Low gas shield tunnel shield tail seal structure
Technical Field
The utility model relates to a subway tunnel structure, concretely relates to low gas shield tunnel shield tail seal structure.
Background
In the fast development stage of the shield tunnel in China, large-scale shield tunnel construction faces a lot of problems, wherein when a shield machine passes through a sandy soil or pebble stratum rich in water for a long distance, a shield tail brush is easy to wear and even damaged to cause leakage, so that the shield tail brush losing the sealing effect needs to be replaced.
The shield tail annular sealing brush of the shield tunnel is one of important accessories of the shield machine, is generally formed by fluffing a steel wire after bending, and inevitably wears between the shield tail annular sealing brush and the shield tunnel in the shield tunnel construction process, so that when the shield tail annular sealing brush is worn to a certain degree, water leakage or even silt leakage of the shield tail is caused. Particularly, in the construction process of the interval shield tunnel with larger length, the shield is positioned in the stratum to replace the shield tail brush. The problem of leakage prevention of the shield tail is solved in the process of disassembling the old shield tail annular sealing brush and assembling the new shield tail annular sealing brush. In the prior art, in order to solve the problem of shield tail leakage in the replacement process of the shield tail annular sealing brush, the stratum around the shield tail is generally frozen or a waterproof material is adopted to perform grouting seepage prevention in the stratum at the tail part of the shield.
In the gas tunnel, the gas that the shield tail permeates is the important source of the gas in the shield tunnel, and when emergency takes place, the shield constructs the machine and need shutting, all gas sources need be sealed this moment, among the prior art, lack and carry out the technique that the shield tail was sealed under the gas tunnel emergency.
SUMMERY OF THE UTILITY MODEL
The utility model aims to solve the technical problem that a low gas shield constructs tunnel shield tail seal structure is provided to the emergent emergency of gas improves the seal of shield tail in effectively handling the work progress, prevents that gas from getting into the shield through the shield tail in the shield tunnel construction, ensures the security of shield tunnel construction.
The utility model provides a technical scheme that this technical problem adopted as follows:
the utility model discloses a low gas shield tunnel shield tail seal structure, include the multichannel ring seal brush that vertical interval set up on the shield tail inner wall, the front end and the tunnel lining section of jurisdiction outer wall contact of each ring seal brush, two adjacent ring seal brushes form ring seal chamber, characterized by between shield tail inner wall and tunnel lining section of jurisdiction outer wall: and annular air bags are fixedly arranged on the inner wall of the shield tail in each annular sealing cavity, and the inflated and expanded annular air bags form sealing between the inner wall of the shield tail and the outer wall of the tunnel lining segment.
In order to further improve the sealing performance of the shield tail, an annular oil-immersed sealing brush is fixedly arranged at the tail end of the shield tail on the inner wall of the shield tail, sealing grease is attached to the annular oil-immersed sealing brush, and the front end of the annular oil-immersed sealing brush is closely attached to the outer wall of a tunnel lining segment to form sealing.
The utility model has the advantages that the annular air bag is arranged in the annular sealing cavity between the two adjacent annular sealing brushes at the shield tail, the annular air bag is inflated and expanded and fills the annular sealing cavity, and sealing is formed between the inner wall of the shield tail and the outer wall of the tunnel lining segment, so that gas can not enter the shield machine through the shield tail, and the emergency situation of gas burst in the construction process can be effectively coped with; an annular oil immersion sealing brush is additionally arranged at the tail end of the shield tail, so that the shield tail tightness is further improved, and the safety of shield tunnel construction is ensured; simple structure, strong implementability and the like, and effectively overcomes the defects of the prior shield tail closed structure.
Drawings
The specification includes the following two figures:
fig. 1 is a schematic view of a shield tail sealing structure of a low gas shield tunnel of the present invention;
fig. 2 is the expansion schematic diagram of the annular airbag in the shield tail sealing structure of the low gas shield tunnel of the utility model.
The figures show the main component names and the corresponding labels: the shield tail 10, annular sealing brush 11, annular immersion oil sealing brush 12, annular gasbag 13, tunnel lining section of jurisdiction 20.
Detailed Description
The present invention will be further explained with reference to the drawings and examples.
Referring to fig. 1 and 2, the utility model discloses a low gas shield tunnel shield tail seal structure, include the multichannel annular seal brush 11 that vertical interval set up on shield tail 10 inner walls, the front end and the 20 outer wall contacts of tunnel lining section of jurisdiction of each annular seal brush 11, and two adjacent annular seal brushes 11 form the annular seal chamber between shield tail 10 inner walls and 20 outer walls of tunnel lining section of jurisdiction. And annular airbags 13 are fixedly arranged on the inner wall of the shield tail 10 in each annular sealing cavity, and the inflated and expanded annular airbags 13 form sealing between the inner wall of the shield tail 10 and the outer wall of the tunnel lining segment 20. The annular air cells 13 are normally in a closed state and do not occupy the space between the annular sealing brushes 11. When gas emergency occurs in the construction process, the annular air bag 13 is inflated and expanded and fills the annular sealing cavity, so that gas cannot enter the shield tunneling machine through the shield tail.
Referring to fig. 1 and 2, in order to further improve the sealing performance of the shield tail, an annular oil-immersed sealing brush 12 is fixedly arranged at the tail end of the shield tail 10 on the inner wall of the shield tail, sealing grease is attached to the annular oil-immersed sealing brush 12, and the front end of the annular oil-immersed sealing brush is closely attached to the outer wall of a tunnel lining segment 20 to form sealing. The annular oil-impregnated sealing brush 12 is immersed in a heated and melted sealing grease before installation, so that the sealing grease can fully fill the gaps between the brush filaments. In the tunneling process, the annular oil-immersed sealing brush 12 and the sealing grease attached to the annular oil-immersed sealing brush can effectively prevent gas from entering the shield tunneling machine through the shield tail.
The above is only used for illustration the utility model discloses some principles and functions of low gas shield tunnel shield tail seal structure are not intended to be general the utility model discloses the limitation show with concrete structure and application scope in, all corresponding amendments and equivalents that probably are utilized all belong to the utility model discloses the patent range who applies for.