JP2851522B2 - Shield excavator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield excavator,
In particular, the present invention relates to a sealing device for shortening the time required for connecting a shaft and a shield excavator.

[0002]

2. Description of the Related Art A conventional connection method will be described with reference to FIGS. In FIG. 8, reference numeral 1 denotes a concrete shaft based on a caisson foundation, which is buried in a ground 2. A portion 5 of the side wall 3 of the shaft 1 which is removed for connection with the shield excavator 4 includes an inner portion 5A made of concrete having high strength and an outer portion 5 made of mortar having low strength.
B The inner part 5A is a shield excavator 4
Is made thin as long as necessary strength can be secured before connection, and is hereinafter referred to as a temporary wall. The side wall 3 of the shaft 1 penetrates a ground improvement agent injection passage 6 that opens to the ground 2 side, and is connected to a mortar tank (not shown) via a valve 7.

When the shield excavator 4 digs through the tunnel and reaches the shaft 1 as shown in FIG. 8, it excavates the mortar portion 5B as it is, and stops excavation just before the temporary wall 5A as shown in FIG. In this state, the mortar 8 is injected into the ground 2 from the shaft 1 side through the injection passage 6 and further from the shield excavator 4 side, and the shield body (skin plate) 9
And the ground around the segment 10 behind it. This ground improvement is performed when removing the temporary wall 5A.
This is to prevent earth and sand and water from flowing into the shaft 1 from 1.

After the mortar is injected and the ground improvement is completed, the temporary wall 5A is removed from the shaft 1 by another machine 12 as shown in FIG. As a result, shaft 1
Since the shield excavator 4 penetrates and connects both,
The shield body 9 is left as a tunnel structure, and other devices such as the cutter head 13 are carried away, and an appropriate post-processing is performed. After the removal of the temporary wall 5A, the shield excavator 4 may be advanced until the hood 14 at the tip of the shield body 9 enters the shaft 1 as shown in FIG.

[0005]

As a method for preventing a large amount of sediment and water from flowing in when removing the temporary wall 5A, as described above, conventionally, the mortar 8 is simply injected into the ground 2 to improve the ground. is there. Therefore, the shield body 9 and the segment 10
Until the mortar 8 is injected over a wide area around the ground and the ground is sufficiently hardened, the work of removing the temporary wall 5A and the work of moving the shield main body 9 cannot be performed, and the construction period is long. In the case of large tunnels, mortar injection takes more than one month.

SUMMARY OF THE INVENTION In view of the above-mentioned prior art, an object of the present invention is to provide a shield excavator provided with a sealing device capable of shortening a period required for connecting a shaft and a shield excavator.

[0007]

SUMMARY OF THE INVENTION A shield excavator according to the present invention includes an annular recess formed in the outer periphery of a front portion of a shield body of a shield excavator, and a front portion fixed in the annular recess and arranged annularly. It is characterized by comprising a brush seal, an annular cover slidably mounted in the annular recess, and a moving device for moving the annular cover.

[0008]

Before removing the temporary wall (inner portion) of the shaft connection portion from the inside of the shaft, the annular cover is moved when the annular recess is located in a hole formed by excavating the outer portion. Thereby, the rear part of the annular brush seal projects out of the shield main body from the annular concave portion, and seals between the shaft and the shaft. Therefore, even if the work of removing the temporary wall is performed in parallel during the injection of the ground improvement agent, it is possible to prevent earth and sand and water from flowing into the shaft, thereby shortening the construction period.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 4 shows the overall schematic configuration. As shown in FIG. 4, around the front outer periphery of the shield body 9 of the shield excavator 4,
An annular sealing device 15 is provided so that the rear part of the brush seal can protrude from the shield body 9. On the other hand, of the side wall 3 of the shaft 1, the connection portion 5 with the shield excavator 4 is composed of a concrete inner portion, that is, a temporary wall 5A, and a mortar or sponge or rubber outer portion 5B, as in the related art. The thickness of 5A is about 1/4 of the thickness of the side wall 3.

The details of the sealing device 15 will be described with reference to FIGS. The annular seal device 15 includes an annular brush seal 17, an annular cover 18A, and a jack 18B. An annular recess 1 is formed on the outer periphery of the front part of the shield body 9
The brush seals 17 are arranged in two rows on the annular support member 20 at the bottom. The brush seal 17 is fixed only at the front part and the rear part is free. When the cover 18A is retracted by the jack 18B and the annular concave part 19 is opened, the rear part of the annular seal 19
It protrudes from the inside to the outside of the shield body 9. Annular cover 18A
Is provided on the outer periphery of the shield body 9 so as to be slidable in the front-rear direction, and opens and closes the annular concave portion 19. A jack 18B is provided between the annular cover 18A and the shield body 9 with a fixture 18C.
Are provided as appropriate via.

As shown in FIG. 3, the annular brush seal 17 includes a plurality of brush seal pieces 17A having a wider rear portion than a front portion in which a large number of wires are arranged in a brush shape.
The annular support member 2 is arranged so that the rear part partially overlaps.
0 fixed by bolts or welding 21.

In addition, between the two rows of brush seals 17,
A filler inlet 22 is provided in the annular support member 20, and a filler tank 23 for a grease-like filler 23 is connected to this through a valve 22A, so that the filler 23 can be discharged. In the drawing, reference numeral 25 denotes a support member such as a cutter head drive mechanism, and 26 denotes a mortar injection passage on the shield excavator side.

With the above arrangement, when the cover 18A is positioned forward due to the extension of the jack 18B, the brush seal 17 does not protrude from the annular concave portion 19,
When the cover 18A is retracted and opened by the jack 18B,
The rear portion is free to project outside the shield main body 9 to perform a sealing operation. In this case, the valve 22A is opened and the filler 2
By discharging 3, the sealing effect is further enhanced.

Next, a method of connecting a shield excavator and a shaft according to the present invention will be described with reference to FIGS.

As a connection work, when the shield excavator 4 reaches the shaft 1, the valve 7 on the shaft 1 and the valve 16 on the shield excavator 4 are opened as shown in FIG. And the injection of the mortar 8 is started.

Next, during injection of the mortar, as shown in FIG. 5, the shield excavator 4 is advanced, and excavation of the connection portion 5 of the shaft 1 is started. During this excavation, after the annular sealing device 15 enters the excavated hole 5C, the rear part of the brush seal of the annular sealing device 15 is projected outward of the shield body 9 to seal the gap between the shaft 1 and the shaft 1. For example, as shown in FIG. 5, when the excavation of the outer portion 5B has just been completed, the jack 18B is shortened, the cover 18A is retracted, and the annular concave portion 19 is opened.
The advancing of the shield excavator 4 is stopped with the rear part of the brush seal 17 protruding. At this time, the valve 22A is opened to discharge the grease-like filler 23.

Then, as shown in FIG. 6, the concrete temporary wall 5A of the connection portion 5 is removed from the inside of the shaft 1 by the machine 12 while the mortar is being injected and the sealing is performed by the sealing device 15.

After the removal of the temporary wall 5A, the shield excavator 4 is advanced and stopped as necessary until the hood 14 of the shield body 9 just enters the shaft 1 as shown in FIG.

After the temporary wall 5A is removed or after the shield excavator 4 advances, the injection of the mortar 8 is continued and stopped when the required amount is reached. During this time, appropriate post-processing such as removal of the cutter head 13 and the like and secondary winding work inside the shield body 9 are performed. Even if the annular sealing device 15 is left as it is,
Or you may remove it.

[0021]

The shield excavator of the present invention is provided with an annular brush seal protruding from the outer periphery of the front part of the shield body, so that the inner periphery of the connection between the shield body and the shaft during injection of the ground improvement agent. The work of removing the inner part (temporary wall) of the connection part by sealing the space can be performed in parallel, and the connection period between the shaft and the shield excavator can be shortened.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing one embodiment of the present invention.

FIG. 3 is a development view of an annular brush seal.

FIG. 4 is a diagram showing a method of connecting a shaft with a shaft by the shield excavator of the present invention.

FIG. 5 is a view showing a method of connecting a shaft with a shaft by the shield excavator of the present invention.

FIG. 6 is a diagram showing a method of connecting a shaft with a shaft by the shield excavator of the present invention.

FIG. 7 is a diagram showing a method of connecting a shaft with a shaft by the shield excavator of the present invention.

FIG. 8 is a diagram showing a conventional technique.

FIG. 9 is a diagram showing a conventional technique.

FIG. 10 is a diagram showing a conventional technique.

FIG. 11 is a diagram showing a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vertical shaft 2 Ground 3 Side wall 4 Shield excavator 5 Connection part 5A Inside part (temporary wall) 5B Outside part 5C Hole 6,26 Injection passage 7,16 Valve 8 Ground improvement agent (mortar) 9 Shield body 10 Segment 13 Cutter head 14 Hood 15 Sealing device 17 Annular brush seal 18A Annular cover 18B Jack 19 Annular concave

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-176991 (JP, A) (58) Field surveyed (Int.Cl. ⁶ , DB name) E21D 9/06 301

Claims (1)

(57) [Claims] 1. An annular recess formed on the outer periphery of a front portion of a shield body of a shield excavator, a brush seal having a front portion fixed in the annular recess and arranged annularly, and slidably mounted in the annular recess. A shield excavator comprising: an annular cover; and a moving device for moving the annular cover.