JPH07103772B2 - Shield excavator - Google Patents

Description

TECHNICAL FIELD The present invention relates to a shield excavator, and more particularly to a sealing device for shortening the work period for connecting a shaft and a shield excavator.

<Prior Art> A conventional connection construction method will be described with reference to FIG.

In the figure, reference numeral 1 is a concrete shaft made of caisson foundation, which is buried in the ground 2. The portion 5 of the side wall 3 of the shaft 1 that is removed for connection with the shield excavator 4 is an inner portion 5A made of concrete and having high strength.
And a low strength outer part 5B made of mortar. The inner portion 5A is made thin as far as necessary strength can be secured before connecting the shield excavator 4, and is hereinafter referred to as a temporary wall.

Further, a side wall 3 of the shaft 1 penetrates a ground improvement agent injection passage 6 that opens to the side of the natural ground 2 and is connected to a mortar tank (not shown) via a valve 7.

Then, the shield excavator 4 digs through the tunnel and
When the shaft 1 is reached as shown in FIG. 4A, the mortar portion 5B is excavated as it is, and the excavation is stopped before the temporary wall 5A as shown in FIG. 4B. In this state, the mortar 8 is injected into the ground 2 through the injection passage 6 from the vertical shaft 1 side and further from the shield excavator 4 side, and the shield body (skin plate) 9
And the ground around the segment 10 behind it is improved.
This ground improvement is to prevent inflow of earth and sand and water from the gap 11 into the shaft 1 when removing the temporary wall 5A.

After the injection of mortar and the ground improvement by it,
As shown in FIG. 4 (c), the temporary wall 5A is removed from the shaft 1 by another machine 12. As a result, the shield excavator 4 penetrates the vertical shaft 1 and connects the two, so that the shield body 9 is left as a tunnel structure and the other cutter head 13 is left.
Carry away such equipment and perform appropriate post-treatment. The temporary wall
After removing 5A, as shown in FIG. 4 (d), the shield body 9
Shield excavator 4 until the hood 14 at the tip enters the shaft 1
May move forward.

<Problems to be Solved by the Invention> As a method for preventing a large amount of sediment or 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, after the mortar 8 has been injected over a wide area around the segment 10 and the ground has hardened sufficiently, the work of removing the temporary wall 5A and the work of advancing the shield body 9 cannot be performed, which takes a long time. For large tunnels, it takes more than a month to inject mortar.

The present invention has been made in view of the above-mentioned conventional art, and an object of the present invention is to provide a shield excavator provided with a seal device that can reduce a construction period required for connecting a vertical shaft and a shield excavator.

<Means for Solving the Problems> A shield excavator according to the present invention includes an annular recess formed on the outer periphery of a front part of a shield body of the shield excavator, an annular seal having elasticity inserted into the annular recess, and the annular recess. A plurality of jacks arranged circumferentially on the bottom of the annular recess inside the seal are provided.

<Operation> Before removing the temporary wall (inner portion) of the vertical shaft connecting portion from the inside of the vertical shaft, the jack is extended in a state where the hole formed by excavating the outer portion has an annular seal. As a result, the annular seal expands in diameter and projects to the outside of the shield body to seal the gap with the vertical shaft.

Therefore, even if the removal work of the temporary wall is performed in parallel during the injection of the ground improvement agent, it is possible to prevent the inflow of earth and sand and water into the shaft,
The construction period can be shortened.

<Examples> Examples of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 3 (a) shows the overall schematic configuration. As shown in FIG. 3A, on the outer periphery of the front part of the shield body 9 of the shield excavator 4,
An annular sealing device 15 is provided so that it can project from the shield body 9. On the other hand, in 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 an outer portion 5B made of mortar or sponge or rubber, as in the conventional case. The thickness of 5A is about 1/4 of the thickness of the side wall 3.

Details of the sealing device 15 will be described with reference to FIGS. 1 and 2.
The annular seal device 15 is an annular seal 17 made of rubber or synthetic resin.
And a large number of jacks, for example screw jacks 18. An annular recess 19 is formed on the outer circumference of the shield body 9, a large number of jacks 18 are circumferentially arranged on an annular support member 20 at the bottom of the shield main body 9, and an annular seal 17 is installed on the outer circumference thereof. Between the tip of each jack 18 and the annular seal 17, a seal pressing plate 21 is provided separately so as to apply a uniform force. In the figure,
22 is a jack mounting seat, 23 is a screw portion of the jack, and 24 is a nut portion thereof. Further, 25 is a supporting member such as a cutter head drive mechanism, and 26 is a mortar injection passage on the side of the shield excavator.

The annular seal 17 enters the annular recess 19 and does not project when the jack 18 is in a shortened state, and the screw portion 23 of the jack 18 is rotated by an appropriate actuator or manual operation to extend the jack 18 to expand the annular seal 17. By doing so, the sealing operation is performed.

Next, with reference to FIG. 3, a method of connecting the shield excavator and the vertical shaft of the present invention will be described.

As the connection work, when the shield excavator 4 reaches the vertical shaft 1, as shown in FIG. 2A, the valve 7 on the vertical shaft 1 side and the valve 16 on the shield excavator 4 side are opened to make a ground improvement agent in the ground 2. Then, the injection of mortar 8 is started.

Next, during the mortar injection, the shield excavator 4 is moved forward as shown in FIG. 3 (b), and excavation of the connecting portion 5 of the vertical shaft 1 is started.

During this excavation, after the annular seal device 15 enters the excavated hole 5C, the annular seal device 15 is projected to the outside of the shield body 9 to seal the space between the shaft 1 and the vertical shaft 1. For example, FIG. 3 (b)
As described above, when the excavation of the outer portion 5B is just completed, the jack 18 is extended to operate the annular sealing device 15, and the advance of the shield excavator 4 is stopped in this state.

Then, while the mortar is being injected and sealing by the sealing device 15 is being performed, the concrete temporary wall 5A of the connecting portion 5 is removed by the machine 12 from inside the vertical shaft 1 as shown in FIG. 3 (c).

After removing the temporary wall 5A, if necessary, until the hood 14 of the shield body 9 just enters the shaft 1 as shown in FIG. 3 (d),
The shield excavator 4 is advanced and stopped.

The injection of the mortar 8 is continued even after the removal of the temporary wall 5A or after the advance of the shield excavator 4 thereafter, and the injection is stopped when the required amount is reached. During this time, the cutter head 13 and other parts are removed, and the shield body 9
Perform appropriate post-processing such as secondary winding work. The annular sealing device 15 may be left as it is or may be removed.

<Effects of the Invention> Since the shield excavator of the present invention is provided with the annular seal device that can project to the outer periphery of the front part of the shield body, the inner periphery of the connecting portion between the shield body and the vertical shaft during injection of the ground improvement agent. It is possible to seal the spaces and perform the work of removing the inner portion (temporary wall) of the connection portion in parallel, and it is possible to shorten the connection construction period between the shaft and the shield excavator.

[Brief description of drawings]

1 and 2 are sectional views showing an embodiment of the present invention, and FIG.
FIG. 4 is a diagram showing a method of connecting a vertical shaft with a shield excavator of the present invention, and FIG. 4 is a diagram showing a conventional technique. In the drawing, 1 is a shaft, 2 is a ground, 3 is a side wall, 4 is a shield excavator, 5 is a connecting part, 5A is an inner part (temporary wall), 5B is an outer part, 5C is a hole, and 6 and 26 are injections. Passage, 7 and 16 are valves,
8 is a ground improvement agent (mortar), 9 is a shield main body, 10 is a segment, 13 is a cutter head, 14 is a hood, 15 is a sealing device, 17 is an annular seal, 18 is a jack, and 19 is an annular recess.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Takagi 1-25-1 Nishishinjuku, Shinjuku-ku, Tokyo Taisei Corporation (72) Inventor Kiyomi Sasaki 1-1, Wadasaki-cho, Hyogo-ku, Kobe-shi, Hyogo No. 1 Mitsubishi Heavy Industries, Ltd. Kobe Shipyard (72) Inventor Takao Matsumoto 1-1-1, Wadasakicho, Hyogo-ku, Hyogo Prefecture Kobe City Mitsubishi Heavy Industries, Ltd. Kobe Shipyard

Claims (1)

[Claims] 1. An annular recess formed in the outer periphery of the front part of a shield body of a shield excavator, an annular seal having elasticity inserted into the annular recess, and a circular shape at the bottom of the annular recess inside the annular seal. A shield excavator comprising a large number of jacks.