Reversed construction method for expanding and excavating stations on sectional shield tunnel foundations of subways

Abstract

The invention discloses a reversed construction method for expanding and excavating stations on sectional shield tunnel foundations of subways. The expanded and excavated stations are simply supported frame wall column type double-layer subway stations in structural forms. The reversed construction method includes retaining soil and water by the aid of piles in rows and waterproof curtains or underground diaphragm walls, and resisting lateral deformation of soil mass; excavating the soil mass between openings of parallel shield tunnel segments and constructing cross passages; grouting and reinforcing the soil mass above tunnels, building foundation pit excavation supporting structures and short supporting piles of station bodies and connecting the tops of the foundation pit excavation supporting structures and the short supporting piles with the outer piles in the rows or the outer underground diaphragm walls by connecting beams; constructing the structures of the station bodies by the aid of cover and excavation top down processes, filling the station bodies with the soil mass and recovering road surfaces. Foundation pit slopes can be supported by the aid of composite soil nailing supporting technologies in excavation procedures. The reversed construction method has the advantages that the reversed construction method is reasonable and feasible, is high in operability and has important engineering application value and an important development prospect, and huge economic, social and environmental benefits can be brought by application of the reversed construction method.

Description

technical field [0001] The invention relates to a structure for expanding and digging a station on the basis of a shield tunnel in a subway section and a reverse construction method thereof, belonging to the technical field of rail transit construction. Background technique [0002] Among the many subway construction methods, the "shield tunneling method" has been more and more widely used in subway construction because of its high construction safety, fast construction speed, and relatively small impact on the surrounding environment. However, in the past construction of the interval shield method in China, the use of shields was limited to the construction of interval tunnels with a simple and single cross-section. The current shield well is hoisted out, then transferred to another shield well, and then the shield machine is reassembled for construction; or the station is expanded and excavated in advance to expand the width and bottom of the station, and then the shield m...

AI Technical Summary

Problems solved by technology

It is mainly used to solve the problem of section shield tunneling (referring to the shield equipment used for subway section tunnels with a diameter of about 6m, and the single shield tunnel formed by its excavation to expand the subway station cannot be used to expand the subway station) under the current conditions. Too many propulsion operations and inefficient use of shield equipment

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