Frost Mitigation Techniques for Tunnels in Cold Regions: The State of the Art and Perspectives

Tunnels located in cold regions are vulnerable to frost damage resulting from the special atmosphere, which directly threatens safety of tunnel structure and operation. Frost problems tunnels have not been fundamentally resolved. This paper reviews design theory mitigation techniques currently used design, construction maintenance region tunnels. The depths freezing thawing heaving force key indexes theory. Insulation is main technology prevent thawing, active heating has also applied practice. In construction, reducing heat hydration blasting by specific winter can freeze–thaw damages. operation, restoration drainage systems, reinforcement structures reinstallation freezing-prevention systems effective measures treat problems. Finally, some constructive suggestions opinions put forward improve service performance