Backfill grouting slurry and grouting process with controllable setting time, and grouting device

Abstract

The invention discloses backfill grouting slurry and a grouting process with controllable setting time, and a grouting device. The backfill grouting slurry comprises cement mortar, water glass and a retarder, wherein the mass of the retarder is 1-10% of the mass of cement in the cement mortar, and the addition amount of the water glass is 5-10% of the volume of the cement mortar. The invention further provides the backfill grouting process. The grouting device comprises a first mortar tank, a second mortar tank, a first storage tank and a second storage tank, wherein the second mortar tank communicates with the first mortar tank through a first pipeline and is used for mixing mortar; the first storage tank and the second storage tank respectively communicate with the second mortar tank through a second pipeline and a third pipeline; a backfill grouting pipe is arranged on the second mortar tank; and flow control pumps are respectively arranged on the first pipeline, the second pipelineand the third pipeline. The setting time of the cement mortar is adjusted by adjusting the mixing amount of the water glass and the retarder, and the problems that duct pieces float upwards, an earthsurface sinks and the setting time is too short due to too long setting time of single slurry are solved.

Description

technical field [0001] The invention relates to a grouting slurry, a grouting process and a grouting device, in particular to a back-wall grouting slurry with controllable setting time, a grouting process and a grouting device. Background technique [0002] During the construction of a shield tunnel, grouting behind the wall is an important process for filling the gap at the tail of the shield, preventing surface settlement, and stabilizing the lining segment. However, at present, hard slurry and inert slurry are mostly used for grouting filling, and the coagulation time of the slurry is long. After being injected into the gap of the tail of the shield, the slurry remains in a liquid state for a long time, and the generated buoyancy acts on the segment to cause the segment to float upward. It is not conducive to the stability of the segment; driven by the grouting pressure, it will also flow to the cutter head, which will make the gap in the tail of the shield unrealisticall...

AI Technical Summary

Problems solved by technology

However, at present, hard slurry and inert slurry are mostly used for grouting filling, and the coagulation time of the slurry is long. After being injected into the gap of the tail of the shield, the slurry remains in a liquid state for a long time, and the generated buoyancy acts on the segment to cause the segment to float upward. It is not conducive to the stability of the segment; driven by the grouting pressure, it will also flow to the cutter head, making the gap in the tail of the shield unrealistically filled, and at the same time, it will also cause surface settlement

Moreover, in the soil layer with a large permeability coefficient, the slurry will be lost during the condensation process, resulting in the formation of a cavity between the top of the segment and the soil, and in the soil layer with abundant interstitial water, water seepage will occur even when the subway or tunnel is in operation In other cases, the construction unit needs to repeatedly perform secondary grouting, resulting in a waste of manpower, material resources and financial resources.

[0003] Cement-sodium silicate double-liquid slurry is an instant-setting type of slurry, which solidifies immediately after injection. Although it can solve the above-mentioned problem of long slurry flow time, due to the lack of current grouting management methods, double-liquid grouting is prone to pipe plugging and grout hoops. The phenomenon that the tail of the shield is stuck seriously affects the construction efficiency

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