Three-liquid backfilling construction method and system in a shield tunnel

Abstract

The invention provides a three-liquid backfilling construction method and system in a shield tunnel, and the method comprises the steps: respectively injecting mortar, a foaming agent solution and a water glass solution into corresponding positions according to different times and positions, preparing air mortar at the injection positions, and immediately mixing the air mortar with the water glasssolution and injecting the mixture into the tail part of the shield tunnel. And the existing problems can be effectively solved, so that the effect after grouting is remarkably improved.

Description

technical field [0001] The disclosure relates to a construction method and system for post-filling of three liquid walls in a shield tunnel. Background technique [0002] The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art. [0003] The shield tunneling method is widely used in the construction of urban subways and underwater tunnels because of its many advantages: However, the shield tunneling method will inevitably cause disturbance to the surrounding strata and cause surface subsidence. The key to controlling the surface settlement of the shield tail is to effectively fill the shield tail gap, and the filling of the shield tail gap needs to be realized by grouting behind the wall. [0004] In actual engineering, the mixed slurry of cement and water glass is often used as the grouting material behind the wall, so that the slurry has the advantages of low viscosity, good groutabi...

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Problems solved by technology

[0005] This kind of three-liquid grouting construction usually adopts the method of using air foaming agent, adding it to the mortar to prepare air mortar, adding water glass solution, and finally pumping the mixed solution to the injection point through the pump for post-wall injection. grout, and this traditional water glass type air grout has many fatal disadvantages: (1) Due to the long-distance pressure supply, material separation is prone to occur under air erosion

(2) The longer the mixed slurry exists in the pipeline, the air will be lost to a certain extent and the air bubbles will become more and more fragile

(3) The water glass itself will react with the components in the air, and the loss of air will be very large, thus affecting the consolidation effect after grouting

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