摘要
针对兰新铁路武威段的路基冻胀选取典型地段进行冻胀过程的现场实测,包括不同深度处的温度、湿度及冻胀量从秋季到冬季再到春季的变化时程。通过对实测数据的分析,力求弄清该干旱低水位地区铁路路基发生冻胀的水分来源。实测数据及分析表明,由于入冬前路基浅层局部土体有一定体积含水率,浅层冻结之后,减小水分的蒸发;同时在温度梯度作用下,有不可忽略的地下水气向上迁移,加大浅层的冻胀。结合此前业内提出的“锅盖效应”概念,提出“时变覆盖效应”概念,可以解释此种环境下路基内的水分迁移及冻胀。
Field measurements of frost heave process in Wuwei section of Lan-Xin Railway were carried out,including the variation of temperature,humidity and frost heave amount at different depths from autumn to winter and then to spring.Through the analysis of the measured data,the attempt was made to find out the water source of frost heave of Railway Subgrade in this arid and low water level area.The measured data and analysis show that the evaporation of water decreases due to the water content in the shallow part of the subgrade freeze before winter,and the upward migration of groundwater vapor cannot be neglected under the action of temperature gradient,which increases the frost heave in the shallow layer.In combination with the concept of“canopy effect”put forward by previous studies,the concept of“time-varying canopy effect”was put forward,which can explain the moisture migration and frost heaving in the subgrade under this environment.
作者
仝睿
宋二祥
赵志宏
于洪钦
张爱涛
TONG Rui;SONG Erxiang;ZHAO Zhihong;YU Hongqin;ZHANG Aitao(Key Laboratory of Civil Engineering Safety and Durability of the State Ministry of Education,Tsinghua University,Beijing 100084,China;Wuwei Works Section of China Railway Lanzhou Bureau Group Co.,Ltd,Wuwei 733000,China)
出处
《铁道科学与工程学报》
CAS
CSCD
北大核心
2020年第8期1949-1956,共8页
Journal of Railway Science and Engineering
基金
国家自然科学基金资助项目(51778339,41272279)
国家重点基础研究发展计划(973计划)项目(2014CB047003)。
关键词
铁路路基
冻胀
现场实测
时变覆盖效应
体积含水率
railway subgrade
frost heave
field measurement
time-varying canopy effect
water content
