Tunnel excavation construction method

Abstract

The invention relates to a tunnel excavation construction method; an excavated tunnel comprises a first main line tunnel conventional segment, a first main line tunnel expansion segment, a second main line tunnel conventional segment, a second main line tunnel expansion section and a maximum cross section tunnel section; the method comprises the following steps of: firstly excavating the maximum cross section tunnel section, and then excavating in a transitional way from a big cross section to a smaller cross section of the maximum cross section tunnel segment, thereby realizing the excavation construction on a subway interval tunnel containing a junction line and a stop line in a big to small necked-down section mode. The method has the beneficial technical effects: (1) only one verticalshaft needs to be arranged, and the construction workload is less; (2) the overall process is in a transitional way from the big cross section to the smaller cross section, and the reverse expansion construction is not needed so as to avoid the risk of expansion excavation construction; (3) the excavation construction is carried out on the subway interval tunnel containing the junction line and the stop line in a big to small necked-down section mode, a roundabout pilot tunnel method is avoided from being used, the working procedures are simple, and the temporary first-lining workload is small.

Description

technical field [0001] The invention relates to a subway tunnel excavation construction method, in particular to an excavation construction method for a subway interval tunnel including a crossing line and a stop line. Background technique [0002] The main methods currently used in the excavation construction of subway tunnels include the shield method and the shallow buried method. The so-called shallow buried underground excavation method refers to a method of underground excavation construction of various types of underground caverns near the surface. The shallow burial and underground excavation method follows the basic principle of the new Austrian method. The primary support bears all the basic design loads, and the secondary lining is used as a safety reserve; the primary support and secondary lining jointly bear special loads. When designing and constructing with the shallow buried excavation method, various auxiliary construction methods are adopted at the same ti...

AI Technical Summary

Problems solved by technology

[0017] When using the above construction methods for tunnel excavation, although the construction of the cross passage is simple, its disadvantages include: (1) It is necessary to set up multiple vertical shafts, and the construction workload is relatively large

(2) It is difficult to construct a variable section with a gradual transition from a small section to a large section, and there are many unfavorable working conditions such as climbing and expanding excavations, breaking walls, and reverse-sequence construction in the circuitous pilot pit method

(3) A variety of construction methods are used, basically covering all construction methods such as the cross middle partition method (CRD method), glasses construction method, and middle hole method; and the process conversion between each section is complicated, and the amount of temporary initial lining is large

(4) Gradually transition from a small section to a large section, especially when reaching the tunnel section with the largest section, the section changes drastically, thus increasing the risk of collapse

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