青藏铁路道砟层对冻土路基热状况影响分析  

Influence of the Ballast Layer of Qinghai-Tibet Railway on the Thermal Regime of the Frozen Soil Roadbed

作　　者：郑波[1,2,3] 张建明[1] 马小杰[4] 覃英宏[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室,甘肃兰州730000 [2]中国铁道科学研究院,北京100081 [3]中铁西南科学研究院有限公司,四川成都610031 [4]浙江建设职业技术学院,浙江杭州311231

出　　处：《中国铁道科学》2009年第1期8-12,共5页China Railway Science

基　　金：中国科学院寒区旱区环境与工程研究所知识创新工程项目(2004104);中国科学院知识创新工程重要方向性项目(KZCX3-SW-351);中国科学院知识创新工程重大项目(KZCX1-SW-04)

摘　　要：在青藏铁路北麓河试验段设置试验断面,对地温及热流量进行观测,研究青藏铁路道砟层对路基下伏冻土热状况的影响。研究分析表明:道砟层在暖季阻止外部热量进入下伏冻土,冷季阻止路基内部热量扩散,且道砟层在暖季保温效果明显,而在冷季其降温效果并不明显;相同深度处道砟层下土体的年平均温度比砂砾路面下土体的年平均温度约低2℃;道砟层对路基下伏冻土起降温效果主要是因为其在暖季屏蔽了大部分外界热量,促使道砟层下土体年总热量收支呈现负值,从而起到很好的降温效果。因此,铺设道砟层有利于冻土路基的热稳定性。In order to study the influence of railway ballast layer on the thermal regime of frozen soil road- bed, a test section was built at Beiluhe test site along Qinghai-Tibet Railway. Analyses of the monitoring results of ground temperature and heat flux show that the ballast layer can play an insulating role in protecting the permafrost of Qinghai-Tibet Railway, which can prevent outside heat accessing the frozen soil roadbed in warm season and keep heat from diffusing into outside in cold season. The insulating effect of the ballast layer is well in warm season, but the cooling effect of it is not obvious in cold season. Compared with the gravel surface, the cooling effect of the ballast layer is very evident. The annual mean ground temperature is about 2℃ lower than that at the same depth beneath the gravel surface. The main reason for the cooling effect of the ballast layer is that most of the heat is shielded in warm season, and the soil under the ballast layer has a negative heat budget, which plays a very well cooling effect to the frozen soil roadbed. The ballast layer is very helpful to protect the permafrost under the roadbed as well as can ensure the stability of frozen soil roadbed to some extent.

关 键 词：青藏铁路 多年冻土 道砟层 降温效果 路基稳定性 

分 类 号：U213.14[交通运输工程—道路与铁道工程]