JPH0378917B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a shield excavator for excavating a tunnel having a cocoon-shaped cross section.

BACKGROUND ART Conventionally, when excavating a tunnel with a wide cross section, for example, a two-lane subway tunnel, as shown in FIG. As shown in Figure 9, two small-diameter tunnels 52 were excavated in parallel. By the way, in the former case, the tunnel diameter becomes large, the face becomes easy to collapse, the cost of the excavator itself increases, and there is a lot of wasted space inside the tunnel. Since it requires a standalone shield excavator, it has disadvantages such as increased running costs and a longer construction period. As a method to eliminate such drawbacks, it is conceivable to make the cross-sectional shape of the tunnel into a shape in which two cylindrical tunnels are arranged on the left and right, and the opposing sides overlap each other with a predetermined width, that is, a cocoon shape. By the way, the 10th shield excavator excavates tunnels in a cocoon shape.
As shown in the figure, it is necessary to make the cross-sectional shape of the shield body 53 cocoon-shaped and to make the face plate 55 of the cutter head 54 provided at the front part of the shield body 53 spoke-like so as not to interfere with each other.

Problems to be Solved by the Invention As mentioned above, if the face plate of the cut head is spoke-shaped, it cannot adequately support the face.
There was a problem in that a large amount of soil preparation agent was required.

Therefore, an object of the present invention is to provide a shield tunneling machine that can solve the above problems.

Means for Solving the Problems In order to solve the above problems, the shield tunneling machine of the present invention connects at least two cylindrical shield main bodies in parallel with each other so that their opposing sides partially overlap. A shield main body having a cocoon-shaped cross section is constructed, and a rear cutter head having a circular face plate is rotatably supported at the front end of the one shield main body, and a rear pressure chamber partition is provided behind the rear cutter head, and the other shield main body is provided with a rear pressure chamber partition wall behind the rear cutter head. The front cutter head extends forward from the rear cutter head and rotatably supports the front cutter head which has a circular face plate at the front end of the other shield main body, and the front cutter head extends forward from the rear cutter head at a position between the front cutter head and the rear cutter head. A pressure chamber partition is provided.

Operation In the above configuration, when each cutter head is operated to move the shield body forward, a tunnel having a cocoon-shaped cross section is excavated. According to this structure, at least two cutter heads are arranged at different positions in the front and back, and the cutter head face plate is formed into a circular shape, so that even if the ground is soft and highly collapsible, the face can be sufficiently supported.

Embodiment Hereinafter, an embodiment of the present invention will be described based on the drawings. In Figures 1 to 3, 1 has a cocoon-shaped cross-section formed by connecting two cylindrical shield main bodies 2 and 3 in left and right parallel to each other so that their opposing sides partially overlap. This is the main body of the shield.
A rear cutter head 5 having a circular face plate 4 is attached to the front end of one of the shield body parts 2 through a holding cylinder 8 on which a rotating shaft 6 and a bearing (not shown) are mounted. A rear pressure chamber partition wall 10 is rotatably supported and forms a complete circular rear pressure chamber 9 with the face plate 4 at the rear thereof. The front end of the other shield main body 3 extends forward from the rear cutter head 5, and the front end of the other shield main body 3 has a front cutter head 12 having a circular face plate 11.
is rotatably supported via a holding cylinder 15 to which a rotating shaft body 13 and a bearing 14 are mounted, protruding from the rear thereof, and the front part is located between the front cutter head 12 and the rear cutter head 5. A front pressure chamber partition 17 is provided which forms a completely circular front pressure chamber 16 with the face plate 11 of the cutter head 12. Note that 18 is a rib for reinforcing the side wall of each pressure chamber 19, 16. Reference numerals 19 and 20 designate motors (electric or hydraulic) for rotating the respective cutter heads 5 and 12, and drive ring gears 21 fixed to the rear ends of the respective rotating shafts 6 and 13 via pinions 22. In addition, a plurality of slits 23 for taking in soil are formed radially in each of the face plates 4 and 11, and each slit 2
A large number of Katsuta bits 24 are attached to one side of 3. Although only a portion is shown in the drawing, it is attached to all of the slits 23.
Reference numeral 25 denotes an opening/closing plate for the slit 23, which is provided at a suitable position in each pressure chamber partition wall 10, 17 via a cylinder device 26 so as to be freely retractable.It is for supporting the face when the operation is stopped. In addition, each of the pressure chamber partition walls 10,
A mud feeding pipe 27 is connected to the upper central part of the pipe 17, and a mud draining pipe 28 is connected to the lower central part. Note that 29 is a propulsion jack that is arranged in large numbers along the inner periphery of the rear portion of the shield body 1, and 30 is a manlock provided on the pressure chamber partition walls 10 and 17 for allowing workers to enter and exit.

In the above configuration, when excavating a tunnel with a cocoon-shaped cross section, each motor 19, 20
Excavation can be carried out by rotating each cutter head 5, 12. At this time, slurry is injected into each pressure chamber 9, 16 from the mud feeding pipe 27 to support the face, and the excavated earth and sand is discharged from the mud draining pipe 28. Further, when the operation is stopped, the opening/closing plate 25 of the slit 23 is projected to support the face.

In addition, as mentioned above, since the pressure chambers 9 and 16 are independent on the left and right sides and are completely circular, for example, when a cocoon-shaped pressure chamber 31 is configured as shown in FIGS. 4 and 5. In addition, it is possible to prevent the strength of the end face 32a of the shield main body 32 that protrudes forward from becoming weak.

Incidentally, in the above embodiment, two cylindrical shield main bodies are arranged side by side in the horizontal direction, but for example, they may be arranged in parallel in the vertical direction, and as shown in FIGS. cylindrical shield main body part 41,
42 and 43 may be arranged side by side in the horizontal direction (or vertical direction). In this case, for example, the central cylindrical shield main body portion 42 is projected forward. Furthermore,
It is also possible to arrange four or more cylindrical shield main bodies in parallel.

Effects of the Invention According to the above configuration of the present invention, it is possible to excavate a tunnel with a cocoon-shaped cross section, so the overall tunnel width is narrower than in the case of excavating two circular tunnels. At the same time, the amount of excavation is reduced, which is advantageous in terms of economy. In addition, at least two cutter heads are placed, one at the front and the other at the rear, and the face plate of each cutter head is configured in a circular shape, so even if the ground is soft and highly collapsible, the face can be sufficiently covered. can be supported. Further, since a pressure chamber is provided for each cutter head, it is possible to prevent the strength of the front end of the other shield main body part that protrudes forward from becoming weak. Furthermore, since the left and right pressure chambers are installed independently, if the soil quality is different on the left and right sides, they can be dealt with separately, and
By creating a difference in the pressure within the pressure chamber, it is also useful for controlling the direction of the shield body.

[Brief explanation of drawings]

1 to 5 show an embodiment of the present invention, FIG. 1 is a horizontal sectional view, and FIG. 2 is a - of FIG. 1.
The arrow view, Figure 3 is the - arrow view of Figure 1, Figure 4.
The figure is a schematic plan view for explaining the defects, FIG. 5 is a view taken along the - arrow in FIG. 4, FIGS. 6 and 7 show other embodiments, and FIG. 7th
The figure is a front view, FIGS. 8 to 10 show a conventional example, FIGS. 8 and 9 are sectional views of a tunnel, and FIG. 10 is a front view of a cocoon-shaped shield tunneling machine. 1... Shield main body, 2, 3... Cylindrical shield main body part, 4, 11... Face plate, 5... Rear cutter head,
9... Rear pressure chamber, 10... Rear pressure chamber bulkhead, 12...
Front cutter head, 16...front pressure chamber, 17...front pressure chamber partition.

Claims (1)

[Claims] 1 At least two cylindrical shield main bodies are connected in parallel with each other so that their opposing sides partially overlap to form a shield main body with a cocoon-shaped cross section, and a circular shape is attached to the front end of one of the shield main bodies. A rear cutter head having a face plate is rotatably supported, and a rear pressure chamber partition is provided behind the rear cutter head, and the front end of the other shield body extends forward from the rear cutter head, and a circular shape is provided at the front end of the other shield body. 1. A shield excavator, which rotatably supports a front cutter head having a face plate, and further includes a front pressure chamber partition wall provided at a position between the front cutter head and the rear cutter head.