An open-cut construction method for station expansion and excavation on the basis of shield tunnels in subway intervals

Abstract

An open excavation construction method for expanding excavation of a station on a metro interzone shield tunnel foundation method includes the steps that uplift piles, wall columns, a base plate, a middle stand column foundation and transverse supporting beams between the wall columns are constructed in a transverse channel, wherein the base plate is connected with the bottoms of the wall columns, water prevention treatment is conducted, and the wall columns and duct pieces are connected, so that a sealed stress system is formed; soil over the tunnel is subjected to grouting reinforcement, an excavation retaining structure of a station body foundation bit is built, and the top end of the structure is connected with an external campshed or an underground diaphragm wall through a connection beam; slopes are supported through a composite soil nailing supporting technology, foot locking supports are erected at the pile foots, after excavation is conducted on the bottom of a foundation pit, residual duct pieces are removed, connection beams between the wall columns are constructed, and the connection beams are firmly connected with the duct pieces; the transverse support system is constructed. The method is reasonable, feasible and high in maneuverability. By means of application of the method, great economic benefits, social benefits and environmental benefits are achieved. The method has significant engineering application value and development prospects.

Description

technical field [0001] The invention relates to a structure for excavating a station on the basis of a shield tunnel in a subway section and an open-cut 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 machine is...

AI Technical Summary

Problems solved by technology

This method is mainly used to solve the construction of tunnel extension subway stations under the current conditions of the tunnel extension (the diameter of the shield equipment used for subway interval tunnels is about 6m, and it is impossible to use the single shield tunnel formed by its excavation to expand the subway station) There are too many propulsion operations in the middle and Africa, and the problem of low efficiency in the use of shield equipment

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