Method for construction of sprayed steel fiber reinforced concrete in sandy surrounding rock

Abstract

The invention relates to a method for construction of sprayed steel fiber reinforced concrete in sandy surrounding rock. The method comprises the steps of arranging a pre-support advanced grouting ductile on an excavation face, conducting hand excavation of tunnel sandy soil, assembling tunnel grid steel frames, arranging main reinforcing meshes according to design requirements between the grid steel frames along the outer arcs of the steel frames, arranging auxiliary steel meshes on the inner sides of the main reinforcing meshes, and spraying steel fiber reinforced concrete. By additionally arranging a layer of auxiliary steel mesh piece on the inner side of each main reinforcing mesh, effective bonding between sprayed steel fiber reinforced concrete and sandy surrounding rock is guaranteed, the rebound rate of sprayed steel fiber reinforced concrete is reduced to be about 10%, and raw materials are saved; meanwhile, wind pressure is adjusted and controlled reasonably, the compactness of sprayed steel fiber reinforced concrete is ensured, engineering construction quality is guaranteed, the requirement for design indexes of tunnel first lining engineering is met, and construction efficiency is improved.

Description

technical field [0001] The invention relates to a tunnel construction method, in particular to a construction method of spraying steel fiber concrete in sandy soil surrounding rocks. Background technique [0002] Because the sandy soil is mainly composed of 0.075-2mm particles, there is no cohesive force between the particles, and the nature is loose. When constructing a spray tunnel in the sandy soil layer for the initial lining of steel fiber concrete, it is easy to cause a large amount of steel fiber concrete. It will fall off and cause varying degrees of damage to the sandy soil surrounding rock, which cannot meet the quality requirements of the shotcrete for the initial lining of the tunnel. Therefore, effective methods must be adopted, which can not only meet the compactness requirements of the shotcrete steel fiber concrete, but also realize the sprayed concrete and sand. Reliable bonding of soil and surrounding rock, reducing material loss. Contents of the inventio...

AI Technical Summary

Problems solved by technology

[0002] Because the sandy soil is mainly composed of 0.075-2mm particles, there is no cohesive force between the particles, and the nature is loose. When constructing a spray tunnel in the sandy soil layer for the initial lining of steel fiber concrete, it is easy to cause a large amount of steel fiber concrete. It will fall off and cause varying degrees of damage to the sandy soil surrounding rock, which cannot meet the quality requirements of the shotcrete for the initial lining of the tunnel. Therefore, effective methods must be adopted to meet the compactness requirements of the shotcrete and sand Reliable bonding of soil and surrounding rock, reducing material loss

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