Acid-resistant shield foaming agent

Abstract

The invention discloses an earth pressure balance type shield foaming agent. The foaming agent comprises the following components by weight percent: 2.5-10.0% of fatty alcohol polyoxyethylene ether (AEO-9), 2.0-8.0% of alkyl glucoside (APG), 2-6.5% of dodecyl betaine, 1.0-3.0% of polyethylene glycol (PEG4000), 2-4.5% of ammonium sulfate and 32.0-90.5% of water. Through the earth pressure balance type shield foaming agent disclosed by the invention, high-rate foaming can be realized even in an acid condition, and the generated foam is fine while the stabilization time is long; and the product can perfectly meet the requirements of modified acid residue soil in a tunneling process of an earth pressure balance shield machine.

Description

technical field [0001] The invention belongs to the technical field of materials, and relates to a foaming agent for earth pressure balance type shield construction under acidic conditions. [0002] technical background [0003] At present, China's subway construction is developing rapidly. Earth pressure balance shield technology is often used in subway tunnel construction. The key to this technology is to keep the soil in a plastic flow state. During construction, a certain amount of foam is usually injected into the shield machine. Improve the soil. Because soil is a complex system, there are various chemical and biochemical reactions in it, which makes the soil show different acidity and alkalinity. Most of the soil pH in my country is in the range of 4.5 to 8.5, and the pH value increases from south to north. The soil south of the Yangtze River (33°N latitude) is mostly acidic and strongly acidic, such as the red soil and yellow soil widely distributed in South China an...

AI Technical Summary

Problems solved by technology

Most of the soil pH in my country is in the range of 4.5 to 8.5, and the pH value increases from south to north. The soil south of the Yangtze River (33°N latitude) is mostly acidic and strongly acidic, such as the red soil and yellow soil widely distributed in South China and Southwest China. Most of them are between 4.5 and 5.5; the red soil in East and Central China has a pH value between 5.5 and 6.5; and acidic soil will make the foam unstable during construction, which will cause the soil to lose its plastic flow state, resulting in shield machine There are technical problems such as "blocking", "squirting" of sediment, and "cake formation" of soil