Synchronous shielding grouting material composite admixture

Abstract

The invention discloses a synchronous shielding grouting material composite admixture which comprises the following raw materials in percentage by mass: 10-20% of a coagulant, 10-20% of a retarder, 40-50% of an efficient water reducer, 10-20% of a tackifier, 1-5% of a defoaming agent and 1-5% of a plasticity expander. The admixture has the effects that in a high-pressure water-enriched stratum environment, on premise that equipment and pipelines are not changed, the curing time can be adjusted, the working performance loss is small within the curing time, and good water dispersibility resistance, efficient filling and rapid curing can be achieved.

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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