水-热耦合作用下严寒地区高速铁路隧道温度场分布规律

为研究严寒地区高速铁路隧道修筑后,衬砌背后围岩冻结引发的隧道冻胀病害问题,以吉图珲客运专线榆树川隧道为例,综合考虑水分迁移和冰-水相变潜热对衬砌-围岩热传导的影响,建立了围岩冻结过程中的水-热耦合模型,结合现场实测大气温度,利用有限元法对榆树川隧道温度场进行了计算,得到了严寒地区隧道温度场的分布规律,确定了隧道发生冻结的最不利位置和最不利时间,并建立了隧道最大冻结深度与大气年平均温度之间的关系,分析了保温层对隧道防冻的作用,给出了保温层厚度和导热系数与隧道冻结深度的关系,提出了防止榆树川隧道发生冻结的保温层导热系数和厚度的建议值.

Numerical Analysis on the Distribution Law of Temperature Field of a High-speed Railway Tunnel in Cold Regions

For the high-speed railway tunnel in cold regions, the frost heave of the surrounding rock behind the lining causes the tunnel disease. Taking the Yushuchuan tunnel on the Jituhui passenger dedicated line as an example, a numerical heat-moisture coupled model considering heat conduction, water migration and phase transition for the tunnel in cold regions is established. Meantime, the temperature field of the Yushuchuan tunnel is calculated. Then, the unfavorable freezing position and the unfavorable freezing time are determined, and the relationship between the maximum freezing depth at the unfavorable freezing position and the mean annual temperature is established, which provides a basis for determining the freezing depth at different depths in the tunnel. Afterwards, the thermal insulation effect of thermal insulation layer on thermal state is analyzed. In addition, the optimum thickness and thermal conductivity of the thermal insulation layer are suggested to prevent the tunnel from freezing. This study will provide a theoretical reference for the insulation layer design of the tunnel in cold regions.