Tunnel construction method for passing through weak broken surrounding rock

Abstract

The invention discloses a tunnel construction method for passing through weak broken surrounding rock. A supporting structure of a constructed tunnel comprises a tunnel primary supporting structure for carrying out primary supporting on the constructed tunnel and a tunnel secondary lining which is arranged on the inner side of the tunnel primary supporting structure and used for carrying out secondary supporting on the constructed tunnel. The method comprises the steps that 1, an upper pilot tunnel is excavated and supported; 2, a middle pilot tunnel is excavated and supported; 3, a lower pilot tunnel is excavated and supported; and 4, tunnel secondary lining construction is carried out. According to the tunnel construction method, the constructed tunnel is anchored through expandable anchoring devices, and the overall stability of the constructed tunnel is improved; and the expandable anchoring devices are arranged at the bottom and the top of a steel arch frame in the upper pilot tunnel correspondingly, the expandable anchoring devices are arranged at the bottom and the middle of a steel arch frame in the middle pilot tunnel correspondingly, and therefore the supporting effect of primary supporting in the constructed tunnel is improved, and the overall stability of the constructed tunnel is enhanced.

Description

technical field [0001] The invention belongs to the technical field of tunnel engineering construction, and in particular relates to a tunnel construction method for passing through weak and broken surrounding rocks. Background technique [0002] Due to the development of fractures in the weak and broken surrounding rock, the structural planes are intertwined and randomly distributed without obvious directionality. To a certain extent, it can be regarded as an isotropic homogeneous continuum. The overall compressive strength of the weak and broken surrounding rock is low. After excavation, the stability of the surrounding rock is poor, and the deformation is relatively large after excavation disturbance, which is very easy to lose stability and damage. Tunnel excavation on such strata can easily cause large uneven settlement. In addition, after the tunnel lining is constructed, the surrounding pressure will also produce creep or rheological deformation under the action of i...

AI Technical Summary

Problems solved by technology

[0002] Due to the development of fractures in the weak and broken surrounding rock, the structural planes are intertwined and randomly distributed without obvious directionality. To a certain extent, it can be regarded as an isotropic homogeneous continuum. The overall compressive strength of the weak and broken surrounding rock is low. The stability of the surrounding rock is poor after the excavation of the chamber, and the deformation is large after the excavation is disturbed, and it is very easy to lose stability and damage

Excavation of tunnels on such strata is very likely to cause large uneven settlement

In addition, after the tunnel lining is constructed, the surrounding pressure will also produce creep or rheological deformation under the action of in-situ stress during the operation period, resulting in large deformation and instability of the lining and other support systems.

At present, the problem of large deformation of tunnels under the condition of soft and broken ground is a key problem in tunnel construction, which brings great challenges to underground engineering construction and seriously restricts the safe and high-speed development of urban rail transit industry.

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