Stress-dependent irreversible volumetric contraction of sand due to thermal cycles

The intrinsic behaviour of dense sand under cyclic thermal loading at multiple stress levels, especially in the context of geostructures, is limited. This study uses a temperature-controlled triaxial cell to investigate the influence of cyclic thermal loading on the deformation of saturated Fontainebleau sand under constant isotropic confining pressure conditions. Soil specimens with an initial relative density of approximately 90% were consolidated under isotropic pressure of 15, 100, 200, 300, 400 or 500 kPa and then subjected to ten thermal cycles in the temperature range of 12°C–45°C. The results indicated that imposing heating–cooling cycles to dense sand resulted in irreversible compressive strain below the yield surface, accumulating at a reducing rate as the number of thermal cycles increased. The greater irreversible strain was observed under higher pressures, while the linear thermal expansion coefficient remained unchanged.