A laboratory study on the thermomechanical behaviour of clayey soils

Abstract

This paper presents the findings of a laboratory investigation of the thermomechanical behaviour of clayey soils. The tests were performed on reconstituted and natural clayey soils using triaxial cells modified to control temperature. The range of temperatures that were investigated is from 20° to 60°C. The thermal behaviour of the clays and the influence of temperature on their mechanical behaviour were investigated separately. The analysis of the experimental results obtained in drained and undrained nonisothermal tests and during thermal consolidation made it possible to identify a link between the thermal and the time-dependent behaviour of the soil skeleton. Therefore, as for creep processes, the response of the soil to thermal loading is not unique but among other factors depends strongly on the overall and recent stress history experienced by the soil. In the range of temperatures investigated, the deformability and strength of the soil were found to be relatively independent of temperature. Stiffening of the soil results from thermal cycles.Key words: clay, temperature, creep, stress history, recent stress history.