Analytical model of vapor flow driven by pot cover effect in frozen soils

The pot cover effect leads to the accumulation of soil vapor beneath the structural cover layers of roads or airport runways, where it undergoes a phase change to ice. This process can induce freeze-thaw degradation of the pavement or concrete, resulting in reduced strength and potential structural failure. The pot cover effect has been well studied in field and indoor experiments, but its soil vapor migration flow calculation model is still a challenge that urgently needs to be solved. To overcome this problem, a new concept of the soil vapor thermal diffusion coefficient is proposed, based on which a simplified soil vapor flow model is derived. Furthermore, the reliability of the model is validated by comparing its calculations with several indoor experimental datasets. The results show that the proposed model can be calculated using measurable macroscopic parameters and provides higher accuracy than traditional models. The findings provide a theoretical basis for studying and mitigating the pot cover effect in roadbeds and airport infrastructure in cold regions.