Supporting method for soft broken nonuniform stratum tunnel construction

Abstract

The invention discloses a supporting method for soft broken nonuniform stratum tunnel construction. The supporting method includes the steps that firstly, an arch support is erected in a bottom layer tunnel through steel pipes, and the portion, on the top of the arch support, of the bottom layer tunnel is drilled; secondly, a small pipe roof is constructed on the drilled portion of the arch crown of the arch support; thirdly, during construction of the small pipe roof for supporting, advanced reinforcement treatment is conducted on a top arch of the tunnel through advanced small pipes in a floor staggered mode; fourthly, the tunnel is excavated; fifthly, after the tunnel is excavated, preliminary supporting construction is conducted in time each cycle; sixthly, after excavation and supporting of a tunnel trunk of the tunnel, an inverted arch is constructed and sealed into a loop; and then secondary lining following operation is conducted. The method has the advantages that deformation of tunnel surrounding rocks can be effectively reduced, self-stabilization and seepage prevention capacity of the tunnel is permanently improved, a multifunctional surrounding rock reinforcement region is formed, and safety of tunnel constructors and equipment is guaranteed.

Description

technical field [0001] The invention relates to the technical field of geotechnical engineering, in particular to a support method for tunnel construction in weak and broken uneven stratum. Background technique [0002] Tunnel construction in weak and fragmented uneven strata can easily cause excessive deformation of the surrounding rock of the tunnel, and even rockfall, collapse and other geological disasters, thus endangering the safety of construction workers and damaging production equipment. The support method for tunnel construction in weak and broken uneven stratum is mainly a support method combining small pipe shed support and pre-reinforcement of split-level advance small conduits. However, through the support of small pipe sheds, although the earth pressure overlying on the tunnel face is reduced, the vault and surface settlement are reduced, and the self-stabilizing ability of the surrounding rock is improved, the water-stopping effect is general and the second r...

AI Technical Summary

Problems solved by technology

However, although the support of the small pipe shed reduces the earth pressure on the tunnel face, reduces the settlement of the vault and the surface, and improves the self-stabilization of the surrounding rock, the water-stop effect is general and the second row of pipes is installed due to the vertical overlap. At the same time, although the pre-reinforcement of small conduits in advance can achieve the purpose of pre-reinforcement, anti-seepage, and plugging of tunnel surrounding rock, its reinforcement range is relatively small and the action time is short, which can improve the self-reinforcement of tunnel surrounding rock. The stabilization ability is limited, the effect of controlling the surface settlement is average, and the grouting effect is not uniform, so the reinforcement range cannot be effectively formed, thereby reducing the reliability.

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