Experimental and numerical analyses of the thermo-mechanical stability of an embankment with shady and sunny slopes in a permafrost region

The hydro-thermo-mechanical state is important for embankments in permafrost regions, especially for the embankments with shady and sunny slopes. It is difficult to determine the state because the complex hydro-thermo-mechanical interaction usually occurs within the embankments during freezing-thawing processes. To explore the thermo-mechanical stability of embankments in permafrost regions, an in-situ experiment of highway with asphalt pavement was performed firstly. Based on the observed results, a mathematical model was developed to describe the hydro-thermo-mechanical process. Subsequently, the model was validated by the observed data. Finally, the long-term stability of the embankment was analyzed and predicted with a climate warming rate of 0.052 degrees C/a. The results show that, (1) the asphalt pavement heat absorption effect and shady-sunny slope effect reduce the stability of the embankment; (2) the deformation of the embankment demonstrates the periodic freezing-thawing fluctuation and the long-term creep settlement characteristics; (3) the settlement is mainly caused by the freezing-thawing behavior of the active layer, the moving down of the permafrost table, and the warming of permafrost; (4) the shady-sunny slope effect induces the uneven settlement, and the settlement difference increases with operation time. The study will be helpful for the design and maintenance of embankments in permafrost regions. (C) 2017 Elsevier Ltd. All rights reserved.