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

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 ba