Sectional steel horizontal enclosure structure and construction method of subway entrance and exit in rocky strata

Abstract

The invention belongs to the technical field of design and construction of traffic engineering of urban rails, and particularly relates to a segmented profile-steel horizontal retaining structure of subway exits and entrances of rock strata and a construction method. The profile-steel horizontal retaining structure comprises concrete roof protection rings, side wall profile steel, side wall anchoring parts, side wall wire-netting shotcrete, pit bottom profile steel, pit bottom wire-netting shotcrete, waterproof layers, bottom plates, side walls, roof plates and foundation pits. The construction method includes the steps of 1, constructing the concrete roof protection ring of the foundation pit at the deepest position; 2, constructing the profile-steel horizontal retaining structure in the process of downward excavation; 3, carrying out excavation to pit bottoms and sealing the bottoms; 4, excavating other adjacent foundation pits in a spaced mode and connecting the foundation pits into a whole; 5, carrying out slope construction on the foundation pit at an opening; and 6, disassembling middle wall structures in the adjacent foundation pits in a segmented mode and building the exits and the entrances through formworks. According to the segmented profile-steel horizontal retaining structure and the construction method, fast open cutting construction of exit and entrance structures can be carried out in urban complex environment and narrow and small space through simple equipment, stratum deformation and stability of the foundation pits can be effectively controlled, the construction speed can be increased, and the building cost of projects can be lowered.

Description

technical field [0001] The invention belongs to the technical field of urban rail transit engineering design and construction, and in particular relates to a profiled steel horizontal enclosure structure and construction method for an open cut section of a subway entrance and exit in a rocky stratum. Background technique [0002] With the development of my country's urban rail transit construction, more and more cities have begun to carry out subway construction, encountering various geological conditions. The geological conditions encountered in most urban subway construction are mainly Quaternary soil layers. At present, there are also many cities with rocky layers, such as Dalian, Chongqing, Qingdao, Xiamen and other cities. The entrances and exits of subway stations generally start construction after the construction of the main structure is completed. In the soil stratum, the entrances and exits of open-cut stations are generally constructed by the open-cut method, and ...

AI Technical Summary

Problems solved by technology

The underground diaphragm wall can only be constructed by milling grooves in the rock formation, which is very expensive and uneconomical; the bored piles need to be impacted successfully, and the construction speed is slow; if the bored piles are excavated by manual blasting, the construction risk is too high

Moreover, the rock formation itself has a certain self-stabilizing ability, and the self-supporting ability of the surrounding rock should be fully utilized during the excavation of the foundation pit. The traditional enclosure structure is very uneconomical.

[0004] At the same time, the diameter of the underground diaphragm wall or hole pile is generally more than 800mm, and the construction machinery occupies a relatively large area.

This is difficult to achieve for station entrances and exits located on narrow roads in central urban areas

In many subway stations, the entrances and exits are very close to existing buildings, and it is basically impossible to construct with traditional enclosure structures; the pipelines around the entrances and exits are generally dense, and reducing the thickness of the enclosure structure may avoid many pipelines

When adopting the traditional enclosure structure to construct the entrance and exit, in many cases, the implementation of the enclosure structure needs to occupy roads and relocate pipelines, which is difficult to coordinate and takes a long time

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