Method for preventing tunnel freezing damage of seasonally frozen regions

Abstract

The invention belongs to the field of tunnel projects, the field of frozen earth projects and the field of protecting projects and provides a method for effectively preventing freezing damage of seasonally frozen regions. The method has the advantages that the method does not continue traditional thermal insulation methods to prevent and process tunnel freezing damage, the method is based on reliable water stopping technological approaches, the water stopping performance of a dense quick lime layer is utilized to block the seepage passage allowing the underground water in surrounding rock to flow towards a secondary lining, tunnel freeze-thaw damage is relieved, and water stopping effects are further increased by laying a layer of water stopping plate outside the quick lime layer; a layer of polystyrene board is disposed outside the water stopping plate to reduce the expansion pressure, caused by the size micro-expansion of the quick lime layer during reaction, to the secondary lining; the corresponding design method and the construction flow are provided, the method is applicable to design and construction of tunnel freezing damage preventing projects of seasonally frozen regions, expected protecting requirements can be met, and unnecessary economical waste is avoided.

Description

technical field [0001] The invention relates to a method effectively used for preventing freezing damage of tunnels in seasonally frozen soil regions in the fields of tunnel engineering, frozen soil engineering and protection engineering. technical background [0002] my country is a country with a large frozen soil, ranking third among the world's four major frozen soil countries. The cumulative distribution area of ​​permafrost and seasonal frozen soil reaches 7.29×10 6 km 2 , of which the seasonal permafrost area reaches 5.14×10 6 km 2 (accounting for 54% of the country's land area), the area of ​​seasonal frozen soil with a freezing depth of more than 0.5m and an important impact on the project is 4.46×10 6 km 2 , The area of ​​deep seasonal frozen soil with a freezing depth of more than 1.5m and a serious impact on the project is 3.67×10 6 km 2 . In recent years, my country has increasingly accelerated the construction of high-grade highways, expressways, heavy-d...

AI Technical Summary

Problems solved by technology

However, so far, there is a lack of economically effective methods for preventing frost damage in tunnels in seasonally frozen soil regions, and some of the methods for preventing frost damage from engineering experience in permafrost regions do not meet the actual conditions of "freezing and thawing" in seasonally frozen soils.

At present, since any thermal insulation material is bound to form a balanced and uniform negative temperature field in the surrounding rock near the tunnel - lining - air inside the tunnel - air outside the tunnel in the cold winter of 3 to 6 months, the freezing damage of tunnels in seasonally frozen soil areas The use of "insulation" measures for prevention has little effect, and the cost of antifreeze has increased significantly

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