Waste soil improving method of soil pressure balance shield of high water pressure and high permeability sandy stratum

Abstract

A waste soil improving method of soil pressure balance shield of a high water pressure and high permeability sandy stratum comprises the steps that A, 0.8-1.2 parts by weight of sodium bentonite, 0.04-0.06 part by weight of carboxymethyl cellulose and 10 parts by weight of water are mixed, stirred continuously for 10-15 min and then placed in a container to stand for 20-24 h, and improved slurry is obtained; and B, before driving, the water containing state of rock soil of an excavation face is measured, in the soil pressure balance shield driving process, the improved slurry is injected into a soil bin of a shield machine, if the measured water containing state of the rock soil is a supersaturated state, the ratio of the injection volume of the improved slurry to the waste soil entering volume of the soil bin is 1:2-3.4, and otherwise, the ratio of the injection volume of the improved slurry to the waste soil entering volume is 1:3.5-4.5. By improving waste soil through the waste soil improving method, gushing can be better avoided and relieved during soil pressure balance shield construction, and the influence on the engineering progress is less; and the cost of subway construction is reduced.

Description

technical field [0001] The invention relates to a dreg improvement method for earth pressure balance shield construction in sandy strata. Background technique [0002] The continuous growth of my country's urban economy and population has caused a series of urban problems such as traffic congestion and urban pollution. The subway has become the most important means of public transportation due to its advantages of high efficiency, greenness and environmental protection. Due to the advantages of safe construction, fast excavation speed, adaptability to complex strata and small surface settlement, the shield method has become the most important construction method for urban subways today. [0003] Shield machines are divided into two categories: slurry balance shield machines and earth pressure balance shield machines. The mud-water balance shield machine is suitable for the construction of high-permeability strata, but it is expensive and the construction cost is high. The ...

AI Technical Summary

Problems solved by technology

In actual engineering, it often occurs that the double gates are stuck by stones or the double gates are rusted and fail, which makes the double gates unable to close in time, which brings huge risks to the shield construction

Therefore, the setting of double-helix excavators and double gates is usually only used as emergency measures when gushing occurs, which is difficult to ensure the safe and smooth implementation of construction, and sometimes brings great inconvenience to construction and seriously affects the progress of the project.