青藏铁路高温多年冻土区典型路基的长期热稳定性研究  

Long-term thermal stability study of the typical embankment along the Qinghai-Tibet Railway in warm permafrost regions

作　　者：徐岳震 申明德 周志伟 马巍 李国玉 XU Yuezhen;SHEN Mingde;ZHOU Zhiwei;MA Wei;LI Guoyu(State Key Laboratory of Frozen Soil Engineering,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院西北生态环境资源研究院冻土工程国家重点实验室,甘肃兰州730000 [2]中国科学院大学,北京100049

出　　处：《冰川冻土》2022年第6期1784-1795,共12页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金重点项目(41630636);第二次青藏高原综合科学考察研究项目(2019QZKK0905)资助。

摘　　要：利用2006—2020年青藏铁路沿线多年冻土区长期地温监测资料,选取高温多年冻土区内三类典型路基结构(普通路基、U型块石路基、块石护坡路基)对应的长期监测断面,对15年间路基下20 m深度范围内温度场、年平均地层温度及年最高地层温度的演化规律进行分析和研究。监测和分析结果表明:普通路基左右路肩下冻土层的年平均地层温度增长速率高于天然场地同深度冻土层的增长速率。U型块石路基下年平均地温始终低于天然场地年平均地温并保持一定差值,且左右路肩下的地温差异不可忽视。块石护坡路基左路肩的年平均地温与天然孔相差不大,而右路肩的年平均地温始终低于天然孔,左右路肩下的地温差异要小于U型块石路基。普通路基下人为多年冻土上限始终低于天然多年冻土上限。U型块石路基和块石护坡路基左右路肩的人为多年冻土上限均已抬升至路基本体内,左右路肩的融深差值为1.0~1.5 m,块石护坡路基融深差值略低于U型块石路基。综合来看,由于工程及气候变暖等热扰动的影响,高温多年冻土区内的普通路基已不能维持其下多年冻土的热稳定性,需采取一定的主动降温补强措施。U型块石路基及块石护坡路基对其下多年冻土具有一定的主动降温效果,但左右路肩的地温差异问题仍需引起重视。Using the long-term ground temperature monitoring data of the permafrost zone along the Qinghai-Tibet Railway from 2006 to 2020, three types of typical roadbed structures were analyzed. Traditional embankment(TE), U-shaped crushed rock embankment(UCRE) and crushed rock revetment embankment(CRRE) were included the three types of typical roadbed, which were selected to the long-term monitoring sections within the warm permafrost zones. The evolution of ground temperature field, mean annual ground temperature(MAGT) and annual maximum ground temperature(AMGT) in the depth range of 20 m under the embankment were analyzed and studied since 15 years of operation. The monitoring and analysis results show that: the growth rate of MAGT under the left and right shoulders of the TE is always higher than that of the same depth in the natural site. The MAGT under the UCRE is always lower than the natural site and always maintains a certain difference, whereas, the difference in ground temperature under the left and right shoulders is also not negligible. The MAGT of the left shoulder in the CRRE is not much different from that of the natural hole, while the MAGT of the right shoulder is always lower than that of the natural hole, and the differ in ground temperature between the left and right shoulders is smaller than that of the UCRE. The artificial permafrost table(APT) under the TE is always lower than that of in the natural site. Both the UCRE and CRRE, the APT in the left and right shoulders of them has been elevated into the embankment, and the differ of APT between the left and right shoulders is about 1.0~1.5 m. the differ of APT between the left and right shoulders in the CRRE is slightly lower than that of UCRE. Overall, because of the influence of thermal disturbance about engineering and climate warming, the TE in the warm permafrost zones cannot keep the thermal stability of permafrost under the embankment. Some active-cooling and reinforcement measures need to be taken. Both of the UCRE and CRRE, have a certain a

关 键 词：青藏铁路 高温多年冻土区 块石路基 冻土上限 温度场 长期运维 

分 类 号：U213.1[交通运输工程—道路与铁道工程]