The thawing and warming of ice-rich permafrost present a considerable threat to the long-term stability of the Qinghai–Xizang Railway (QXR) on the roof of the world—that is, the Qinghai–Xizang Plateau (QXP). In this review, we explore the extent of the observed permafrost degradation and embankment damage under the coupled impacts of climate change and engineering construction. The ice-rich permafrost beneath the embankment presents a substantial threat to the thermal–mechanical stability of the embankment due to the permafrost’s accelerated and amplified degradation. The observed embankment deformation has a potential high risk of thaw settlement, especially for 656 embankment-bridge sections, whose potential high risk of thaw settlement may be as great as 25%. Several techniques for roadbed cooling can be used to alleviate these impacts, including crushed rock structure embankments (CRSEs), thermosyphons, and reinforcement measures, which have been demonstrated to be successful in cooling the underlying permafrost and stabilizing an embankment. Under future climate change and permafrost degradation, however, the QXR still faces a high risk of embankment damage caused by permafrost degradation and requires more effective methods to reinforce the thermal–mechanical stability of permafrost. Therefore, a better understanding of such high-risk regions is needed, and roadbed cooling techniques will require further adaption in order to address the issues brought by climate change.

中文翻译：

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多年冻土退化威胁青藏铁路

富含冰的多年冻土的融化和变暖对世界屋脊——青藏高原上的青藏铁路（QXR）的长期稳定构成了相当大的威胁。在这篇综述中，我们探讨了在气候变化和工程建设的共同影响下观察到的永久冻土退化和路堤损坏的程度。由于永久冻土加速和加剧的退化，路堤下方富含冰的永久冻土对路堤的热机械稳定性构成了重大威胁。观测到的路堤变形存在潜在的高融沉风险，特别是656个路基桥段，潜在的融沉高风险可能高达25%。可以使用多种路基冷却技术来减轻这些影响，包括碎石结构路堤（CRSE）、热虹吸管和加固措施，这些技术已被证明可以成功地冷却下面的永久冻土并稳定路堤。然而，在未来气候变化和多年冻土退化的情况下，QXR仍然面临着因多年冻土退化引起的路堤损坏的较高风险，需要更有效的方法来增强多年冻土的热力稳定性。因此，需要更好地了解这些高风险地区，路基冷却技术也需要进一步调整，以解决气候变化带来的问题。