High-performance inert slurry for grouting of back of shield tunnel segment

Abstract

The invention mainly provides a high-performance inert slurry for grouting of the back of a shield tunnel segment, belonging to the technical field of shield tunnel construction. The high-performance inert slurry comprises the following components in proportion by weight: 90kg / m<3> of slaked lime, 410kg / m<3> of fly ash, 780kg / m<3> of river sand, 465kg / m<3> of water, 105kg / m<3> of sodium bentonite and 3kg / m<3> of FD-3 high-concentration and high-efficiency water reducing agent, wherein the mass ratio of the fly ash to the slaked lime is 4.56:1, and grade II fly ash is adopted; the mass ratio of the total consumption of the slaked lime and the fly ash to the river sand is 1.56; and the addition of the sodium bentonite accounts for 22.8% of the water consumption. The invention overcomes the defects of long time of coagulation, low strength of induration and large volume shrinkage of the current inert slurry, realizes good matching of filling property, flowing property and bonding strength, has the advantages of convenient construction, easy control of quality of the slurry, simple mixing of the slurry and lower unit price of the slurry, can obviously reduce the engineering cost, and has excellent economic benefit and social benefit.

Description

technical field [0001] The invention belongs to the technical field of shield tunnel construction, and mainly provides a high-performance inert slurry for back grouting of shield tunnel segments. Background technique [0002] The shield method is a construction method that uses a shield machine to excavate a tunnel below the ground. During shield construction, the shield machine excavates the soil by rotating the cutter head at the front of the shield, and the segment installation machine at the rear assembles the segments under the protection of the shield shell to form a tunnel support structure, and the shield shell comes out of the segments Finally, the back grouting system of the shield tail injects grout into the gap between the segment and the formation to fill the gap between the segment and the formation, reduce the disturbance of the shield construction to the surrounding soil, and prevent the tunnel and the ground from being disturbed. Sinking, the purpose of pro...

AI Technical Summary

Problems solved by technology

However, through retrieval of prior art and patent literature, it is found that the existing inert slurries at home and abroad all have long coagulation time (more than 10h), low strength of consolidated body (28d compressive strength<1.0MPa), volume shrinkage (consolidation The shrinkage rate is greater than 5%) and other shortcomings

Therefore, the surface settlement cannot be well controlled, making the segment structure unstable