Tie-rod structure and construction method of tunnel cover excavation method of soil arch tire formwork in mountainous area

Abstract

The invention discloses a formwork tie bar structure of a soil arch mould in a cover-excavation method for a mountain highway tunnel, and a construction method thereof, and belongs to the field of construction adopting a cover-excavation method for a mountain highway tunnel. The formwork tie bar structure of the soil arch mould mainly comprises a cover arch formwork which is arranged on the soil arch mould and composed of a steel formwork, a wood formwork, a steel formwork lacing bar, a lacing bar sleeve and a channel steel backing plate, and two pairs of upper tie bars and lower tie bars which are arranged at the bottoms of the steel formwork and the wood formwork, wherein cover arch concrete is formed between the wood formwork and the steel formwork through pouring, and then lining concrete is poured secondarily. The formwork tie bar structure of the soil arch mould in the cover-excavation method for the mountain highway tunnel has the advantages of being simple in structure, convenient to use, safe and reliable, low in expense, capable of repeatedly utilizing construction materials, and the like; the structure is beneficial to reducing the project quantity of tunnel slope excavation of the construction adopting the cover-excavation method, and saving a spoil ground in conjunction with the corresponding construction method; and the structure further has an effect of energy conservation and emission reduction, and has remarkable economic benefits and social benefits.

Description

technical field [0001] The invention relates to the construction field of road tunnel cover excavation in mountainous areas, in particular to an earth arch tire formwork tie rod structure and a construction method thereof for road tunnel cover excavation in mountainous areas. Background technique [0002] The road tunnel cover excavation method is to excavate the ground down to a certain depth, then seal the top, and the rest of the substructure is constructed under the closed top cover. Highway tunnels in mountainous areas need to pass through valleys and under mountains. Due to the shallow cover layer in valleys and great changes in geological conditions, the construction difficulty of valley tunnels is generally greater than that of tunnels under mountains. The covering layer of the valley often encountered in the project is relatively thin, and the height of the tunnel part is the soil layer with poor geology, and the weathered rock layer below is the weathered rock laye...

AI Technical Summary

Problems solved by technology

The covering layer of the valley often encountered in the project is relatively thin, and the height of the tunnel part is the soil layer with poor geology, and the weathered rock layer below is the weathered rock layer with better geology. The patent No. 201110451019.4 is "Construction method of soil tire mold by cover-excavation method", which proposes a soil tire mold, that is, a soil arch tire construction method. The overall stability of the arched tire and the arched steel formwork, such as using steel members to support the arched formwork of the soil arched tire on both sides of the excavated slope, the deformation of the slope soil is not easy to control, and the overall stability of the soil arched tire and the arched steel formwork is also It is difficult to guarantee, and there is a potential safety hazard; and the disclosed Chinese patent No. 201420739014.0 is "Comprehensive Support Structure of Mountain Tunnel Pile Arch Cover Excavation Method", which adopts two rows of bored piles parallel to each other. The cost is even higher, and It is also difficult to reuse construction materials

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