Shield tunnel anti-floating system based on pre-stressed anchor cable and construction method of shield tunnel anti-floating system

Abstract

The invention relates to a shield tunnel anti-floating system based on a pre-stressed anchor cable and a construction method of the shield tunnel anti-floating system. Annular longitudinal joints of shield tunnel segments cause the overall stiffness of a tunnel to be relatively weak, and development or structure construction of land masses close to the constructed tunnel maybe cause tunnel longitudinal uneven upward floating (upheaval) deformation. The shield tunnel anti-floating system comprises a shield tunnel formed through segmental lining splicing, a damping ballast bed is arranged at the arch bottom of the shield tunnel, and the pre-stressed anchor cable is arranged in a segment lining reserved injected hole in a striking mode; and the pre-stressed anchor cable is arranged within the range of 60 degrees on the left side and the right side of the arch bottom and comprises a plurality of steel strands which are distributed in a circumferential mode, and grouting pipes are arranged in the centers of circles. According to the shield tunnel anti-floating system, through the pre-stressed anchor cable exerted on a shield tunnel segment lining, the tunnel is fixed to a designated position, the disadvantageous influence of the segment annular longitudinal joints is counteracted to a certain extent, the fixing effect can be correspondingly adjusted through the length of the anchor cable and the pre-stress value, and the capacity of the tunnel for resisting to changing of the surrounding environment is improved.

Description

technical field [0001] The invention relates to the technical field of tunnel engineering, in particular to a shield tunnel anti-floating system based on prestressed anchor cables and a construction method thereof. Background technique [0002] At present, the infrastructure construction of major cities in China is developing in a blowout style, such as urban rail transit projects. The construction level and speed of urban rail transit reflect the development speed of cities to a certain extent. While urban rail transit provides convenience for citizens to travel and accelerates the pace of urban development, it also bears threats from various aspects, among which structural safety, long-term durability and stability are the most prominent. [0003] The construction of urban rail transit has significantly accelerated the development of plots along the line and regional economic development, but at the same time, it needs to face the threats brought about by changes in the su...

AI Technical Summary

Problems solved by technology

[0004] During the operation of the subway, there are often situations such as leakage of segment joints, local cracks or brokenness that affect normal operation, and since urban rail transit tunnels generally use shield machines with a diameter of about 6m to excavate, the distance between the building boundary and the inner diameter of the tunnel The reserved space is generally only about 100-200mm. Considering construction errors, equipment installation errors and long-term uneven settlement of the stratum, there is no room to consider the adverse effects caused by changes in the surrounding environment in the later period.

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