Water-rich round-gravel stratum shield muck improvement method and muck improvement agent

Abstract

The invention discloses a muck improvement agent which comprises liquid A and liquid B. The liquid A comprises, by weight, 0.25-0.33 parts of sodium bentonite, 0.01-0.015 part of carboxymethylcellulose and 1 part of water. The liquid B comprises, by weight, 0.001-0.003 part of polyacrylamide and 1 part of water. The invention further discloses a method for improving water-rich round-gravel stratumshield muck by the muck improvement agent. According to the muck improvement agent, the liquid A with the volume injection ratio of 30%, the liquid B with the volume injection ratio of 7.5% and soilsamples from an on-site water-rich round-gravel stratum are stirred and mixed, the collapsing degree can be controlled within 20cm, a permeability coefficient K of improvement soil reaches 1*10<-7>m / sunder water pressure of 2.5bar (25m water head), continuous time reaches 4 hours or more, the permeability coefficient is smaller than 1*10<-5>m / s serving as a flowing critical value, and improvementeffects are good.

Description

technical field [0001] The invention belongs to the technical field of dreg improvement in shield tunneling, and in particular relates to a method for improving dregs in a water-rich round boulder stratum and a dregs modifier. Background technique [0002] Shield machine is a commonly used machine in subway construction. Its basic principle is to maintain its stability by applying a certain pressure to the excavation surface. According to the different ways of applying pressure, it can be divided into mud-water type shield machine and earth pressure balance type. shield etc. The earth pressure balance shield is suitable for all kinds of strata except the high water pressure and strong permeable stratum, with fast excavation speed, little impact on the environment and relatively low cost, which has become the first choice for most urban subway construction. [0003] The earth pressure balance shield machine uses the muck in the soil bin as the medium to stabilize the excavat...

AI Technical Summary

Problems solved by technology

In terms of muck improvement technology, the existing patents are mainly aimed at controlling the safety risks of shield tunneling in water-rich sand and sandy pebble formations. There are few improvement technologies and solutions for water-rich round gravel formations, especially for shield tunneling. The left and right lines overlap and pass through the existing line, and at the same time, higher requirements are placed on the deformation and stability of the ground, and there is a lack of corresponding muck improvement technology