A construction method of a shield tunnel

Abstract

A construction method for a shield tunnel, comprising: constructing uplift piles at intervals; constructing a ground reinforcement layer on the upper surface of the shield tunnel to be excavated; pouring a cushion on the ground reinforcement layer, and constructing a horizontal setting on the pouring cushion The caps of the uplift piles are anchored into the caps, and the ground reinforcement layer connects the caps, the uplift piles and the shield tunnel to be excavated. The caps are horizontal long beams, and two adjacent The distance D between platforms is 20-40m, and the method to determine the distance D is: calculate the remaining buoyancy force in the longitudinal direction of the shield tunnel; establish the continuous beam model of the longitudinal equivalent stiffness of the shield tunnel; The opening of shield tunnel segment lining shall not exceed 8mm, the dislocation between rings shall not exceed 15mm, the shear and tensile strength of bolts shall not exceed the design value, and the lining structure shall meet the strength and deformation requirements; shield tunnel excavation shall pass caps and uplift piles Assembling tunnel segments; constructing internal structures during excavation of shield tunnels or after penetration.

Description

technical field [0001] The invention relates to the field of shield tunnels, in particular to a construction method of shield tunnels. Background technique [0002] The anti-floating design of the shield tunnel is an important design part of the shield tunnel, which directly affects the line design and the determination of the construction scale of the tunnel. safety factor requirements. Specifically, the anti-floating design of the shield tunnel needs to meet the anti-floating stability requirements, and the formula is as follows: [0003] [0004] In the formula: G k - Anti-buoyancy of the tunnel, which is composed of the anti-buoyancy provided by the tunnel's own weight, ballast or other measures; [0005] f w - buoyancy value of the tunnel; [0006] K w ——Safety factor of anti-floating stability, check and calculate according to the most unfavorable situation, take 1.05 when the side friction resistance of the formation is not included; when the side friction re...

AI Technical Summary

Problems solved by technology

[0012] (1) The ground is heavily loaded and ballasted, and this anti-floating measure is generally difficult to achieve due to ground conditions during long-term operation;

[0013] (2) Use the useless space in the shield tunnel to fill concrete or other counterweight materials to increase the self-weight of the tunnel, but because the internal space of the shield tunnel is limited, the increased counterweight in the tunnel may not be able to completely overcome the buoyancy In some cases, it still cannot meet the safety requirements for anti-floating stability;

[0014] (3) Add a portal frame structure above the entire shield tunnel to increase the tunnel weight. The anti-floating measures require a large amount of work and high cost;

[0015] (4) Holes are opened in the internal structure of the shield tunnel, small uplift piles or anti-floating anchors are installed, and waterproof devices are installed. The anti-floating measures can increase the anti-buoyancy force less, and cannot fully meet the safety requirements for anti-floating stability

[0016] Therefore, several existing anti-floating measures have their own problems in actual construction, and cannot meet the actual construction needs.

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