季节性寒区隧道保温隔热层厚度计算方法

为了解决冻结锋面移动可能带来的保温层厚度不足的问题。以河北延崇高速棋盘梁隧道为研究对象，采用现场监测、数值模拟以及理论推导等研究方法对季节性寒区隧道冻结锋面的移动规律进行探究，并结合移动规律研究结果得出考虑冻结锋面移动规律的保温隔热层计算公式。结果表明：（1）在同一断面内，由于较厚的仰拱填充对温度的传递起到了一定的阻碍作用，冻结锋面在拱顶处的深度大于边墙处的深度。（2）季节性寒区隧道的冻结锋面随着时间的推移，冻融循环的反复进行，其深度会逐渐加深，最终趋近于某一稳定值。（3）不同断面的冻结锋面最终稳定深度与断面处年平均温度呈现线性相关关系，而与温度振幅呈现非线性相关的关系。（4）对所推导的保温隔热层厚度计算公式中的冻深参数进行了基于冻结锋面移动规律的修正，保证了保温层长期的有效服役。

Calculation method of tunnel insulation layer thickness in seasonal cold zone

In order to solve the problem of insufficient insulation thickness caused by the movement of the freezing front. Taking the Jinjiazhuang Tunnel of Yan-Chong Expressway in Hebei Province as the research object, the method of field monitoring, numerical simulation and theoretical derivation is used to explore the movement law of the freezing front of the tunnel in the seasonal cold area, and combined with the research results of the movement law, it is concluded that the freezing front is considered Calculating formula for heat preservation and heat insulation layer with regular movement The results show that: (1) In the same section, because the thicker inverted arch filling has a certain hindrance to the temperature transfer, the depth of the freezing front at the vault is greater than that at the side wall. (2) As time goes by, the freezing front of tunnels in seasonal cold regions will undergo repeated freezing and thawing cycles, and its depth will gradually deepen and eventually approach a certain stable value. (3) The final stable depth of the frozen front at different sections has a linear correlation with the annual average temperature at the section, and a nonlinear correlation with the temperature amplitude. (4) The freezing depth parameter in the calculated formula for calculating the thickness of the thermal insulation layer is modified based on the movement law of the freezing front, which ensures the long-term effective service of the thermal insulation layer.