摘要
季节冻土区路基的冻胀变形影响高速列车的运行速度、行车安全。以普通级配碎石路基结构为原型,建立轨下基础热-力耦合模型和路基结构外力作用模型,通过温度场和变形场的现场监测数据、力学特性计算的文献资料验证了模型的可靠性。在此基础上建立水泥稳定碎石路基、保温强化层+级配碎石路基、保温强化层+水泥稳定碎石路基3种防冻胀路基模型,计算冻胀变形和受力特性。结果表明:保温强化层和水泥稳定碎石填料均有效减小了路基的冻胀变形,其中保温强化层+水泥稳定碎石路基的冻结深度和最大冻胀量最小,分别为0.8 m、1.585 mm;保温强化层可减小基床表层竖向应力,且弹性模量较大的水泥稳定碎石可加速竖向应力的衰减,使得基床底层承受应力减小。保温强化层+水泥稳定碎石基床表层结构可为季节冻土区高速铁路路基结构的选型提供参考。
Frost heaving deformation of the subgrade in the seasonally frozen region affects the running speed and safety of high-speed trains.Taking ordinary-graded macadam subgrade structure as the prototype,we established the thermal-mechanical coupling model of subgrade foundation and the external force model of subgrade whole structure.Then the temperature field,deformation field and structural mechanical parameters were calculated and compared with literature data,which further verified the reliability of the model.On this basis,three anti-frost heave structural models were established,including the cement stabilized gravel subgrade,thermal insulation strengthening layer with graded macadam subgrade,and thermal insulation strengthening layer with cement stabilized macadam subgrade.Finally,the frost heave deformation and stress characteristics were calculated.The results show that the thermal insulation strengthening layer and cement stabilized macadam filler can effectively reduce the frost heaving deformation of the subgrade.The frost depth and maximum frost heaving of the thermal insulation strengthening layer with cement stabilized macadam structure are the smallest,which are 0.8 m and 1.585 mm.Moreover,the thermal insulation strengthening layer can reduce the vertical stress of the surface layer of the subgrade,and the cement stabilized macadam with larger elastic modulus can accelerate the attenuation of vertical stress and reduce the stress of bottom layer of subgrade.The thermal insulation strengthening layer with cement stabilized macadam subgrade surface structure can provide references for the selection of high-speed railway subgrade structure in the seasonal frozen zone.
作者
宋宏芳
岳祖润
李佰林
张松
SONG Hong-fang;YUE Zu-run;LI Bai-lin;ZHANG Song(School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang,Hebei 050043,China;School of Graduate,Shijiazhuang Tiedao University,Shijiazhuang,Hebei 050043,China;Key Laboratory of Roads and Railway Engineering Safe Control of Ministry of Education,Shijiazhuang Tiedao University,Shijiazhuang,Hebei 050043,China;Beijing China Coal Mine Engineering Co.,Ltd.,Beijing 100013,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2019年第10期4041-4048,共8页
Rock and Soil Mechanics
基金
中国铁路总公司科技研究开发计划项目(No.2017G002-W,No.2017G008-A)
河北省在读研究生创新能力培养资助项目(No.CXZZBS2018149)
道路与铁道工程安全保障省部共建教育部重点实验室(石家庄铁道大学)开放课题(No.STKF201719)~~
关键词
路基
季节冻土区
高速铁路
防冻胀结构
冻胀变形
层间力学特性
subgrade
seasonal frozen soil regions
high-speed railway
anti-frost heaving structure
frost heaving
mechanical property between layer
