Temperature effects on the elastic and time-dependent deformation behaviours of Hostun sand under triaxial shearing

Long-term deformation of geomaterials is related to the time effects, which is consisting of the following two
components: i) loading rate effect; and ii) ageing effect. Nowadays, the number of temperature-related geotechnical engineering projects tends to increase, e.g., energy pile, heating and cooling via borehole heat exchangers, etc. Therefore, thermo-mechanical behaviour should be investigated for the long-term deformation problems. For recent years, the thermomechanical behaviour of cohesive soils has been revealed by various studies, while there are limited studies regarding the thermal effects in granular materials such as sand. This research performed a series of special drained triaxial compression tests on Hostun sand, which is widely used in the field of geotechnical engineering research. The cyclic loading (CL) and sustained loading (SL) were performed to evaluate the quasi-elastic Young’s modulus and creep behaviour at different temperatures. The target temperatures consist of 30, 45, and 60 °C. The results show that: i) the elastic Young’s modulus is stress level-dependent, which is of a hypo-elastic type; ii) the elastic Young’s modulus decreases with an increase in the temperature; and iii) the creep strain increases with increasing temperature and stress level.