高纬度深季节冻土区路基冻胀的实体工程监测研究

Field Test Study on the Frost Heave of an Embankment in High-latitude and Deep Seasonally Frozen Area

为分析高纬度深季节冻土区路基冻胀特性,揭示其影响因素和时空规律,基于内蒙古S201线室韦～拉布大林公路深季节冻土区路基冻胀现场试验断面监测数据,分析了连续2年路基的地温特征、变形过程和水分场。监测数据表明:该地区路基冻胀显著,外界环境的冻融循环是引发路基冻胀发生和发育的主要驱动因素,而路基体的水分迁移和聚集是造成冻胀发生的主要因素。路基土体和4.0m以上的浅层地基是承受冻融循环影响的主要区域,此部分也是水分聚集的主要区域,体积含水率在70%以上。路基在每年的1月底达到最大冻胀,最大冻胀量可达3.4cm。路基分层变形数据显示,路基顶部1.0m以下范围是冻胀发生的主要区域,此部分冻胀量占路基总体冻胀的90%以上,需要重点关注。

In order to analyze the frost heat characteristics of the embankments in high-latitude and deep seasonally frozen areas and to reveal its influential factors and temporal and spatial developments,based on the monitoring data collected from the frost heave test section along the Shiwei-Labudalin Road of S201 in Inner Mongolia,the geo-temperature regime,deformation process and moisture field for 2 successive years are analyzed.The monitoring data show that,the frost heave at the test site is remarkable and that the exterior thawing-freezing cycling is a main driving factor while the moisture migration and accumulation inside embankment is a main factor for the development of frost heave.The embankment body as well as the shallow ground with a depth in 4 mare main regions influenced by thawing-freezing cycling,where is also a main region of moisture accumulation with a moisture content over 70%.The embankment reaches to maximum value of frost heave of 3.4 cm at the end of January.The layered deformation data show that the embankment body in 1 mfrom the top is the main area that frost heave happens,the frost heave at which accounts for over 90%of the total frost heave of the embankment,thus this area is a key concern.