Bentonite grouting method for construction of shield tunnel

Abstract

The invention discloses a bentonite grouting method for construction of a shield tunnel. The bentonite grouting method comprises the following steps of: 1, drilling radial grouting holes: drilling the radial grouting holes on a central line of the upper part of a shield body of a shielding machine; 2, mounting a grouting pipe and a pipe control valve; 3, mounting grouting connecting pipes and a grouting device; and 4, constructing the shield tunnel: shielding by the shielding machine; when the practical pressure of the interior of a soil bin is smaller than the pressure of the interior of the soil bin during regular shielding construction of the shielding machine, opening the pipe control valve, and injecting Na-based bentonite slurry towards the outside of the shield body of the shielding machine through the grouting device till the practical pressure of the interior of the soil bin is equal to the pressure of the interior of the soil bin during regular shielding construction of the shielding machine, and closing the pipe control valve. The bentonite grouting method disclosed by the invention has the advantages of reasonable design, simple construction steps, convenience for realizing, low construction cost, good construction effect, and capabilities of quickly supplementing pressure loss of the soil bin during construction of the shielding machine, keeping the pressure of the soil bin stable, and effectively guaranteeing settlement safety of an upper stratum of a tunnel to be constructed.

Description

technical field [0001] The invention belongs to the technical field of shield tunnel construction, and in particular relates to a bentonite grouting method for shield tunnel construction. Background technique [0002] At present, major cities in my country are building and planning their own subway construction. In a city, the subway network is often composed of multiple lines. It is unavoidable that all of these indicate that there will be a large number of cross tunnels and underpass buildings (structures) in the future. [0003] During the construction of cross tunnels, especially in the construction of new shield tunnels passing under existing lines in soft ground, how to ensure the settlement safety of the existing lines becomes the key to the success of the underpassing. Nowadays, when constructing intersecting tunnels in China, the method of reinforcing the soil between the two intersecting tunnels is generally adopted to ensure the settlement safety of the existing l...

AI Technical Summary

Problems solved by technology

However, for the construction of new shield tunnels passing through the existing operating line at small intervals in the soft soil layer, it is difficult to reinforce the interlayer soil, and the reinforcement construction may destroy the stability of the interlayer soil itself, thereby increasing the existing The settlement of the running line increases the operational risk of the existing line

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