JPH08254096A - Tail seal replacing method for shield machine - Google Patents

Abstract

PURPOSE: To replace tail seals safely without any restriction on the position for tail seal replacement. CONSTITUTION: Prior to replacement of tail seals 7, 7..., seal replacing segments 10, 10... equipped with opening 10a leading from the inside to outside are installed over the whole peripheral circumference. After this is exposed to the surrounding ground G2 situated behind with progress of a shield machine 1, a liquid is infected from infection pipes 12, 12... installed on the segments 10, 10... so that, the surrounding ground G2 is improved in a specified range. Then the tail seals 7, 7... are replaced with new ones.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield excavator tail seal exchanging method suitable for use in constructing a tunnel over a long distance such as a subway or sewage.

[0002]

2. Description of the Related Art As is well known, when constructing a tunnel by using a shield construction method, a segment is assembled into a predetermined shape in a skin plate forming an outer shell of the shield excavator while excavating the ground with the shield excavator. By
A tunnel is built behind the shield excavator.

In such a shield excavator, in order to prevent ground water and earth and sand from flowing into the shield excavator from the gap between the outer peripheral surface of the assembled segment and the inner peripheral surface of the skin plate, the rear end of the skin excavator is prevented. Part is equipped with a tail seal. This tail seal may be damaged especially when constructing a tunnel over a long distance, for example, for subways or sewage, and if the tail seal is damaged, it needs to be replaced.

Conventionally, in order to replace the tail seal, the ground is improved by, for example, injecting a chemical solution into the surrounding ground so that groundwater and earth and sand do not flow into the shield excavator from the gap during the replacement work to ensure safety. After that, I was replacing the tail seal from inside the shield excavator.

[0005]

However, there are the following problems in the conventional tail seal exchanging method for a shield excavator as described above. First of all, in order to improve the ground around the shield excavator in order to replace the tail seal, it is necessary to inject a chemical solution from the ground surface. Is a problem. This problem is the same in places where soil pressure and groundwater pressure from the surrounding ground are high. In order to perform sufficient ground improvement in such a place, the cost required for ground improvement will be great. For this reason, at present, the replacement work of the tail seal can be performed only in a place where the soil cover is shallow and the earth pressure and the groundwater pressure are low, which restricts the place of the tail seal replacement. There was a problem. In addition, when the tail seal needs to be replaced at the position where the shield excavator is stopped, there is a problem in work safety because the ground improvement under the shield excavator cannot be sufficiently performed. It was The present invention has been made in view of the above points, and provides a tail seal replacement method for a shield excavator that can safely replace the tail seal without being restricted by the replacement position of the tail seal. The purpose is to provide.

[0006]

The invention according to claim 1 is
While excavating the ground in front with a shield excavator, when the tunnel is built behind the segment by assembling the segments in the substantially cylindrical skin plate that forms the outer shell of the shield excavator, the assembled segment Prior to replacing the tail seal provided in the tail portion of the skin plate to close the gap between the outer peripheral surface of the skin plate and the inner peripheral surface of the skin plate, a tail seal replacement segment having an opening communicating the inside and the outside, After continuously assembling the previously assembled segment, the excavation is continued to advance the shield excavator to expose the tail seal replacement segment in the ground behind the tunnel, and then the tunnel is solidified by the ground solidification means. From the inside, solidify the surrounding ground through the opening of the tail seal replacement segment, and then It is characterized by replacing the tail seal in the shield excavating machine.

According to a second aspect of the present invention, in the tail seal exchanging method for a shield excavator according to the first aspect, the ground solidifying means is inserted into the opening of the tail seal exchanging segment, and a chemical liquid injection pipe is inserted, It is characterized in that the ground is improved by injecting the liquid medicine into the surrounding ground from the liquid medicine injection pipe.

According to a third aspect of the present invention, in the tail seal exchanging method for a shield excavator according to the first aspect, the ground solidifying means is inserted into a hole of the tail seal exchanging segment, and a freezing pipe is inserted into the freezing pipe. The feature is that the surrounding ground is frozen by a pipe.

[0009]

According to the first aspect of the present invention, prior to the replacement of the tail seal, a tail seal replacement segment having an opening communicating with the inside and outside is assembled, and the tail seal is replaced in the ground behind the shield machine by advancing the shield machine. After exposing the use segment, the surrounding solid is solidified from the inside of the tunnel through the opening of the tail seal replacement segment by the ground solidifying means, and then the tail seal is replaced.
In this way, by mounting the tail seal replacement segment and solidifying the surrounding ground,
It can solidify from within the tunnel rather than from the ground surface. At this time, by mounting the tail seal replacement segment over the entire circumference of the tunnel, the surrounding ground can be solidified over the entire circumference.

According to the second aspect of the present invention, the ground solidifying means is configured such that the chemical solution injection pipe is inserted into the opening of the tail seal replacement segment, and the chemical solution is injected into the surrounding ground from the chemical solution injection pipe. Thereby, the surrounding ground can be improved and solidified by the injected chemical solution.

According to the third aspect of the invention, a freezing pipe is inserted into the opening of the tail seal replacement segment, and the surrounding ground is frozen by the freezing pipe. As a result, the surrounding ground and groundwater can be solidified.

[0012]

The present invention will be described below with reference to the first and second embodiments shown in the drawings.

[First Embodiment] First, here, in the case where the tail seal is replaced by applying the tail seal replacement method of the shield excavator according to the present invention, a first case in which the surrounding ground is improved by chemical injection An example will be described.
FIG. 1 shows the tunnel T under construction. As shown in this figure, a shield excavator 1 for constructing a tunnel T has a cylindrical outer shape in cross section and has a ground G in front of the excavation direction.
A substantially disk-shaped excavating portion 2 for excavating 1 is provided, and a cylindrical skin plate 3 forming an outer shell thereof is provided on the rear side thereof.
It has a schematic configuration including. Inside this skin plate 3, a drive device 4 for driving the excavation portion 2 to rotate about its axis, a slip-out device 5 for discharging the excavated slit backward, and a segment of reinforced concrete structure that constitutes a tunnel T to be built. A segment assembly device (not shown) for assembling S into a predetermined shape, a hydraulic jack 6 for advancing the shield excavator 1 by obtaining a reaction force to the assembled segment S, and the like are provided.

On the inner peripheral surface of the tail portion 3a of the skin plate 3, ground water or earth and sand of the surrounding ground G2 is discharged from the gap between the outer peripheral surface of the assembled segments S, S, ... And the inner peripheral surface of the tail portion 3a. In order to prevent it from flowing in, a plurality of tail seals 7, 7, ... Are provided.

In the shield excavator 1 as described above, the excavation part 2 is rotated by the drive device 4 to excavate the front ground G1 as in the conventional case, and the segment assembly device (not shown) is provided in the skin plate 3. ), The segments S, S, ... Are assembled into a predetermined shape. Then, the segment S, which is assembled by extending the hydraulic jack 6,
A tunnel T is constructed on the rear side of the shield excavator 1 by advancing the shield excavator 1 in the direction of the arrow (a) in the figure by obtaining a reaction force at the front end of S, ....

Next, a method of replacing the tail seals 7, 7, ... Of the shield excavator 1 when they are damaged will be described. First, the tail seals 7, 7, ...
The position P for exchanging is determined. Then, the tunnel T is built, and before the exchange position P by a predetermined size, the segment S made of reinforced concrete is used instead of the segment S made of reinforced concrete to replace these with the skin plate. With the segment assembling device (not shown) in 3, the ordinary segments S, S,
Assemble the entire circumference of the tunnel T in succession to. Each tail seal replacement segment 10 is made of steel,
An opening 10a that communicates with the inside and outside is formed at a predetermined position on the peripheral surface.

Then, the tail seal replacement segment 1
After assembling 0, 10, ... For 2 rings in the length direction of the tunnel T, for example, the excavation of the ground G1 in the front by the shield excavator 1 is continued, and the normal segment S is assembled to extend and build the tunnel T. . After this, shield excavator 1
When the tail seal replacement segments 10, 10, ... Assembled earlier are exposed to the surrounding ground G2 behind the tail portion 3a of the skin plate 3 by the forward movement of the shield excavator 1, the excavation of the shield excavator 1 is temporarily stopped. (State shown in FIG. 1).

Subsequently, after the packer 11 is attached to the opening 10a of each tail seal replacement segment 10, the chemical solution injection pipes (ground solidifying means) 12, 12, ...
From inside of, through each packer 11, insert into the surrounding ground G2. At this time, the insertion angle and the insertion length of each chemical solution injection pipe 12 are set so that the surrounding ground G2 'within a predetermined range is improved.

A chemical injection pipe 1 is provided all around the tunnel T.
After the installation of 2, 12, ... Is completed, a chemical solution for ground improvement is supplied from a chemical solution injection device (not shown) to the chemical solution injection pipes 12, 12 ,.
And inject it into the surrounding ground G2. Then, by injecting a predetermined amount of the chemical liquid, the surrounding ground G2 'in a predetermined range is improved and solidified, and the tail seal 7,
Leakage from 7, ... will be prevented and groundwater will not flow. Needless to say, the injection amount of this chemical solution is set according to the soil quality, the amount of groundwater, etc. so that the surrounding ground G2 'within a predetermined range is surely improved.

In this way, the surrounding ground G2 'within the predetermined range
, The segment S ', which is assembled to the front side of the tail seal replacement segments 10, 10 ,.
The tail seal 7, which should be replaced by removing S '...
Expose 7, ... Then, these tail seals 7,
Remove 7 ... and replace it with a new tail seal 7, 7.

After the replacement work of the tail seals 7, 7, ... Is completed, the removed segments S ', S' ,. Along with this, the chemical liquid injection pipe 1 inserted in the tail seal replacement segments 10, 10 ,.
Remove 2, 12, ...

Then, in the same manner as usual, the tunnel T is constructed by assembling the segments S, S, ... While excavating the ground G1 in front of the excavation section 2 of the shield excavator 1. I will do it.

In the method of replacing the tail seals 7, 7, ... Of the shield excavator 1 described above, the tail seal replacement segment having the opening 10a for communicating the inside and outside is exchanged before the tail seals 7, 7 ,. ... are assembled over the entire circumference, and after this is exposed in the surrounding ground G2 behind by the advance of the shield excavator 1, the chemical liquid injection pipes 12, 12, attached to the tail seal replacement segments 10, 10 ,. By injecting a chemical solution from the ..., the surrounding ground G2 'in a predetermined range is improved and solidified, and then the tail seals 7, 7, ... are replaced. In this way, it is possible to improve the surrounding ground G2 'within a predetermined range from inside the tunnel T, not from the ground surface, so that the ground is sufficiently improved around the entire circumference of the tunnel T regardless of its depth, location, etc. can do. Therefore, the tail seals 7, 7, ... Are exchanged at any position of the tunnel T, such as at a large depth or in a place where earth pressure or groundwater pressure is high, without being restricted by the replacement position P of the tail seals 7, 7 ,. Work can be performed safely. Further, by improving the surrounding ground G2 'within a predetermined range from inside the tunnel T, not from the ground surface, it is possible to reduce the amount of chemical liquid used and suppress the ground improvement cost.

[Second Embodiment] Next, applying the tail seal exchanging method of the shield excavator according to the present invention, the ground improvement only by injecting the chemical liquid is not sufficient, the freezing method is required, and the groundwater flow is reduced. Yes When replacing the tail seal in the ground where the growth of frozen soil may be hindered,
A second embodiment in which the ground is solidified by freezing the surrounding ground together with the injection of the chemical liquid will be described. The surrounding ground G2 is not enough to improve the ground only by injecting chemicals,
In the case of the ground where the freezing method is required and there is a possibility that the growth of frozen soil may be hindered due to the groundwater flow, first, the tail seals 7, 7, ... Are replaced in the same manner as the first embodiment. Before the power position P, the tail seal replacement segments 10, 10, ... Are assembled, and after this is exposed to the rear surrounding ground G2 by the advance of the shield excavator 1,
A predetermined amount of drug solution is injected from the drug solution injection pipes 12, 12, ....

Further, after the chemical solution is injected, the tail seal replacement segments 10, 10, ...
2 are pulled out, and in place of this, a freezing pipe (ground solidifying means) 13, 13, ... Is inserted. Then, the freezing device (not shown) cools the freezing pipes 13, 13, ... And freezes the groundwater in the surrounding ground G2 'within a predetermined range.

After solidifying the surrounding ground G2 'within the predetermined range in this manner, the tail seals 7, 7, ... Are replaced in the same manner as in the first embodiment.

In the method of replacing the tail seals 7, 7, ... Of the shield excavator 1 described above, it is not sufficient to improve the ground in the surrounding ground G2 only by injecting a chemical solution, a freezing method is required, and there is groundwater flow. Even in the ground where the growth of frozen soil may be hindered, before the replacement of the tail seals 7, 7, ...
The ground water in the surrounding ground G2 'within a predetermined range is frozen. As a result, the circumference of the tunnel T can be sufficiently solidified over the entire circumference, so that the replacement work of the tail seals 7, 7, ... Is restricted by the replacement position P as in the first embodiment. Without it, it can be done safely.

In the first and second embodiments, the surrounding ground G2 is solidified by the chemical solution injection or the combined use of the chemical solution injection and the freezing, but of course, if sufficient ground improvement can be performed. , May be frozen only by the freezing tubes 13, 13, .... Further, the configuration of each part of the shield excavator 1 is not limited, and the above configuration can be applied to any type of shield excavator.

[0029]

As described above, according to the tail seal exchanging method for a shield excavator according to the first aspect of the invention, the tail seal exchanging segment having the opening communicating the inside and the outside is communicated with the tail seal before exchanging the tail seal. After exposing the tail seal replacement segment in the ground behind it by advancing the shield machine, solidify the surrounding ground through the opening of the tail seal replacement segment from inside the tunnel with the ground solidification means, and then the tail. The seal was replaced. In this way, by mounting the tail seal replacement segment and solidifying the surrounding ground by the ground solidifying means, the surrounding ground can be sufficiently solidified not from the ground surface but from inside the tunnel. At this time, by mounting the tail seal replacement segment over the entire circumference of the tunnel, the surrounding ground can be solidified over the entire circumference. Therefore, the replacement work of the tail seal can be safely performed without being restricted by the replacement position.

According to the tail seal exchanging method of the shield excavator of the second aspect, the ground solidifying means inserts the chemical liquid injection pipe into the opening of the tail seal exchanging segment, and from this chemical liquid injection pipe into the surrounding ground. It was configured to inject a chemical solution.
Thereby, the surrounding ground can be improved and solidified by the injected chemical solution. Further, in this way, by improving the surrounding ground not from the ground surface but from inside the tunnel, it is possible to reduce the amount of the chemical liquid used and suppress the ground improvement cost.

According to the tail seal exchanging method of the shield excavator of the third aspect, the freezing pipe is inserted into the opening of the tail seal exchanging segment, and the surrounding ground is frozen by the freezing pipe. As a result, the surrounding ground and groundwater can be solidified, ground improvement only by injecting a chemical solution is not sufficient, a freezing method is required, and there is groundwater flow, which may hinder the growth of frozen soil. Even if the tail seal is replaced, the work can be safely performed.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an example of a tail seal replacement method for a shield excavator according to the present invention.

[Explanation of symbols]

 1 Shield excavator 3 Skin plate 10 Tail seal replacement segment 10a Open hole 12 Chemical injection pipe (ground solidification means) 13 Freezing pipe (ground solidification means) S Segment T Tunnel G1 Ground G2 Surrounding ground

Claims (3)

[Claims] 1. When a tunnel is built on the rear side of the shield excavator by excavating the front ground by assembling the segments in a substantially cylindrical skin plate forming the outer shell of the shield excavator. Prior to replacing the tail seal provided in the tail portion of the skin plate for closing the gap between the outer peripheral surface of the assembled segment and the inner peripheral surface of the skin plate, a tail seal having an opening communicating the inside and the outside A replacement segment is continuously assembled to the previously assembled segment, and after the tail seal replacement segment is exposed in the ground behind it by advancing the shield excavator by further advancing the excavation, Solidify the surrounding ground from inside the tunnel through the opening of the tail seal replacement segment by ground solidification means So, tail seal replacing the shield excavator, which comprises exchanging the tail seal in the shield excavating machine thereafter. 2. The method of replacing a tail seal of a shield excavator according to claim 1, wherein the ground solidifying means inserts a chemical solution injection pipe into an opening of the tail seal replacement segment, and the surrounding ground is formed from the chemical solution injection tube. A tail seal exchanging method for a shield excavator, characterized in that a chemical solution is injected into the ground to improve the ground. 3. The method for exchanging tail seals of a shield excavator according to claim 1, wherein the ground solidifying means inserts a freezing pipe into an opening of the segment for exchanging tail seals.
A tail seal replacement method for a shield excavator, characterized in that the surrounding ground is frozen by the freezing pipe.