A special dreg improvement agent for shield tunneling in sand and pebble strata

Abstract

The invention discloses a muck improver special for a sandy gravel stratum shield. The muck improver is prepared from the following raw materials in percent by mass: 0.2-1.0% of a tackifying antiwear additive, 4.0-10.0% of an anionic surfactant, 1.0-4.0% of a nonionic surfactant A, 1.0-4.0% of a nonionic surfactant B and the balance of water with a total mass percent of 100%, wherein the tackifying antiwear additive is one or a mixture of anionic polyacrylamide, sodium carboxymethylcellulose and hydroxyethyl cellulose. The muck improver special for the sandy gravel stratum shield remarkably increases muck cohesive force, decreases osmotic coefficient and internal friction angle of muck, reduces abrasion of muck to equipment, improves flow plasticity of muck and reduces energy consumption.

Description

technical field [0001] The invention belongs to the technical field of shield tunnel construction, and in particular relates to a dreg improvement agent specially used for shield tunneling in sand and pebble formations. Background technique [0002] At present, the type of shield tunneling used in my country is mainly earth pressure balance shield tunneling, which is suitable for a wide range of geological conditions. The key to the success of earth pressure balance shield construction lies in effective muck improvement. The improvement of dregs is to inject the improver into the surface of the cutter head, the soil bin or the screw conveyor through the special device on the shield machine, and use the rotation of the cutter head, the stirring of the soil bin stirring device or the rotation of the screw conveyor to make the modifier and the muck The main purpose of mixing is to make the muck cut by the shield machine have good flow plasticity, suitable consistency, low wate...

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Problems solved by technology

[0003] The sandy pebble formation is a typical mechanically unstable formation, which has the characteristics of small cohesion, large internal friction angle, large permeability coefficient, poor fluidity, and poor stability. The sand and pebbles cut by the cutter head into the soil bin have poor plasticity, and are prone to technical problems such as difficulty in excavation (occlusion), gushing, abnormal excavation parameters and difficult excavation, difficult establishment of soil pressure, and serious equipment wear

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