Starting end tunnel portal sealing device and method when shield tunneling machine starts to downwards transverse existing shield tunnel immediately

Abstract

The invention provides a starting end tunnel portal sealing device and method when a shield tunneling machine starts to downwards transverse an existing shield tunnel immediately. The sealing device comprises an extension steel ring and an extension steel ring supporting structure. The steel ring supporting structure comprises a base support arranged on a steel ring base, a horse stool support arranged in a groove in the bottom of the extension steel ring, and steel ring supports arranged on two sides of the extension steel ring; the extension steel ring is connected with an embedded steel ring of a shield tunnel portal and is fixedly supported with a main body side wall of the shield tunnel portal and a structural beam through a steel ring supporting structure; and two steel wire brushesare arranged on the inner side of the extension steel ring, a cord fabric rubber plate is arranged at the tail end of the extension steel ring and forms three cavities in the extension steel ring, anda plurality of ball valves are arranged on the outer side of the steel ring and correspond to the cavities. The tunnel portal can be blocked in advance, it is guaranteed that a soil bin can reduce pressure in advance before a shield cutter head enters an existing line, falling of soil above the cutter head is reduced, stratum settlement is prevented, and it is guaranteed that the shield machine safely and stably passes through the existing line.

Description

technical field [0001] The invention belongs to the field of shield tunneling, and specifically relates to a method for establishing the pressure of the shield soil bin in advance when the shield machine starts to pass through the existing shield tunnel. A sealing structure is set in the ring to establish a complete and effective earth chamber pressure before the start of the shield machine, so as to ensure that the shield machine can pass through the existing shield tunnel safely, quickly and smoothly at the time of start, and prevent the shield machine from The ground subsides when passing through the existing shield tunnel. Background technique [0002] With the rapid development of my country's economy, people's pace of life is gradually accelerating, and more and more people begin to flock to the city, which puts pressure on urban traffic. An important means of transportation for traffic pressure. For the construction of subway tunnels, we are now increasingly using sh...

AI Technical Summary

Problems solved by technology

During the excavation process of the shield machine, the disturbance of the cutter head will affect the soil around the face. If the pressure of the soil bin is insufficient, it will often cause the face of the face to collapse, forming a local cavity, and finally leading to the subsidence of the bottom layer.

At present, most of the conventional methods for establishing accurate soil bunker pressure are gradually established during the excavation process. However, in the process of going down the existing line at the beginning, the soil bunker pressure has not yet been fully established because the shield machine has just started excavating. , at this time, the face of the tunnel is easy to collapse, causing ground subsidence and affecting the operation of existing lines

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