Moisture-temperature changes and freeze-thaw hazards on a canal in seasonally frozen regions

Freeze-thaw action is a complex moisture-heat-mechanics interaction process, which has caused prevailing and severe damages to canals in seasonally frozen regions. Up to now, the detailed frost damage mechanism has not been well disclosed. To explore the freeze-thaw damage mechanism of the canal in cold regions, a numerical moisture-heat-mechanics model is established and corresponding computer program is written. Then, a representative canal in the northeast of China is taken as an example to simulate the freeze-thaw damage process. Meanwhile, the robustness of the numerical model and program is tested by some in situ data. Lastly, the numerical results show that there are dramatic water migration and redistribution in the seasonal freeze-thaw variation layer, causing repetitive frost heave and thaw settlement, and tension-compression stresses. Therefore, the strengths of soil are reduced after several freeze-thaw cycles. Further, the heavy denudation damage and downslope movement of the canal slope would be quite likely triggered in seasonally frozen regions. These zones should be monitored closely to ensure safe operation. As a preliminary study, the numerical model and results in this paper may be a reference for design, maintenance, and research on other canals in seasonally frozen regions.