Time-dependent thermal impact of asphalt pavement construction on duct-ventilated embankments in permafrost regions

• Evaluates the optimal construction interval before asphalt paving on ventilated embankments. • Reveals how asphalt paving timing affects permafrost thermal stability and duct efficiency. • Identifies heat transfer mechanisms and cooling attenuation at different embankment zones. • Provides engineering guidance for asphalt paving schedules in permafrost regions. Duct-ventilated embankment (DVE) technology are a widely used active cooling technique for stabilizing road engineering in permafrost regions. The strong heat-absorption effect of asphalt pavement can impact the DVE’s cooling function, especially at the side-slope foots, and then trigger severe thawing distress. The impact of asphalt pavement construction on DVE cooling performance is investigated in this work by using field experiments and numerical simulations on the Qinghai-Tibet Plateau (QTP). The results indicate that asphalt pavement significantly reduces the cooling efficiency of DVEs by increasing embankment temperatures and disrupting thermal stability, leading to permafrost degradation. Field data showed that after asphalt paving, the embankment’s lowest and highest temperatures increased by 4.7°C and 4.3°C at the embankment’s bottom center, respectively, while the permafrost table declined by 0.32 m in the first year. To simulate the thermal behavior of DVE under different construction intervals between DVE and asphalt pavement, a mathematical model was proposed. Simulations demonstrated that longer intervals enhance DVE’s cooling capacity, reducing peak temperatures and stabilizing the permafrost table compared to scenarios with no intervals. The thermal disturbance from asphalt pavement was most pronounced in the first four years, after which its influence diminished. The study concludes that optimizing the construction interval between embankment and asphalt pavement is key to preserving DVE’s cooling efficiency. A recommended interval of 36 months is proposed to mitigate thermal disturbances and ensure long-term embankment stability in permafrost regions. These findings have significant implications for engineering practices in permafrost regions, underscoring the importance of phased construction to maintain permafrost thermal stability. This study highlights the role of DVEs as active energy management systems that convert, store, and redistribute thermal energy through coupled conductive and convective processes. The findings provide new insights into optimizing energy transfer efficiency and thermal regulation strategies in cold-region infrastructures.