Protective structure for existing tunnel under working condition of close-range crossing by shield and construction method of protective structure

Abstract

The invention discloses a protective structure for an existing tunnel under the working condition of close-range crossing by a shield and a construction method of the protective structure, and belongsto the technical field of subway tunnel structure reinforcement and protection. The protective structure is arranged at a grouting hole of a segment; a protective cover is fixed to the inner surfaceof the segment, a pumping tube communicates with the protective cover and a vacuum pump; an opened metal sleeve is arranged in the protective cover, the top end of the opened metal sleeve is in contact with the protective cover, the bottom of the opened metal sleeve is connected with one end of a metal pipe section, the metal pipe section is embedded in the grouting hole, and a pressure relief opening is formed in the position, near the grouting hole, of the opened metal sleeve in the circumferential direction; a pressure spring is arranged inside the opened metal sleeve, the top end of the pressure spring is fixed to the protective cover, and the bottom end of the pressure spring is connected with a pressure relief piston; the pressure relief piston is arranged in the metal pipe section;on the outside of the tunnel, one end of a glass fiber reinforced plastic hollow anchor rod is connected with the metal pipe section in the grouting hole, and reserved small holes are formed in the surface of the glass fiber reinforced plastic hollow anchor rod in the circumferential direction. According to the protective structure for the existing tunnel under the working condition of close-rangecrossing by the shield and the construction method of the protective structure, the dual functions of water pressure draining and earth pressure draining are realized, and the glass fiber reinforcedplastic hollow anchor rod is used for connection and reinforcement.

Description

technical field [0001] The invention belongs to the technical field of reinforcement and protection of subway tunnel structures, and in particular relates to a protective structure and a construction method for an existing tunnel under the short-distance crossing condition of a shield machine, which is suitable for the short-distance crossing of the existing tunnel under the short-distance working condition of the shield machine It is especially suitable for the prevention and control of deformation of the existing tunnel ring under the additional load of uneven grouting and soil extrusion. Background technique [0002] The urban subway is convenient to travel and can effectively alleviate urban traffic congestion. Many cities in China have started their own subway construction. With the development of the subway network, there are more and more working conditions in which shield tunnels pass through existing tunnels at close distances in the shallow urban space. [0003] T...

AI Technical Summary

Problems solved by technology

Among them, the diffusion range of circumferential grouting is difficult to control, and it is often necessary to inject a large amount of grout to reinforce a certain area, causing additional pollution to the environment; and setting anchor rods under the condition of multi-line overlapping may affect the subsequent excavation of new shield tunnels ;Setting the pressure relief hole is often only to release the water pressure to relieve the upward deformation of the shield tunnel, and the pressure relief device itself is simple and can be further developed in terms of functionality

[0004] To sum up, the existing technologies generally have problems such as poor protection effect, impact on the subsequent excavation of adjacent shield tunnels, and insufficient functions, etc., which urgently need to be solved by improving the technology

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