Top-down construction method of large underground structure outer wall

Abstract

The invention discloses a top-down construction method of a large underground structure outer wall, comprising the following steps: constructing a supporting pile; borrowing earth; binding a first section of outer wall and ring beam reinforcing steel bars, wherein the ring beam reinforcing steel bars are respectively fixedly connected with reinforcing steel bars in the first section of outer walland the reinforcing steel bars in the supporting piles; raising templates; pouring concrete, wherein the first section of outer wall, the ring beam and the supporting piles are integrated as a whole;and repeating the construction of borrowing earth, binding reinforcing steel bars, raising templates, pouring concrete until the bottom surface of the last section of outer wall reaches the designed elevation. The adoption of a pile hanging technique in the invention ensures safe construction, the adoption of a double anti-leakage technique ensures no leakage inside the outer wall, the adoption ofa fast molding technique accelerates the program progress, and the application of sizing steel templates ensures the appearance quality of the concrete thereby achieving a good effect.

Description

technical field [0001] The invention relates to a reverse construction method, in particular to a reverse construction method for the outer wall of a large underground structure. Background technique [0002] The top-down method is a construction method in which the underground structure is supported by rigid columns or piles, and the soil is excavated from top to bottom and alternately constructed to complete the underground structure. It can improve the safety of retaining support, shorten the overall construction period, and reduce the impact on buildings in surrounding areas. Therefore, the number of projects using the reverse method has been increasing, and the scale of the project has gradually expanded from small and medium-sized projects to large-scale projects. [0003] At present, the caisson method is usually used for the construction of the outer wall of large-scale underground structures. The first step: make the first section of the outer wall at the predeterm...

AI Technical Summary

Problems solved by technology

The disadvantages of the above-mentioned caisson method are: (1) the settlement of the outer wall is not easy to control, the position of the underground structure is easily deflected, and the verticality deviation is relatively large, which affects the position accuracy of the underground structure; (2) it cannot be applied to all geological conditions, such as : Geology with rock layers, because the geological conditions are more complicated, the friction force outside the outer wall is large, and the settlement of the outer wall cannot be completed; (3) when making the outer wall, the inner and outer sides need to support the formwork at the same time, and the workload is large

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