JPH07180472A - Shield machine - Google Patents

Abstract

PURPOSE:To shorten the connecting period of a vertical shaft and a shield machine. CONSTITUTION:A circular recess 19 is formed on the outer periphery of the front section of a shield main body 9, a tube 17 is circularly fitted, and a pressure fluid source 18 is connected to the tube 17 via a valve 21. A pressure fluid is fed to the tube 17 before the temporary wall 5A of a vertical shaft 1 is removed, and the tube 17 is expanded in diameter to seal the gap with a vertical shaft l before the temporary wall 5A of the vertical shaft 1 is removed. The temporary wall 5A is removed during the grouting of mortar, and the connecting period of the vertical shaft 1 and the shield machine 4 is shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a shield excavator,
In particular, the present invention relates to a sealing device for shortening the work period for connecting the shaft and the shield excavator.

[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, it is an object of the present invention to provide a shield excavator equipped with a seal device which can shorten the construction period required for connecting the shaft and the shield excavator.

[0007]

A shield excavator according to the present invention comprises an annular recess formed on the outer periphery of a front part of a shield body of the shield excavator, and an annular hollow seal having elasticity inserted into the annular recess. A pressure fluid source connected via a valve is provided inside the hollow seal.

[0008]

[Operation] Before removing the temporary wall (inner part) of the shaft connection part from the inside of the shaft, open the valve with the hollow seal in the hole made by excavating the outer part and pressurize the fluid inside the hollow seal. Put in. As a result, the diameter of the hollow seal expands and protrudes 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, and shorten the construction period.

[0009]

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

FIG. 4 shows an overall schematic structure. As shown in FIG. 4, 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, and among the side walls 3 of the vertical shaft 1,
The connection portion 5 with the shield excavator 4 is composed of an inner portion made of concrete, that is, a temporary wall 5A, and an outer portion 5B made of mortar, sponge, or rubber, as in the conventional case, and the thickness of the temporary wall 5A is the thickness of the side wall 3. It is about 1/4 of that.

Details of the sealing device 15 will be described with reference to FIGS. The sealing device 15 includes an annular hollow seal (tube) 17 made of rubber or synthetic resin, and a pressure fluid source 18 connected to the hollow seal 17 via a valve 21. An annular recess 19 is formed on the outer periphery of the front portion of the shield body 9, and the hollow seal 17 is provided along the annular support member 20 at the bottom.
Are installed in a ring. The hollow seal 17 has a constricted portion 17a, and a reinforcing iron plate 22 is provided along the inner peripheral side of the constricted portion 17a and is fixed to the support member 20. Also, hollow seal 1
In order to increase the reliability of the protection and housing of the shield 7, an annular cover 23 is provided in the opening of the annular recess 19 so as to be movable in the front-rear direction of the shield body 9, and the cover 24 is opened and closed by a jack 24. Normally, the cover 23 is closed at the forward position to close the annular recess 19, and when the diameter of the hollow seal 17 is expanded, the cover 23 is retracted to supply the pressure fluid. In the figure, 18A is a flow path of pressure fluid, 25 is a support member such as a cutter head drive mechanism, and 26 is a mortar injection passage on the side of a shield excavator.

With the above construction, the hollow seal 17 normally enters the annular recess 19 and does not project, and the valve 21 is opened to supply the pressure fluid to the inside to expand the diameter and perform the sealing operation.

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

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. 5, the shield excavator 4 is advanced to start excavating the connecting portion 5 of the vertical shaft 1. 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 gap with the vertical shaft 1. For example, as shown in FIG. 5, when the excavation of the outer portion 5B has just been completed, the cover 23, if present, is opened by the jack 24, and then pressure fluid is supplied into the hollow seal 17 to operate the sealing device 15. Then, the advance of the shield excavator 4 is stopped in this state.

While the mortar is being injected and the sealing device 15 is still performing the sealing, the concrete temporary wall 5A of the connecting portion 5 is removed from the shaft 1 by the machine 12 as shown in FIG.

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

The mortar 8 continues to be injected even after the removal of the temporary wall 5A or after the advance of the shield excavator 4 and 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. Even if the annular sealing device 15 is left as it is,
Or you may remove it.

[0019]

Since the shield excavator of the present invention is provided with the annular hollow seal which can be projected by the pressure fluid on the outer periphery of the front portion of the shield body, the shield body and the shaft are connected to each other during the injection of the ground improvement agent. By sealing the inner circumference, the inner part (temporary wall) of the connecting part can be removed in parallel.
It is possible to shorten the connection period between the vertical shaft and the shield excavator.

[Brief description of drawings]

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

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

FIG. 3 is a sectional view showing an embodiment of the present invention.

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

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

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

FIG. 7 is a diagram showing a method of connecting a vertical shaft with a 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]

 1 Vertical shaft 2 Ground 3 Side wall 4 Shield excavator 5 Connection part 5A Inner part (temporary wall) 5B Outer part 5C Hole 6,26 Injection passage 7, 16, 21 Valve 8 Ground improvement agent (mortar) 9 Shield body 10 Segment 13 Cutter head 14 Hood 15 Sealing device 17 Annular hollow seal 18 Pressure fluid source 19 Annular recess

Claims (1)

[Claims] 1. An annular recess formed on the outer periphery of a front part of a shield body of a shield excavator, an annular hollow seal having elasticity inserted into the annular recess, and a hollow seal which is connected to the inside of the hollow seal via a valve. A shield excavator comprising a pressure fluid source.