JPH07180467A - Connecting method for vertical shaft and shield machine - Google Patents

Abstract

PURPOSE:To shorten the connecting period of a vertical shaft and a shield machine by providing a sealing device at the outside portion of the vertical shaft in advance, sealing the gap between the outer periphery of a shield main body and the vertical shaft after the excavation of the outside portion is started, and removing a temporary wall during mortar grouting. CONSTITUTION:A valve 7 on a vertical shaft 1 side and a valve 16 on a shield machine 4 side are opened, and mortar is grouted into the natural ground 2. The shield machine 4 is advanced during the mortar grouting, and the excavation of the connecting portion 5 of the vertical shaft 1 is started. The gap between the outer periphery of a shield main body 9 and the inner periphery of the vertical shaft 1 is sealed with sponge or rubber which is a sealing device 15 itself. The outside portion 5c is excavated during the grouting of mortar and the sealing by the sealing device 15, then the concrete temporary wall 5A of the connecting portion 5 from the vertical shaft 1 is removed with a machine. The shield machine 4 is advanced and stopped until the hood 14 of the shield main body 9 just enters the vertical shaft 1, and the grouting of mortar is continued until it reaches the required quantity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for connecting a shaft and a shield excavator, and more particularly to an improvement for shortening the construction period.

[0002]

2. Description of the Related Art A conventional connecting method will be described with reference to FIGS. In FIG. 8, 1 is a concrete shaft based on a caisson foundation, which is buried in the ground 2. Of the side wall 3 of the shaft 1, the portion 5 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.
It is made of B and. The inner part 5A is a shield excavator 4
It is made thin as far as necessary strength can be secured before connection, 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.

When the shield excavator 4 digs through the tunnel and reaches the vertical shaft 1 as shown in FIG. 8, the mortar portion 5B is excavated as it is, and the excavation is stopped before the temporary wall 5A as shown in FIG. 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 improving the ground around the segment 10 behind it. This ground improvement is performed by removing the gap 1 when removing the temporary wall 5A.
This is to prevent the inflow of earth and sand and water from shaft 1 into the shaft 1.

When the injection of mortar and the ground improvement by it are 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 through and both are connected,
The shield main body 9 is left as a tunnel structure, other devices such as the cutter head 13 are carried away, and appropriate post-treatment is performed. After removing 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 vertical shaft 1 as shown in FIG.

[0005]

As described above, as a method for preventing a large amount of sediment or water from flowing in when removing the temporary wall 5A, 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
Only after the mortar 8 has been poured over a wide range of the surroundings 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 requires a long construction period. For large tunnels, it takes more than a month to inject mortar.

In view of the above-mentioned conventional technique, the present invention has an object to provide a construction method capable of shortening the construction period required for connecting the shaft and the shield excavator.

[0007]

In the connection method according to the present invention, a sealing means is provided in advance in a soft outer portion of a connection portion with a shield excavator, and after the start of excavation of the outer portion and a ground improvement agent. The hard inner part of the connection part is removed during the injection.

[0008]

In the present invention, since the sealing means is provided, in parallel with the injection of the ground improvement agent, of the connecting portion of the side wall of the vertical shaft, the outer portion of the connecting portion of the vertical shaft is excavated by the shield excavator and the inner portion from the inside of the vertical shaft. To remove. During this time, the sealing means blocks the inflow of earth and sand and water into the shaft. As a result, even if it takes a long time to inject the ground improvement agent, the connection work proceeds in parallel with this and the entire construction period is shortened.

[0009]

Embodiments of the present invention will be described below with reference to FIGS.

1 to 4 show an embodiment of the present invention, in which the inner portion, that is, the temporary wall 5A, of the connection portion of the shaft 1 with the shield excavator 4 is made of concrete as in the prior art, but the outer portion thereof. 5C is a soft elastic material made of sponge or rubber,
It is the sealing device 15 itself. The thickness of the temporary wall 5A is about 1/4 of the thickness of the side wall 3.

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

Next, during the injection of mortar, as shown in FIG. 2, the shield excavator 4 is advanced to start excavating the connecting portion 5 of the vertical shaft 1. At this time, the sponge or rubber, which is the sealing device 15 itself, is clogged between the outer circumference of the shield body 9 and the inner circumference of the vertical shaft 1 to perform a sealing action.

Then, after the outer portion 5C is excavated while the mortar is being injected and the sealing device 15 is performing sealing,
The concrete temporary wall 5A of the connecting portion 5 is removed from the vertical shaft 1 by the machine 12. See FIG.

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

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, appropriate post-treatments such as removal of the cutter head 13 and secondary winding work in the shield body 9 are performed.

FIG. 5 shows another embodiment, which is a concrete portion 5D of the vertical shaft 1 surrounding an outer portion 5C made of sponge or rubber.
Two rows of annular recesses 17 are provided on the inner circumference of the elastic tube 18, and an elastic tube 18 is annularly arranged therein, and a pressure fluid source (not shown) is connected to the tube 18 via a valve 19. A mortar injection port 20 is provided between the annular recesses 17. With these, in addition to the above-described sealing action of the outer portion 5C itself, the sealing effect is further enhanced.

As the connecting work, when the tip of the shield body 9 passes through the left tube 18, the valve 19 is opened to supply the pressure fluid. As a result, the diameter of the tube 18 is expanded and protrudes from the annular recess 17, and the outer circumference of the shield body 9 is pressed to seal. Further, thereafter, mortar 21 is injected from the injection port 20 between the tubes 18 to enhance the sealing action. The temporary wall 5A is removed while the sealing is performed in this manner.

FIG. 6 shows another embodiment. Instead of the tube 18 shown in FIG. 5, two rows of annular seals 22 having a chevron cross section are provided on the inner circumference of the concrete portion 5D of the vertical shaft 1. In this case, when the tip portion of the shield body 9 passes through the left annular seal 22, it is only necessary to inject the mortar 21 from the inlet 20, and while these and the inner portion 5C themselves are performing sealing, the temporary wall Remove 5A.

FIG. 7 shows still another embodiment, in which a reinforcing member 23 such as a brush seal or an iron plate is annularly arranged so as to reinforce the inner peripheral side of the tube 18 of FIG. Since the brush seal has elasticity, its front portion may be fixed to the inner circumference of the concrete portion 5D of the vertical shaft 1. In the case of an iron plate, it is advisable to attach its front part rotatably, such as by pin connection. Reinforcement member 2 for both brush seals and iron plates
In No. 3, the small pieces are arranged in an annular shape, and the small pieces are overlapped with each other to maintain the sealing effect. The connection work in the case of FIG. 7 is the same as that in FIG.

[0020]

According to the present invention, the sealing means seals the outer circumference of the shield body and the inner circumference of the connection portion of the shaft, and the connection portion is removed in parallel during the injection of the ground improvement agent. The construction period is shortened.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the method of the present invention.

FIG. 2 is a diagram showing an embodiment of the method of the present invention.

FIG. 3 is a diagram showing an embodiment of the method of the present invention.

FIG. 4 is a diagram showing an embodiment of the method of the present invention.

FIG. 5 is a diagram showing another embodiment.

FIG. 6 is a diagram showing another embodiment.

FIG. 7 is a diagram showing another embodiment.

FIG. 8 is a diagram showing a conventional method.

FIG. 9 is a diagram showing a conventional method.

FIG. 10 is a diagram showing a conventional method.

FIG. 11 is a diagram showing a conventional method.

[Explanation of symbols]

 1 Vertical shaft 2 Ground 3 Side wall 4 Shield excavator 5 Connection part 5A Inner part (temporary wall) 5C Outer part 6,20 Injection passage 7,16,19 Valve 8 Ground improvement agent (mortar) 9 Shield body 10 Segment 13 Cutter head 14 Hood 15 Sealing Device 17 Annular Recess 18 Tube 21 Mortar 22 Annular Seal 23 Reinforcing Member

Claims (1)

[Claims] 1. A method of connecting a shaft and a shield excavator by removing a connecting part composed of a relatively hard inner part and a soft outer part of a side wall of the shaft, wherein shield excavation is performed on the outer part of the shaft. It is characterized in that a sealing means between the outer periphery of the shield body of the machine and the shaft is provided in advance, and the inner part of the shaft is removed after the start of excavation of the outer part of the shaft and during the injection of the ground improvement agent. Connection method between vertical shaft and shield excavator.