论文部分内容阅读
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 degradation law of the upper limit of artificial permafrost of XPS thermal insulation board in expressway in eastern permafrost region of Qinghai-Tibet Plateau, to ensure the long-term thermal stability of subgrade in permafrost region and to reduce the roadbed disease caused by the degradation of upper limit of permafrost, The vertical and horizontal distribution of ground temperature of XPS thermal insulation board in high temperature permafrost zone and the degradation characteristics of upper bound of permafrost in the early stage of embankment construction are analyzed by using the measured data of on-site ground temperature. Then, the unsaturated soil seepage and heat conduction theory are used to solve the hydrothermal Coupling differential equations to achieve the full coupling of the frozen soil moisture field and the temperature field, and then compare the temperature field simulated by the hydrothermal coupling model with the field measured temperature field to verify the correctness of the model; and analyze the XPS insulation board subgrade in 5 At last, using MATLAB to analyze the main factors that affect the upper limit degradation of anthropogenic frozen soils, and then to analyze the degradation of the upper limit of artificial permafrost under different working conditions (including the type of filler, average annual ground temperature, subgrade height, XPS insulation board laying position and climate warming) It conducts multiple linear regression and establishes the calculation model of artificial permafrost upper bound of XPS insulation board in permafrost zone. The results show that the temperature on the left side of XPS insulation board is higher than the temperature on the right side of the embankment; the upper limit of artificial permafrost in the initial period of subgrade construction is lifted by 60cm first, then decreased by 10cm / year, and the change of upper limit of permafrost The upper bound of artificial permafrost and the time are all linearly increasing under the five conditions; the two main influencing factors that affect the upper limit degradation of artificial permafrost are filler type and climate warming; the model can be Provide technical reference for the future long-term deformation prediction and disease prevention and control of XPS thermal insulation board subgrade in permafrost freeway.