Two-step inverted arch fast closed tunnel support structure and construction method thereof

Abstract

The invention provides a two-step inverted arch fast closed tunnel support structure and a construction method thereof. The two-step inverted arch fast closed tunnel support structure comprises a first layer initial support, a second layer initial support, a waterproof layer and a secondary lining from the outside to the inside. The first layer initial support includes a first layer initial upperstep support and a first layer initial lower step support, and the second layer initial support includes a second layer initial upper step support and a second layer lower step support. The construction method comprises the following steps that an upper step advanced support and upper step advanced reinforcement anchor rods are installed; an upper step tunnel body is excavated; the first layer upper step support is installed; a lower step tunnel body is excavated; the first layer initial lower step support is installed; side wall long anchor rods of a lower step and tunnel bottom long anchor rods are installing; the second layer lower step support are installed; the side wall long anchor rods of an upper step and arch crown long anchor rods are installed; the second layer initial upper step support is installed; and inverted arches and the secondary lining are poured. The two-step inverted arch fast closed tunnel support structure and the construction method thereof can reduce the safety risk during the construction process, and are safe and fast.

Description

technical field [0001] The invention relates to the technical field of tunnel construction, in particular to a two-step and inverted arch fast-closing tunnel support structure and a construction method thereof. Background technique [0002] A tunnel is an engineering structure built underground and is widely used in fields such as transportation, mining, water conservancy, and national defense. The current tunnel is usually constructed using the new Austrian method, and the support structure is a composite lining structure, including the vault, invert and side walls on both sides along the tunnel ring direction, including the outer primary support and the inner secondary support along the tunnel radial direction. Secondary lining and waterproofing layer between primary support and secondary lining. [0003] With the rapid development of tunnels and underground engineering in Southwest my country, the number of mountain railway tunnels and extra-long tunnels has gradually in...

AI Technical Summary

Problems solved by technology

The support structure in the prior art adopts the method of directly sticking to the surface of the tunnel passage to establish a rigid primary support, so that under the action of high stress in the rock stratum around the tunnel passage, the concrete in the primary support often cracks, peels off, and steel The arch frame is distorted and deformed; the deformation of the steel arch frame will occupy the space for the next secondary lining, making it impossible to continue to implement the secondary lining, so that the existing rigid primary support has to be demolished and a new rigid primary support must be re-established

This not only greatly increases the project cost and construction risk, but also greatly prolongs the construction period.

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