Durable and Cost-Effective Proactive Cooling Measures for Permafrost Embankments: Research Progress and Engineering Applications of Ventilated Duct Systems

In linear engineering construction conducted in permafrost regions, the stability of the embankment is frequently compromised by permafrost degradation. To address it, ventilated ducts can be employed to cool the embankment and the underlying soil. The paper provides a comprehensive review and analysis of recent advancements in the design and application of duct-ventilated embankments, drawing from both domestic and international research. The efficacy of these embankments in cooling is influenced by various factors, including the size of the ventilated ducts, the layout position, and the structure of the embankment. Laboratory tests must be carefully controlled for airflow velocity and temperature to ensure accurate results. Additionally, the paper introduces the use of a random forest algorithm for predicting soil temperature based on field monitoring data. In assessing the cooling capacity of ventilated ducts, both numerical and empirical models are prevalently employed. However, the influence of airflow velocity on cooling capacity remains inadequately quantified. Consequently, there exists a pressing demand in engineering for more succinct, universally applicable, and precision-oriented numerical calculation models. The paper also presents a detailed examination of numerous case studies, highlighting the structural characteristics, merits, drawbacks, and current status of applications for the new ventilated ducts. The information is intended to serve as a valuable reference for embankment construction in high-altitude permafrost regions.