Shield synchronous grouting material composite admixture

Abstract

The invention discloses a composite admixture for shield synchronous grouting material. Its raw material composition, in terms of mass percentage, includes: 10-20% of a coagulant, 10-20% of a retarder, and 40-50% of a high-efficiency coagulant. Water reducing agent, 10-20% tackifier, 1-5% defoamer, 1-5% plastic expansion agent. The present invention has the advantages of realizing adjustable coagulation time under the premise of no need to change equipment and pipelines in the environment of high-pressure water-rich strata, small loss of work performance within the coagulation time, high water resistance and dispersion, efficient filling and rapid coagulation. .

Description

technical field [0001] The invention relates to the field of building materials. More specifically, the invention relates to a composite admixture for shield synchronous grouting materials. Background technique [0002] The synchronous grouting technology is that when the shield is advanced to the end of the shield and the segment is separated from the segment, an over-excavated gap appears on the back of the segment. In order to avoid deformation of the ground and cause destructive effects on adjacent structures, the After the tail of the shield is detached, it is a construction method of filling the back of the segment with consolidating grout. The main purpose of synchronous grouting is: (1) to fill the gap in the shield tail building in time, support the rock mass around the segment, and effectively control the surface settlement; (2) ensure the early stability of the segment lining and the sealing of the gap, and prevent the (3) As the first line of defense for lining...

AI Technical Summary

Problems solved by technology

[0003] For water-rich strata with large permeability coefficient, the traditional synchronous grouting material will be diluted by groundwater after injection during shield construction, and the expected synchronous grouting effect cannot be achieved, especially in the case of high water pressure. Synchronous grouting The slurry material is more easily diluted, which leads to the destruction of the material structure. The grouting material cannot be condensed quickly, but instead increases the proportion of groundwater, which further intensifies the floating of the segment, especially in the case of a sudden change in the formation. Due to the equipment conditions of the slurry, the adjustment of equipment and pipelines on site is not only labor-intensive and time-consuming, but also cannot respond to the problem of segment floating in a timely and effective manner, resulting in unstable posture of the shield machine and a great safety risk

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