关键词: 寒区隧道, 抗防冻设计, 设计分区, 主导因素

Abstract: Antifreezing of groundwater (freezethaw) and the resistance of structural freezing of tunnels are crucial to tunnel technology in cold regions; the core is the groundwater antifreeze (freezethaw), whereas the key is the resistance of structural freezing. In this study, the geographical location and antifreezing technologies of existing traffic tunnels and the occurrence of frost damage in cold regions are introduced; moreover, the design divisions of a tunnel in highlatitude and highaltitude cold regions are proposed. Then, the status and problems of related technical standards for highway and railway tunnels in cold regions are introduced. Further, the optimization direction of antifreezing measures for tunnels is proposed. Finally, the dominant factors of the antifreezing design of the tunnels in cold regions are analyzed using the longitudinal temperature field in the operating railway tunnel. The results indicate the following. (1) The highlatitude or highaltitude cold regions can be classified into five design divisions according to the average temperature in the coldest month and average annual temperature. (2) The establishment of insulation and drainage system is a key factor in the antifreezing of tunnels in the cold regions， measures, such as improving the frost resistance capacity of the structure and insulation layers, can be adopted to prevent the structure from frost. (3) The natural difference in air pressure formed by the height difference in the tunnel entrance is the dominant factor affecting the longitudinal distribution of the temperature field in long tunnels and antifreezing design in cold regions.

Key words: tunnels in cold regions, antifreezing design, design division, dominant factors