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

Abstract

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°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.