand through a series of temperature-controlled, isotropic hollow cylinder triaxial compression tests. Variables measured during a heating stage include the volume of water expelled from the sand specimen, the temperatures at the top, bottom, and inside of the specimen, and the axial and volumetric strains. The volumes were used along with thermo-elastic relationships for the pore water and soil skeleton to infer the axial and volumetric strains during drained heating. It was observed that the thermally induced axial and volumetric strains were negative, reflecting expansion. The pore water was observed to flow out of the sand specimen during heating, reflecting differential thermal expansion of the pore water and sand particles. The thermal volume changes were observed to be independent of the mean effective stress, as the dense sand specimens were all in normally consolidated conditions. Three linear equations incorporating the effects of temperature on the volume change behavior of dense sand were proposed and match well with the experimental data. The experimental approach proposed in this study can be used in the future to evaluate the role of sand density and stress state on the parameters of these equations.