摘要
为揭示青藏高原东部高温冻土区高速公路XPS保温板路基的人为冻土上限退化规律,确保高温冻土区路基的长期热稳定性,减小因人为冻土上限退化引起的路基病害,首先,利用现场地温实测资料分析高温冻土区XPS保温板路基地温的纵、横向分布特征,以及路基修筑初期人为冻土上限的退化特征;然后,采用非饱和土渗流与热传导理论求解冻土水热耦合微分方程,实现冻土水分场与温度场的全耦合,进而将水热耦合模型模拟所得温度场与现场实测温度场进行比较,以验证该模型的正确性;并分析XPS保温板路基在5种工况(包括填料类型、年平均地温、路基高度、XPS保温板铺设位置和气候变暖)下人为冻土上限的退化规律;最后,采用MATLAB分析影响人为冻土上限退化主要因素,进而对其进行多元线性回归,建立高温冻土区XPS保温板路基人为冻土上限计算模型。研究结果表明:XPS保温板路基左侧一定范围内温度比右侧对应范围的温度高;路基修筑初期人为冻土上限先抬升60cm,然后以10cm/年下降,冻土上限的变化导致深部冻土层存在一定幅度的升温;5种工况条件下,路基人为冻土上限与时间均呈线性增加关系;影响人为冻土上限退化的2个主要影响因素为填料类型和气候变暖;该模型可为今后开展高温冻土区高速公路XPS保温板路基长期变形预测与病害防治提供技术参考。
In order to reveal the decline laws of permafrost table of expressway subgrades in warm frozen soil regions of Qinghai-Tibet Plateau,ensure the long-term thermal stability of subgrades in warm permafrost regions and reduce subgrade diseases which caused by the degradation of artificial permafrost table,firstly,the longitudinal and lateral distributions of ground temperature of XPS insulated board subgrade and degradation characteristics of artificial permafrost table at early stage of subgrade construction were analyzed.Secondly,the moisture-heat coupling differential equation of permafrost was solved through unsaturated soil seepage and heat transfer theory,to realize the unity coupling of moisture field and temperature field of frozen soils.The temperature field simulated by moisture-heat model was compared with the measured temperature field to verify the correctness of the model.Then,the degradation laws of artificial permafrost table of XPS insulated board subgrade under five conditions（filling type,annual mean ground temperature,height of subgrade,laying location of XPS thermal insulation board and climate warming）were analyzed.Finally,main factors influencing the degradation of artificial permafrost table were calculated by MATLAB,and the multivariate linear regression was carried out,so as to establish the calculation model for artificial permafrost table of XPS insulated board subgrade in warm permafrost regions.The results show that temperatures on the left side of XPS insulated board subgrade is higher than that on the right side within a certain range.The artificial permafrost table lifts 60 cm at the early stage of subgrade construction,then,decreases gradually with a speed of10 cm per year.The change of permafrost table leads to a certain increase of temperature in deep permafrost.Under the five conditions,the artificial permafrost table of XPS insulated board subgrade in warm permafrost regions increases linearly with time.Filling type and climate warming are two major factors affecting the decline of permafrost table.The model can provide favorable references for prediction and prevention of long-term deformation of highway subgrades in warm permafrost regions.
作者
邰博文
刘建坤
房建宏
徐安花
刘磊
王腾飞
TAI Bo-wen LIU Jian-kun FANG Jian-hong XU An-hua LIU Lei WANG Teng-fei(School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, China Key Laboratory of Highway Construction g~ Maintenance Technology in Permafrost Region, Qinghai Research Institute of Transportation, Xining 810008, Qinghai, China)
出处
《长安大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2017年第4期1-11,共11页
Journal of Chang’an University(Natural Science Edition)
基金
supported by the National Natural Science Foundation of China (No.41271072and 51378057)
Science and Technology Project of Qinghai Province(No.2013-J-770)
Science and Technology Project of Shenshuo Railway Branch(No.2015-10)
关键词
道路工程
冻土上限计算模型
数值计算
共和—玉树高速公路
road engineering
calculation model of permafrost table
numerical calculation
Gonghe-Yushu Expressway
