Secondary starting method for shield in single-hole single-line underground excavation tunnel

Abstract

The invention provides a secondary starting method for a shield in a single-hole single-line underground excavation tunnel. The method comprises the steps that 1, the single-hole single-line tunnel isconstructed through an underground excavation method; 2, stratum grouting reinforcement and advanced large pipe shed supporting are conducted on the end of secondary starting of the shield; 3, a mainmachine of a shield tunneling machine is pushed to pass through an underground excavation section in an air-pushing mode; 4, a reinforced concrete counter-force ring is constructed on the inner edgeof a hole body of the underground excavation section at a certain distance behind the main machine of the shield tunneling machine, shield tunneling is prepared to start with the reinforced concrete counter-force ring as a supporting point, and shield segments are spliced; and 5, the main machine of the shield tunneling machine conducts tunneling, splicing of the shield segments of the undergroundexcavation section is completed, the normal tunneling state is started, and secondary starting is completed. Accordingly, the tunnel section space enlarged by passing of the shield in the air-pushingmode is utilized, the reinforced concrete counter-force ring is poured on a secondary lining of the tunnel, the problem of arrangement of the supporting point of secondary starting of the shield in anarrow space is solved, the application range is wide, and continuous tunneling of a shield section is guaranteed.

Description

technical field [0001] The present invention relates to the technical field of urban rail transit, and in particular to a method for the second initiation of shield tunneling in a single-hole single-line underground excavation tunnel, which solves the problem of shield tunneling passing through the excavation section and carrying out the second initiation of the shield in a narrow space . Background technique [0002] With the rapid development of urban construction, the urban space is becoming more and more tense, and the shield sections of urban rail transit projects often pass through various buildings (structures), such as passing through existing rail transit stations and sections, municipal tunnels, and underground comprehensive tunnels. Corridor etc. It is common for section tunnels to pass through the above-mentioned buildings (structures) at a short distance (less than 0.5 times the excavation width, or even zero distance). Generally, the underground excavation met...

AI Technical Summary

Problems solved by technology

It is common for section tunnels to pass through the above-mentioned buildings (structures) at a short distance (less than 0.5 times the excavation width, or even zero distance). Generally, the underground excavation method with more flexible auxiliary measures is used for construction, which will lead to local dark tunnels in the shield section. Excavation of sections makes the shield section discontinuous, resulting in the problem of adding a shield starting shaft or a second starting of the shield tunnel in the underground excavation

Adding shield tunneling wells can solve the above problems, but the investment is relatively large, increasing the investment in the shield tunneling section will reduce the advantages of the shield tunneling method and weaken the economic benefits

In addition, according to the conventional shield tunneling, it is necessary to increase the cross-section of the underground excavation section, and install facilities such as shield reaction force frames, which also need to increase investment

In addition, due to the enlarged excavation section of the underground excavation section, the construction risk is also increased

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