Structure system for reducing tunnel lining frost heaving force in cold region

Abstract

The invention discloses a structure system for reducing tunnel lining frost heaving force in a cold region and belongs to the field of tunneling freezing damage prevention in the cold region. The structure system sequentially comprises tunnel primary lining concrete, a composite geotechnical cloth water-proof layer, a buffering layer and a secondary lining from the inside to the outside. The buffering layer is composed of a polyethylene foam lining and fiber-reinforced foam concrete. The polyethylene foam lining is paved and fixed on the surface of the water-proof layer in a close bonding mode. The fiber-reinforced foam concrete is poured outside the polyethylene foam lining. When underground water is frozen to become ice, the buffering layer structure can have a heat preservation effect and relieve the frosting of the underground water. When the underground water is frozen, the buffering layer has a buffering effect on the frost heaving force exerted on the secondary lining structure through self-deformation so as to reduce stress and deformation of the secondary lining, prevent cracking and achieve the purpose of preventing freezing damage to a tunnel structure.

Description

technical field [0001] The invention relates to the field of frost damage resistance of tunnel engineering in cold regions. Background technique [0002] At present, freezing damage to tunnels in cold regions in my country is very serious, often causing traffic accidents, and causing damage or even scrapping of tunnel structures. Therefore, freezing damage at tunnel entrances in cold regions is an urgent problem to be solved. One of the important causes of freezing damage at tunnel entrances in cold regions is that the frost-heaving force caused by surrounding rock and groundwater acts on the lining structure, resulting in cracking and failure of the lining. [0003] Existing antifreeze technologies for tunnels in cold regions mainly include heating method, anti-cold door and heat insulation method, among which the main method to solve the problem of frost heaving force is to lay heat insulation layer structure. However, in the permafrost region, when the absolute value of ...

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Problems solved by technology

However, in the permafrost region, when the absolute value of the accumulated coldness of the year is greater than the annual accumulated heat, the formation of the frozen layer cannot be prevented; on the other hand, due to the low strength and elastic modulus of the insulation material, When compressed and deformed, the heat insulation layer will be damaged under pressure, thus losing the function of antifreeze and heat preservation

Moreover, since it is difficult to achieve the effect of smooth blasting during tunnel construction, there are inevitably pores or cavities between the primary lining concrete and the secondary lining structure. Under the action of repeated freeze-thaw cycles, it is difficult to eliminate or reduce the damage caused by groundwater freezing with thermal insulation and antifreeze technology. The frost heaving force generated, so it is difficult to guarantee its durability and long-term service performance, and it is impossible to prevent the frost damage caused by the frost heaving force

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