Thermally induced deformation of soils: A critical overview of phenomena, challenges and opportunities

Soils are continuously subjected to thermal loads – and thus to temperature variations – as a consequence of natural or anthropogenic perturbations that involve the transfer of heat. For example, several engineering applications exist in which soils undergo temperature variations over time scales that can vary and last from seconds to centuries. As temperature variations can critically influence the properties and behavior of soils, and consequently the performance of many engineering applications, the understanding of the response of such materials to thermal loads has warranted important scientific investigations over the past fifty years. Nevertheless, various fundamental questions remain unresolved regarding the response of soils subjected to thermal loads, particularly the thermally induced deformation of such materials. In this context, this paper presents a critical overview of compelling phenomena, challenges and opportunities which accompany the thermally induced deformation of soils. Through an analysis of distinguishing and contradicting phenomena characterizing the deformation of both fine-grained soils (e.g., clays and silts) and coarse-grained soils (e.g., sands) subjected to thermal loads, this study discusses various unresolved challenges and highlights scientific breakthroughs and engineering opportunities that can result from the expansion of current knowledge in this scope.