Heat-moisture-deformation coupled processes of a canal with a berm in seasonally frozen regions

Abstract

Over 60% of canals suffer frost heaving damage in seasonally frozen regions, which serious affected their drainage function. Especially for canals with berms, the problem gets worse. Due to special geometric characteristics, heterogeneous soil composition, irregular water supply and periodic freeze-thaw cycles, the heat-moisture-deformation processes involved in berms are more complex, and berm parts are more vulnerable to frost heaving damage in seasonally frozen regions, which threatens normal operation of canals. To investigate the mechanisms of frost heaving damage for a canal with berms, we established a heat-moisture-deformation coupled simulated model. A canal with a berm in seasonally frozen regions was taken as an example. The heat-moisture-deformation coupled processes and the frost heaving damage mechanisms of the canal with a berm were then analyzed. The results show that the temperature gradient of the berm is larger than that of other parts of the canal. At the end of the thawing process, the frozen core still exists in the berm. The large variation in moisture brings about large frost forces and generates frost erosion damage to the berm. In addition, the deformation at the leading edge of the berm is the largest, and the leading edge of the berm is the easily damaged area. The simulated results in this study contribute to understand the frost heaving mechanism of berms and provide a reference for further research on similar engineering in cold regions.