Experimental investigation on the thermal stability and deformation behavior of a novel duct-ventilated embankment in a snowy permafrost region

Abstract

Permafrost degradation threatens the stability of infrastructure in cold regions, driven by climate warming and increasing human activity. In snowy permafrost regions, the insulating effect of snow cover exacerbates this issue by limiting the heat dissipation from the ground. To mitigate this problem, we developed a novel duct-ventilated embankment system incorporating bent ventilation ducts, temperature-controlled dampers, and vent caps. The design and experimental setup were based on similarity criteria and numerical simulations to accurately replicate thermal and fluid dynamics in a scaled model. Using an environmental modeling system, we evaluated temperature distribution, air velocity in the ducts, and embankment deformation over seven freeze-thaw cycles. Results indicate that the soil beneath the slope of the unprotected embankment remained insufficiently frozen, with temperatures around −0.5 °C. In contrast, the duct-ventilated embankment lowered sub-slope soil temperatures to −1.5 °C by introducing cold air through the ducts. The enhanced design, which utilized vent caps, further reduced soil temperatures to −2 °C by the seventh cycle. The novel embankment also exhibited more pronounced frost heave, futher confirming the effectiveness of the ventilation system. This study offers valuable insights for improving the stability of infrastructure in snowy permafrost regions by mitigating permafrost degradation.