Understanding the long‐term role of cooling the underlying permafrost of the crushed rock structure embankment (CRSE) along the Qinghai–Xizang Railway (QXR) is crucial for the railway's safe operation. The thermal regime of the permafrost under the CRSE is analyzed here using monitoring data of soil temperature from 2005 to 2015. The results show that the CRSE plays an important long‐term role in cooling the underlying permafrost under the present climate change conditions; however, different types of CRSEs have different cooling effects. A U‐shaped crushed rock embankment and a crushed rock berm embankment with debris rock revetment can maintain the cooling of the permafrost underlying the embankment under a future climate warming of 1.0°C. Moreover, under an increase in air temperature of 0.5°C, a crushed‐based rock embankment and a crushed rock revetment embankment can maintain the cooling of the underlying permafrost when its mean annual ground temperature is below −1.0°C. The long‐term role of cooling the underlying permafrost of CRSEs indicates that the QXR must use reinforcing engineering techniques to ensure its safe operation and adaptation to a temperature increase of 1.5°C.

中文翻译：

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冷却青藏铁路沿线碎石结构路基的多年冻土的长期作用

了解冷却青藏铁路（QXR）沿线碎石结构路基（CRSE）的永久冻土的长期作用对于铁路的安全运营至关重要。本文利用2005年至2015年的土壤温度监测数据分析了CRSE下的多年冻土的热状况。结果表明，在当前气候变化条件下，CRSE在冷却潜在的多年冻土方面起着重要的长期作用；但是，不同类型的CRSE具有不同的冷却效果。AU型碎石路堤和碎石护堤碎石路堤路堤可在未来气候变暖1.0°C时保持路堤下方的多年冻土的冷却。此外，在气温升高0.5°C的情况下，当年平均地面温度低于−1.0°C时，碎石路堤和碎石护岸路堤可以保持地下多年冻土的冷却。冷却CRSE永久冻土的长期作用表明，QXR必须使用加固工程技术来确保其安全运行并适应1.5°C的温度升高。