• 标题：Cooling performance and deformation behavior of crushed-rock embankments on the Qinghai-Tibet Railway in permafrost regions
• 关键词：Crushed-rock embankment,Cooling performance,Deformation behavior,Qinghai-Tibet Railway,Permafrost region
• 作者：Bowen Tai, Qingbai Wu, Zhongqiong Zhang, Xiaoming Xu

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The structural functionality of roads and railways in warm permafrost regions is inflfluenced by both physical and mechanical processes at work within the underlying subgrade. This paper uses ten-years worth of monitoring data to examine the thermal regimes and deformation behaviors of three difffferent types of crushed-rock embankments employed in the construction of the Qinghai-Tibet Railway, which is located in a warm permafrost region of the Tibetan Plateau, China. More specififically, the effiffifficiency of U-shaped crushed-rock, crushed-rock revetment, and crushed-rock basement embankments in stabilizing permafrost temperature is evaluated with consideration to the permafrost table, ground temperature, and mean annual ground temperature. Then, deformation laws in the three embankments were analyzed. Finally, deformation characteristics and sources for general subgrade are discussed and summarized on the basis of monitoring data and previous research. Results show the permafrost table of each of the three crushed-rock embankments to be higher than that of the natural ground at all times, and that the underlying permafrost warms with time regardless of the type of embankment employed. The deformation characteristics of general subgrade in permafrost regions are determined to be nonuniform and persistent. Furthermore, U-shaped crushed-rock embankment out-performed both crushed-rock revetment embankment and crushed-rock basement embankment in terms of cooling capacity and ability to weaken the sunny-shady slope effffect. These fifindings stand to provide important guidance for understanding the deformation mechanisms of subgrade in warm permafrost regions, as well as for improving Qinghai-Tibet Railway embankment quality and operational safety