Wang Tianyu, Yan Li-E
College of Civil Engineering and Architecture, Guangxi University, 100 University Road, Nanning, 530004, Guangxi, China.
The Key Laboratory of Disaster Prevention and Structural Safety of Ministry of Education, Guangxi University, Nanning, 530004, China.
Sci Rep. 2022 Aug 2;12(1):13295. doi: 10.1038/s41598-022-17529-w.
Building roads in permafrost region is challenged because permafrost is sensitive to temperature increase. As an embankment gains/drains heat mostly at the upper surface, accurately modeling the heat transfer in the upper surface is crucial to understand the thermal stability of the road. Popular methods treat the upper boundary as a temperature-controlled model (TCM), where temperature of the upper surface is set as a sinusoidal function. This simple function, however, fails to identify the influences of solar irradiance, heat convection, and thermal irradiance on the heat transfer on the ground surface. Here we introduce a heat-flux model (HFM) to calculate the heat fluxes at the embankment upper surface and at the adjacent ground surface. HFM-predicted temperature under an embankment is compared against the observed temperature to validate the model, and is compared to the TCM-predicted temperature. While TCM-predicted temperatures and HFM-predicted ones are similar in trend and in pattern, the HFM-predicted temperatures are far more coincident with the observed ones. The pros and cons of both HFM and TCM are discussed. Further studies are expected to use HFM to understand the heat flux components such as solar absorption, heat convection, and thermal irradiance on the temperature of permafrost under embankments.
在多年冻土地区修建道路面临挑战，因为多年冻土对温度升高很敏感。由于路堤主要在上表面获取/散失热量，准确模拟上表面的热传递对于理解道路的热稳定性至关重要。常用方法将上边界视为温度控制模型（TCM），其中上表面温度被设定为正弦函数。然而，这个简单的函数无法识别太阳辐射、热对流和热辐射对地面热传递的影响。在此，我们引入一个热通量模型（HFM）来计算路堤上表面和相邻地面的热通量。将HFM预测的路堤下温度与观测温度进行比较以验证模型，并与TCM预测的温度进行比较。虽然TCM预测的温度和HFM预测的温度在趋势和模式上相似，但HFM预测的温度与观测温度更为吻合。讨论了HFM和TCM的优缺点。预计未来的研究将使用HFM来理解诸如太阳吸收、热对流和热辐射等热通量分量对路堤下多年冻土温度的影响。
