Study on fine soil behaviour in function of temperature in the context of climate change

One of the expected effects of global warming is the gradual melting of permafrost. Its melting will significantly impact soil material properties, potentially causing instability of infrastructures and triggering natural hazards. The objective of this experimentation is to quantify the effect of thawing on the geomechanical strength of a reconstituted fine soil. More specifically, it is intended to qualify the initial frozen state and compare it to the state after thawing. This study was carried out in three steps. To begin, soil samples were identified by the usual parameters. Then, artificial samples were sheared at a temperature of –5°C in our temperature controlled triaxial press in order to determine the soil’s parameters. Finally, identical tests were carried out at a temperature of +5°C in order to thaw the soil completely before the shearing. In total, three tests for each temperature were compared and discussed. The expected results aim at a better understanding and quantification of soil strength reduction after the thawing phase. As many infrastructures are now built on permafrost, such as infrastructures, or alpine chalets, they will be affected by this phenomenon in the near future. A better understanding of (geo)mechanical consequences might facilitate risk analysis, evaluation and mitigation