In the vast, icy expanses of the Qinghai-Tibet Plateau, a critical lifeline stretches across the frozen landscape: the Qinghai-Tibet Highway (QTH). This engineering marvel, a vital artery for trade and transport, faces unique challenges due to the permafrost regions it traverses. Recent research, led by Qin-Guo Ma from the State Key Laboratory of Subtropical Building and Urban Science at South China University of Technology, sheds light on the diseases plaguing the embankments of this highway, particularly those equipped with Two-Phase Closed Thermosyphons (TPCTs).
TPCTs, a type of heat pipe, are widely used to cool the embankments and prevent them from melting the permafrost beneath. However, despite their efficiency, the complex environment, climate warming, and the heat absorption of asphalt pavements lead to various issues. Ma and his team studied 31 sections of embankments with TPCTs along the QTH, using a technique called Small Baseline Subset-Interferometric Synthetic Aperture Radar (SBAS-InSAR) to monitor deformation.
The results, published in the journal “Advances in Climate Change Research” (translated from Chinese), reveal that the average annual deformation rate of these embankments is -4.077 ± 1.979 mm per year. This deformation is influenced by various factors, including orientation, elevation, soil type, ice content, mean annual ground temperature, and the form in which TPCTs are installed.
The main diseases identified are longitudinal cracking, transverse cracking, and differential settlement. Longitudinal cracking, caused by uneven temperature distribution, tends to occur in multiple lines on embankments with inclined TPCTs, while it appears as a single line on embankments with vertical TPCTs. “Longitudinal cracking mainly caused by uneven temperature distribution tends to occur in multiple lines on embankment with inclined TPCTs, while it appears as a single line on embankment with vertical TPCTs,” Ma explained.
Transverse cracking, related to uneven temperature distribution, fatigue damage from repeated freezing-thawing action, traffic load, and water infiltration, typically occurs in the high-temperature area between two adjacent TPCTs. Differential settlement, influenced by the TPCTs installing form and the shady-sunny slope effect, varies in severity and location depending on the TPCTs’ orientation.
For the maritime sector, understanding these issues is crucial, especially for companies involved in Arctic and Antarctic logistics, as similar challenges may arise in other permafrost regions. The research highlights the importance of careful planning and monitoring in such environments, which can help prevent costly repairs and delays.
Moreover, the findings present opportunities for innovation in cooling technologies and monitoring techniques. Companies specializing in remote sensing, geotechnical engineering, and climate adaptation could find valuable insights and potential applications in this research.
As Ma’s study underscores, ensuring the long-term service safety of infrastructure in permafrost regions is a complex task. However, with continued research and technological advancements, the maritime sector can better navigate these icy challenges and seize the opportunities they present.