Residue soil improver for waterless gravel backfilled stratum shield driving construction

Abstract

The invention discloses a residue soil improver for waterless gravel backfilled stratum shield driving construction. The improver is prepared from 0-6000 parts of sodium bentonite solution, 0-10 parts of clay dispersing agent, 0-10 parts of carboxymethyl cellulose and 20-130 parts of foaming agent. The soil regulated by the foaming agent has favorable flowability, plasticity and water permeation resistance, and the foaming agent has long duration on the soil improvement effect. The clay dispersing agent lowers the risks of blockage, delivery problem and the like, increases the driving speed of the shield machine, converts the high viscosity of the soil body into flowability and plasticity, and performs the function of improving the soil body. The carboxymethyl cellulose performs the gelation function, and prevents the residue soil from separation. Under the synergistic actions of the components, the improver increases the workability and flowability of the residue soil, so that the residue soil is in the plastic state, thereby stabilizing the pressure of the soil cabin and achieving the goals of controlling the slump of the tunnel face and the sinking of the ground surface and lubricating the tools.

Description

technical field [0001] The invention relates to the technical field of building construction, in particular to a dreg improvement agent used for shield tunneling construction of anhydrous gravel backfill strata. Background technique [0002] The stratum in Urumqi, Xinjiang is mostly anhydrous dense sand and pebbles. Due to economic development, especially the need for sand and soil in construction projects, a large number of sand filtering operations existed in the early stage, resulting in the existence of a large number of gravel backfill strata within the construction scope of the subway project. The gravel backfill formation has poor plasticity, the pressure of the soil chamber is unstable, and the set earth pressure cannot be smoothly transmitted to the operation face, which is easy to over-excavate. In addition, the self-stability of the ground is poor, and the surrounding area of ​​the operation face is easy to collapse, making it difficult for the surface to settle. ...

AI Technical Summary

Problems solved by technology

The gravel backfill formation has poor plasticity, the pressure of the soil chamber is unstable, and the set earth pressure cannot be smoothly transmitted to the operation face, which is easy to over-excavate. In addition, the self-stability of the ground is poor, and the surrounding area of ​​the operation face is easy to collapse, making it difficult for the surface to settle. Control; the high friction of the backfilling stratum is likely to cause high normal wear and damage of the cutter head and the cutter, which seriously affects the construction speed and efficiency. In addition, the replacement of the cutter during the excavation process also brings additional risks

At present, for the construction and excavation of shield tunneling in anhydrous gravel backfill formation, there is no corresponding mix ratio in terms of slag improvement, and the formation wears very seriously on the cutter and cutterhead, and it is difficult to guarantee the stability of the tunnel face. If the wear is too large, it is impossible to cut the soil on the face of the tunnel, resulting in the phenomenon of stopping the machine and changing the tool.