Shear creep behaviour of soil–structure interfaces under thermal cyclic loading

The coupling effect of initial shear stress and thermal cycles on the thermomechanical behaviour of clay concrete and sand–concrete interfaces has been studied. A set of drained monotonic direct shear tests was conducted at the soil–concrete interface level. Samples were initially sheared to half of the material's shear strength and then they were subjected to five heating/cooling cycles before being sheared to failure. The test results showed that the effect of thermal cycles on the shear strength of the materials was negligible, yet shear displacement occurred during application of thermal cycles without an increase in shear stress, confirming the coupling between the shear stress and temperature. In addition, a slight increase of stiffness due to the coupling was observed which diminished with further shearing.