A full-section construction method of pipe-curtain underground excavation for shallow-buried tunnels under complex environmental conditions

Abstract

The present invention proposes a full-section construction method of pipe-curtain excavation for shallow-buried tunnels under complex environmental conditions. By combining the pipe-curtain excavation technology with shallow-buried tunnel construction safety and settlement control technology, one or more of the following Measures to be taken: (1) Minimize the range of the bottom-picking distance of each inverted arch, the space distance between the bottom-picking process and the tunnel excavation face, and the space distance between the second lining and the tunnel excavation face; (3) When necessary, under the protection of the super-strong pipe curtain, the face of the tunnel excavation is reinforced to realize the full-section excavation of the face of the tunnel excavation. stability. Due to the excavation of the full section and the shortening of the distance of each process as much as possible, the present invention effectively shortens the distance between the second lining and the operation face, and the ring and longitudinal bearing jointly formed by the second lining, the primary support, the soil mass in front of the operation face and the pipe curtain Compared with the "shallow burial and underground excavation method", the force system has better safety guarantee and surface settlement control effect.

Description

technical field [0001] The invention relates to a tunnel pipe curtain full-section construction method, in particular to a shallow-buried tunnel pipe curtain full-section construction method under complex environmental conditions. Background technique [0002] The East Ring Line of Chongqing Railway Hub is located around the city, and the environmental conditions are very complicated. Many places pass through the expressway, such as the new Baiyangwan double-track tunnel with a 4m clear distance under the cutting of the Chongqing Ring Expressway; Maoyakou and Qiaozibao No. 2 single-track tunnel Parallel 2~3m clear distance under the filling subgrade of Yuyi Expressway; Jinyu single-track tunnel under 7m clear distance under the filling subgrade of Jinyu Avenue; Jinshan double-line tunnel HMDK14+540~+595 section near Jinshan Avenue filling subgrade Pass through the 20m thick waste slag body; pass through the area of ​​Zhaojiaxi Interchange under the 10m clear distance at the ...

AI Technical Summary

Problems solved by technology

However, due to its advanced support, pipe sheds or small conduits are generally used, and the tunnel face is generally excavated in multiple sections. The distance between the second lining and the tunnel face is relatively long. Under shallow buried complex environmental conditions, due to the extremely high requirements for surface settlement control, the traditional It is difficult to meet the requirements of tunnel construction safety and surface subsidence control in the construction process of the shallow buried underground excavation method.

[0007] (3) At present, in the application cases of pipe curtain underground excavation tunnels, there are no special requirements for the timing of the secondary lining, and the role of the secondary lining is basically not considered in the control of surface settlement; the tunnel face basically adopts multi-part excavation, and the secondary The sub-face distance is long, and the long-distance excavation is carried out under the action of the primary support, and the construction safety and the effect of surface settlement control are not good

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