Large-span single-arch subway station, large-section tunnel, underground structure and construction method thereof

Abstract

The invention belongs to the technical field of underground excavation construction of large underground structures, and discloses a large-span single-arch subway station, a large-section tunnel, an underground structure and a construction method of the large-span single-arch subway station. The construction method comprises the steps that a shield is adopted to construct two longitudinal tunnels along arch feet of a station, reinforced concrete strip-shaped foundations are poured in the tunnels in a full-length mode, and arch rings and connecting steel bars of inverted arches are reserved in the strip-shaped foundations; longitudinal pipe roofs are arranged along the outer contour of the arch ring of the station, and concrete is poured into the pipe roofs; part of pipe pieces are broken at certain intervals in the shield tunnel, the pipe roofs are perpendicular to the longitudinal pipe roofs to excavate annular guide holes, formworks are erected in the annular guide holes to construct arch ring beams, the backs of the arch ring beams are tightly attached to and abut against the pipe roofs, and arch feet and strip-shaped foundations in the shield tunnel are connected into a whole; an upper-layer soil body of the station is excavated, and inner arch ring plates between arch ring beams are constructed; and longitudinally excavating a lower-layer soil body of the station section by section and constructing an inverted arch structure until the station is through. The method is simple in process, low in construction risk, high in mechanical operation degree and low in engineering cost.

Description

technical field [0001] The invention belongs to the technical field of underground excavation and construction of large-scale underground structures, and particularly relates to a large-span single-arch subway station, a large-section tunnel, an underground structure and a construction method thereof. Background technique [0002] The traditional underground excavation methods for large underground structures mainly include the middle hole method, the side hole method, the column hole method and the hole pile method. This kind of traditional underground excavation method is essentially a shallow buried underground excavation subsection excavation method, that is, the large section is decomposed into small sections, and the subsections are excavated and supported by small sections to build a large section underground structure. This kind of method has the following problems: (1) Multiple excavation disturbs the soil layer greatly, which is not conducive to the stability of th...

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Problems solved by technology

This type of method has the following problems: (1) Multiple excavations greatly disturb the soil layer, which is not conducive to the stability of the soil layer. The ground subsidence is large, and the construction risk is huge; (2) Due to the large number of working faces, the mutual interference is large, the organization and coordination are difficult, the work efficiency is low, and the construction period is long; (3) Generally, additional auxiliary measures are required, and the initial support and the main structure There is a secondary force conversion between them, the waste of the initial support is large, and the project cost is high

Different from the "honeycomb arch" technology, the pipe-curtain pre-construction method uses large-diameter steel pipes to replace the side wall pilot pits, and the arch foot soil is reinforced by grouting in the bottom steel pipes. The large-span single-arch station project where groundwater is difficult to handle, but this construction method has the following disadvantages: (1) Large-scale connected cutting, welding and incision support operations, as well as formwork, steel bar binding and other operations are carried out in a steel pipe with a limi

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