Abstract: Inorder tohelp solve ice problem on the lining surface to ensure operation safety in cold region tunnels, the causes and early warning technology of icingwere studied. Firstly,main types of icing problems in tunnelswere summarized,reasons for failure of waterproof and insultation measures were analyzed. And then, a maintenance joint structure and freezing forecast and prewarning method were proposed to deal with the icing problem. Finally, the tunnel icing prediction and early warning system based on Internet of Things technology was used to guide deicing work. The results show that waterproofing layer is injured by surrounding rock pressure and shear force during service, tunnel drainage system is silted and blocked during operation, and compressed insulation layer between the initial support and the second lining gradually failed under the freeze-thaw cycles, all of these leading to the failure of waterproof and insultation measures, and that the maintenance joint structure introduces the drainage hole, the seal ring and the maintenance hole, which realizes the renewal of the seal ring.

Key words: tunnel in cold region, ice covering, forecasting and earlywarning, frost damage, internet of things