摘要
块碎石路基是青藏铁路中常见的主动冷却路基形式。为了验证该工程措施的有效性,有必要对其长期降温效果进行研究。基于青藏铁路北麓河非正线试验段10 a地温监测数据,对比分析了封闭块石护坡、块石护坡加厚、碎石护坡路基对下部多年冻土的降温效果。研究结果表明,在工程活动和气温变化影响下,三种护坡路基的降温过程存在快速降温、稳定降温、降温减弱三个阶段,其中以碎石护坡路基的降温效果表现最佳。从观测期内的路基下部地温变化和热状态来看,三种路基中心下部原多年冻土上限附近降温速率分别为0.39、0.45、0.47℃/10 a。相较于封闭块石护坡路基,块石护坡加厚、碎石护坡路基下部土体地温分布具有较好的对称性。然而,块碎石护坡路基仅在路基下部5.0 m深度范围内存在降温效果,难以保证深层多年冻土的稳定。
Crushed rock and gravel embankmentsare common types of active cooling roadbed in Qinghai-Tibet railway.To verify the effectiveness of the engineering measures,it is necessary to research their long-term cooling effects.Based on the 10-year monitoring data of ground temperature in the Beiluhe experimental sections along the Qinghai-Tibet Railway,a comparison and analysis were made on the cooling effects of different crushed rock structures,including closed-system crushed rock revetment,open-system crushed rock revetment and open-system crushed gravel revetment,on the permafrost below the embankment.The results show that the embankment with the above three types of crushed rock revetments indicates a three-staged cooling process under the effect of engineering actives and warning climate,including rapid cooling,stable cooling and reduced cooling,with the open-system crushed gravel revetment performing the best.In this process,the cooling rates near the original permafrost table are respectively 0.39,0.45,and 0.47℃/10 a,in terms of the permafrost temperature variation and thermal regime.Compared with the closed-system crushed rock revetment,the soil temperature distributions beneath the open-system crushed rock revetment and open-system gravel rubble revetment perform a better symmetry.However,the aforementioned embankments have a cooling effect on underlying soil in the depth range of about 5.0 m,which is difficult to ensure the stability of deep permafrost.
作者
赵翃婷
吴青柏
侯彦东
蒋观利
高思如
王陆阳
ZHAO Hongting;WU Qingbai;HOU Yandong;JIANG Guanli;GAO Siru;WANG Luyang(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;Key Laboratory of Disaster Prevention and Mitigation in Civil Engineering of Gansu Province,Lanzhou University of Technology,Lanzhou 730050,China)
出处
《铁道学报》
EI
CAS
CSCD
北大核心
2022年第5期132-140,共9页
Journal of the China Railway Society
基金
国家自然科学基金(41690144,41861010)。
关键词
青藏铁路
块碎石护坡
降温效果
地温变化
多年冻土上限变化
Qinghai-Tibet railway
crushed rock and gravel revetment
cooling effect
ground temperature
variations of permafrost table