JP2971312B2 - 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 has two rows of annular recesses formed on the outer periphery of a front portion of a shield body, and a shape in which the front portion is fixedly annularly disposed in each annular recess. A seal made of a memory alloy, a heating device for heating the seal, and the shield body between the annular concave portion.
The seal is provided with a filler inlet provided on an outer periphery, and the seal memorizes a shape in which a rear portion projects outside the annular concave portion.

[0008]

[Action] Before removing the temporary wall (inside portion) of the shaft connection portion from the inside of the shaft, two rows of rings are formed by drilling the outer portion.
Each seal is heated while the seal in the concave portion is inserted. As a result, each seal returns to the memorized state, and the rear portion of each seal projects outward of the shield body to double seal between the seal and the shaft. Also, an annular concave from the filler inlet
Discharge the filler between the sections and seal the gap between the shaft and the shaft.
To In this way, the connection between the shield body and the shaft
Each seal made of shape memory alloy seals double between the inner circumferences.
And filling discharged from the filler inlet into the annular recess
Since the agent is also sealed, the sealing effect is improved. 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 as to 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. 5A thickness is side wall 3
Is about 1/4 of the thickness.

The details of the sealing device 15 will be described with reference to FIGS. The annular seal device 15 includes an annular seal 17 made of a shape memory alloy, an electric heater 18A and a power supply 18B thereof.
Consists of Then, two rows of annular concave portions 19 are formed on the outer periphery of the front part of the shield body 9, and the seal 17 is arranged on the annular support member 20 at the bottom. Further, a heater 18A is arranged on the back side of the seal 17. The seal 17 is fixed to the annular support member 20 only at the front part, is free at the rear part, and memorizes such a shape that the rear part protrudes from the annular concave part 19 by heating.

More specifically, as shown in FIG. 3, the seal 17 has a large number of seal pieces 17A having a narrower front portion than the rear portion.
The rear part is partially overlapped and bolts or welds 21
It is fixed by. The seal piece 17A may be a wire brush (a so-called brush seal) in which a large number of wires made of a shape memory alloy are arranged in addition to the plate itself.

In FIGS. 1 and 2, a filler inlet 22 is provided between the two annular concave portions 19, and is connected to a tank 24 with a grease-like filler 23 via a valve 22A. In FIG. 2, reference numeral 25 denotes a support member such as a cutter head drive mechanism, and reference numeral 26 denotes a mortar injection passage on the shield excavator side.

With the above configuration, the annular seal 17 does not protrude into the annular concave portion 19 when not heated, returns to the shape memorized by the heating of the heater 18A, and performs the sealing operation with the rear portion protruding outward. In this case, by discharging the filler 23 using the valve 22A, the sealing effect is further improved.

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 heater 18 of the annular sealing device 15
A is actuated to heat the seal 17 and protrude out of the shield body 9 to seal between the shaft 1 and the shaft. For example,
As shown in FIG. 5, when the excavation of the outer portion 5B has just been completed, the heater 18A is energized to operate the annular sealing device 15, and in this state, the advance of the shield excavator 4 is stopped.

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]

Effects of the Invention shield excavator of the present invention together with comprises a shape memory alloy of the seal operated by pressurized heat in the annular recess of the two rows formed on the front outer periphery of the shield body, the shape memory
Filler filling between annular recesses where each alloy seal is installed
By providing a mouth, the connection between the shield body and the shaft
Each seal made of shape memory alloy seals double between the inner circumferences of
And the filler discharged between the annular recesses from the filler inlet.
Since the filler is also sealed, the sealing effect is improved. Follow
Therefore, during the injection of the ground improvement agent, the inner periphery of the connection portion between the shield body and the shaft can be effectively sealed, and the inner portion (temporary wall) of the connection portion can be removed in parallel. Connection period between the shield and the 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 a 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 7,16,22A Valve 8 Ground improvement agent (mortar) 9 Shield body 10 Segment 13 Cutter head 14 Hood 15 Sealing device 17 Annular seal 18A Heater 18B Power supply 19 Annular recess

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-176991 (JP, A) JP-A-63-181898 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) E21D 9/06 301

Claims (1)

(57) [Claims] 1. A two-row annular recess formed on the outer periphery of a front part of a shield body of a shield excavator, a seal made of a shape memory alloy having a front part fixed in each annular recess and annularly arranged. A heating device for heating the seal ;
Filler provided on the outer periphery of the shield body in between
A shield excavator comprising a mouth , wherein the seal memorizes a shape in which a rear portion projects outside the annular recess.