Foaming agent for shield

Abstract

The invention discloses a foaming agent for a shield. The foaming agent contains the components in percentage by weight: 1.0-10.0% of alpha-olefin sulfonate (AOS), 1.0-8.0% of sodium fatty alcohol -polyoxyethyleneether sulfate (AES), 1.0-6.0% of ammonium lauryl sulfate (K12 ammonium), 1.0-6.0% of cocoanut fatty acid diethanolamide (6501), 1.0-5.0% of dodecyl dimethyl betaine (BS-12), 0.005-0.1% of fluorocarbon surfactant (FS), 0.2-5.0% of sodium nitrilo triacetate (A92R), 0.2-5.0% of ethylene diamine tetraacetic acid disodium salt (EDTA) and the balance of water. The foaming agent for the shield provided by the invention realizes high multiple foaming rate, long foam stabilizing time, nontoxicity and innocuity and is an environment friendly biodegradable product which does not contain phosphorus.

Description

technical field [0001] The invention relates to a foaming agent, in particular to a foaming agent for earth pressure balance shield tunnel construction in subway tunnels. Background technique [0002] China's first subway was completed and opened to traffic in October 1968. By the end of the 1970s, my country's subway rail transit was only about 50 kilometers away from Beijing. However, so far, more than 10 cities including Beijing, Shanghai, and Guangzhou have successively built subway rail transit with different mileages. According to current statistics from relevant departments, nearly 50 urban rail transit lines are under construction across the country. In the next 5 to 10 years, The total length of urban rail transit lines across the country will exceed 2,000 kilometers. For example: Guangzhou City will complete 236 kilometers of subway rail transit mileage by 2015. [0003] In the early earth pressure balance shield construction of subway tunnels, the soil modifiers...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the defects of existing soil modifiers in the construction of earth pressure balance shield tunnels in subway tunnels, provide a brand-new foaming agent for shield tunnels, and realize the "slag discharge" in balanced shield tunnel construction. "Plastic flow state" to achieve: ① Improve the plastic flow of the excavated soil and reduce the torque of the cutterhead and earthmover; ② Prevent the excavated soil from adhering to the cutterhead panel and the inner wall of the pressure chamber; ③ Improve the water-tightness and prevent the excavation surface Subsidence; ④ Inhibit "cake formation", stabilize soil pressure, and increase tunneling speed; ⑤The product formula components are made of biodegradable raw materials, which are non-toxic and harmless. The discharged soil residue can be used as backfill, which can be achieved without special treatment Environmental requirements

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