Foaming agent for improving shield muck in cohesive soil layer and preparation method and use method of foaming agent

Abstract

The invention discloses a foaming agent for improving shield muck in a cohesive soil layer. The foaming agent comprises a foaming agent base solution, powder abelmoschus manihot gum as an additive and water; the volume part ratio of the foaming agent base solution to the water is (3-15): 100, and the mass part ratio of the additive to the water is (0.025-0.1): 100; the foaming agent base solution comprises a solid material alkyl sucrose glycoside serving as a main foaming agent and a liquid material fatty alcohol-polyoxyethylene ether sodium sulfate serving as an auxiliary foaming agent, and the volume fraction ratio of the alkyl sucrose glycoside to the fatty alcohol-polyoxyethylene ether sodium sulfate is 2: 1. Meanwhile, the invention further discloses a preparation method of the foaming agent for improving the shield muck in the cohesive soil layer and a use method of the foaming agent for improving the shield muck in the cohesive soil layer. The foaming agent is suitable for earth pressure balance shield muck improvement construction of the cohesive soil layer, the foaming ratio of the foaming agent is higher than 20 times, the half-life period is longer than 1200 s, the half-life period is almost zero within 5 min, generated foam is high in stability, high in gas-liquid level strength and high in foam density, and the foaming agent can enter soil gaps easily to improve the flow plasticity of the soil.

Description

technical field [0001] The invention relates to the technical field of engineering construction materials, in particular to a shield dreg foaming agent, a preparation method and a use method, and is especially suitable for cohesive soil layers. Background technique [0002] At present, the shield subway has become an important part of urban traffic construction. The risk of shield tunneling when passing through the cohesive soil layer mainly comes from the "blocking" problem and the "mud cake" problem caused by the characteristics of the soil layer. The fundamental reason is that Due to the lack of flow plasticity of the cohesive soil, the shield machine cannot be unearthed normally, and the increase in the internal pressure of the soil chamber makes the soil arch, causing the advancement of the shield to continue to worsen this phenomenon. The cohesive soil lacks fluidity, and the soil consolidates to form a hard block under the propulsion pressure of the shield. Once such ...

AI Technical Summary

Problems solved by technology

[0004] The present invention aims to provide a cost-effective, environmentally friendly, stable and reliable general-purpose foaming agent suitable for cohesive soil layers, so as to solve the potential risks caused by the lack of flow plasticity of cohesive soil during shield tunneling