Primary support structure of tunnel steel pipe arches and support method of primary support structure

Abstract

The invention relates to a primary support structure of tunnel steel pipe arches. The structure comprises a plurality of sections of steel pipe arches and reinforcing meshes, wherein the steel pipe arches are laid on surrounding rock of a tunnel face and connected together through connecting reinforcing steel bars, and the reinforcing meshes are arranged on the surface of the surrounding rock of afree face. Each section of the steel pipe arch is formed by connecting a plurality of seamless steel pipes through sleeving steel bars; a pair of foot locking anchor pipes is arranged at each of thearch crown part, the arch waist part and the arch foot part in each steel pipe arch; the reinforcing meshes are arranged on the steel pipe arches; and primary lining sprayed concrete is arranged on the steel pipe arches, the reinforcing meshes, the connecting reinforcing steel bars and the foot locking anchor pipes, and a waterproof plate and a secondary lining are sequentially arranged on the primary lining sprayed concrete. The invention further discloses a support method of the support structure. The primary support structure has the field practical characteristics of rapidness, high efficiency, simplicity and easiness in operation, and is a supplement for the primary support parameters of the III-grade and IV-grade surrounding rocks of the rock tunnel.

Description

technical field [0001] The invention relates to the technical field of highway engineering and railway engineering tunnel construction, in particular to a tunnel steel pipe arch primary support structure and a support method thereof. Background technique [0002] With the continuous development of social economy, according to the needs of road development in our country, the grade of roads has been continuously improved, and there are more and more long road tunnels passing through mountainous areas. The buried depth of the tunnels has greatly increased the difficulty of designing geological surveys. Overall, the design depth of tunnel support is insufficient, the design support situation does not match the actual excavation surrounding rock conditions on site, the support parameters are too strong, resulting in project waste, and the support parameters are too weak to ensure structural quality and safety. So how to adjust the initial support parameters in this case is parti...

AI Technical Summary

Problems solved by technology

The initial support method of rocky mountain tunnels mostly adopts steel frame + anchor shotcrete initial support. According to the construction principle of the new Austrian method, the bearing capacity of the surrounding rock should be exerted. The classification of the surrounding rock determines the division of the lining type and parameters. However, when the surrounding rock is between grade IV and grade III, there is no initial support parameter that can meet the strength and safety requirements, save energy and reduce cost waste, especially in tunnels with hard rock, well-developed joints and cracks, and broken lithological structures. In some cases, the sprayed anchors of the hanging nets will partially collapse, and the steel frame + anchor sprayed support is used and the support is too strong, resulting in a waste of engineering costs

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