我国季节冻土区路堑段路基水热特性及冻胀发展过程监测研究

路基冻胀问题严重影响季节冻土区高速铁路的运营安全。基于哈大客运专线长春市郊区试验路段某一路堑段路基，采用级配碎石+防水土工膜+A、B组填料+防水土工膜的新型路基结构，对不同位置及深度的温度、水分及冻胀变形进行监测，分析了季节冻土区不同深度下的水热特性及冻胀随温度变化的特征。结果表明：复合土工膜对路基冻结期水分迁移起到隔断作用，对于路堑式路基而言，由于边坡汇水作用，坡脚冻深大于路基中心。路基基床上层及中层变形主要受含水量影响较大，而下层由于温度基本为正温变形主要受路基填料质量控制。

Study of water-thermal characteristics and frost heave process monitoring in the roadbed of cutting section in seasonally frozen soil regions

The safe operation of high-speed railway was seriously affected by the frost heave in seasonally frozen regions.Based on a cutting section of roadbed in Changchun City along Harbin-Dalian Passenger Railway Line,a new subgrade structure with graded broken stone,waterproof geomembrane,packing and composite geomembrane was constructed.Temperature,water content and frost heave in different positions and depths were monitored and then the hydro-thermal and frost heave properties in the subgrade of seasonally frozen regions were studied.The results showed that the composite geomembrane could prevent water migration in frozen period.For the roadbed in cutting section,the frozen depth in slope toe is relative deep,deeper than that at the central of the subgrade.The primary factor was water content,which effected the frost heave in upper and middle layers,and the deformation in lower layer was controlled by the quality of filler due to the temperature was always higher than zero.