EFFECTS OF TEMPERATURE ON EQUIVALENT ELASTIC AND CREEP DEFORMATION BEHAVIORS OF A DRIED SAND

Abstract

Granular materials, e.g., sand, may be subjected to changes in the ambient temperature while supporting typical working stress. As a result, their elastic and long-term creep deformation behaviors may be altered by the temperature change. In this study, an automated triaxial loading system that can accurately control both the loading and temperature histories was developed. A series of special triaxial compression tests using an air-dried sand sample was performed. The temperature surrounding the sample was varied from 30 oC to 60 oC and controlled constant for subsequent shearing by axial compression. The shearing was performed using various loading histories consisting of: i) continuous monotonic loading (ML); ii) sustained (creep) loading (SL); and iii) cyclic loading (CL) with small amplitude. The following are found from the results of this study. The peak and residual shear strengths tend to decrease with increasing temperature. The equivalent elastic Young’s modulus increases with increasing stress level in a hypo-elasticity manner, but at the same stress level, it decreases significantly with increasing temperature. Creep strain is obvious and it increases with increasing stress level and temperature.