JPH0842708A - Packing device for blocking flow of fluid - Google Patents

Abstract

PURPOSE:To block between two cylinders, flowing-in of liquid for raising the inner pressure of an outer hollow packing by enabling pressurized water to be filled between respective packings. CONSTITUTION:A plurality of hollow cylindrical packings 12a, 12b expanding by being filled with compressed air therein are installed between the outer surface of a cylindrical casing 6 and the inner surface of a ring frame 11. Water pressure is applied to a space 17 between two adjacent hollow ring-like packings, so as to pressurize the sides of both packings.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention, for example, when starting tunnel excavation by the shield construction method, the present invention is carried into a vertical shaft built to a predetermined depth, and the side wall is opened by cutting the lower side wall of the vertical shaft. Prevents the flow of liquid between two cylindrical surfaces, such as when preventing underground water from flowing into the shaft through the gap between the casing of the shield excavator and the opening on the bottom wall of the shaft. Regarding packing device.

[0002]

2. Description of the Related Art As an example of the use of a packing for blocking the flow of liquid between two cylindrical surfaces, there is a case of tunnel excavation by a shield construction method. The shield method is widely used as a method of excavating a tunnel in the ground. Therefore, as a conventional packing example for blocking the flow of liquid, the case of the shield construction method will be described below as an example.

5 and 6 show the state of the equipment at the starting point of tunnel excavation by the conventional shield construction method.
Is a vertical sectional view showing an outline, and FIG. 6 is an enlarged view of a lower portion thereof.

In FIGS. 5 and 6, 1 is the ground where a tunnel is to be excavated, and 2 is a vertical shaft wall constructed by building a large concrete bottomed cylinder in the ground. The excavator 3 is suspended from the upper part of the vertical shaft. Lower or assemble in the shaft and place at the bottom of the shaft. The excavator 3 rotates the cutter 4 to cut open the vertical shaft wall and enter the ground 1. As the excavator 3 moves out of the vertical shaft, a segment 5 is laid behind the excavator, and the excavator pushes the segment 5 with a hydraulic device to move laterally (see FIG. 5).
To the left). Inside the cylindrical casing 6 forming the outer surface of the excavator 3, accessory devices such as a motor 7 for driving the cutter 4, a screw conveyor 8 for discharging excavated earth and sand, and a hydraulic cylinder 9 for pushing the segment 5 are provided. . An anchor block 10 is formed in the same body at the portion of the vertical shaft wall 2 where the excavator 3 cuts, and the casing 6 is formed in the anchor block 10.
A larger ring frame 11 is attached. Ring frame 11
Between the inner surface of the and the outer surface of the casing 6 of the excavator, one rubber hollow ring-shaped packing 12 that is expanded by sending compressed air is inserted. 13 is an entrance packing that is provided between the inner end of the ring frame 11 and the casing 6 to prevent water that could not be blocked by the hollow ring-shaped packing 12 from flowing into the shaft, and 14 is a rear end of the casing 6. Segment 5
It is a packing for preventing water from flowing into the casing from between.

When the ground 1 surrounding the vertical shaft wall 2 contains a large amount of water, when the excavator 3 cuts the vertical shaft wall 2 and advances to the ground 1, the anchor block 1 is opened from the opening of the vertical shaft wall 2.
0 between the inner surface and the outer surface of the excavator casing 6,
Water tries to flow into the vertical shaft. When the water content of the ground 1 is large and it is expected that a large amount of water will flow into the shaft with the excavation of the excavator 3, it is possible to inject the soil improvement agent into the ground in front of the shaft wall in the direction of the water advance. The construction is proceeded by excavating this part after reducing the ground to form the improved ground 22, but if the ground improvement work is not completed,
There is a risk of water flowing into the shaft. Packing 12, 13
Aims to prevent the ingress of this water.

[0006]

When the air pressure is increased, the hollow ring-shaped packing 12 that expands when air pressure is applied to the casing 6 and the ring-shaped frame 11 strongly presses the casing 6 and the ring-shaped frame 11 to inflow water. The effect of blocking is strengthened. The upper and lower sides and the outer side (anchor block side) of the hollow ring-shaped packing 12 are supported by the circular frame 11, the casing 6 and the water pressure of the water to flow in, but on the inner side (the entrance packing 13 side). However, since the external force that supports this does not act, it expands freely, so there is a limit to increasing the air pressure in the hollow ring-shaped packing 12 and increasing the water inflow prevention effect.

The present invention is intended to enhance the internal pressure of the hollow ring-shaped packing 12 to enhance the water inflow preventing action.

[0008]

According to the present invention, a plurality of hollow ring-shaped packings are provided between an outer surface of a casing 6 of an excavator and an inner surface of a ring frame 11, and pressurized water having an appropriate pressure is provided between the packings. The present invention is a packing device for preventing inflow of a liquid that can be injected and that can increase the internal pressure of the outer hollow ring-shaped packing.

[0009]

The two adjacent hollow ring-shaped packings interposed between the outer surface of the casing 6 of the excavator and the inner surface of the ring frame 11 are adjacent to each other.
Water pressure acts between the individual packings, and the outer ring-shaped packing on the outer side is suppressed by this water pressure on the outer surface on the inner side.Therefore, the inner pressure of the hollow ring-shaped packing is increased to form a circle with the casing outer surface in the vertical direction. The strong contact with the inner surface of the wheel frame enhances the effect of blocking the inflow of water. The water pressure injected between both hollow ring-shaped packings can be increased by the amount of the water inflow prevention effect of the inner hollow ring-shaped packing, so the inner pressure of the outer hollow ring-shaped packing is increased by this amount to increase the vertical wall opening. The effect of blocking the inflow of water from can be enhanced.

[0010]

1 to 4 show an embodiment of the present invention in the case of a shield construction method, FIG. 1 is a vertical sectional view of a vertical shaft bottom similar to FIG. 6, FIG. 2 is an enlarged view of part A of FIG. 3 is a cross-sectional view of a hollow ring-shaped packing showing the action of air pressure and water pressure, and FIG. 4 is a cross-sectional view showing a configuration example of the hollow ring-shaped packing. The same parts as those of the conventional structure are designated by the same reference numerals and the description thereof will be omitted. Next, this embodiment will be described.

Two rubber hollow ring-shaped packings 12a and 12b are interposed between the inner cylindrical surface of the ring frame 11 and the outer cylindrical surface of the casing 6 of the excavator 3 which are connected to the anchor block 10 by the bolts 15. The compressed air is supplied by the air supply pipes 16, respectively. Both packings 12
Pressurized water is supplied to a space 17 between a and 12b by a water supply pipe 18.

As shown in FIG. 3, when compressed air is fed into the inner hollow ring-shaped packing 12b to such an extent that it does not expand excessively inward, the packing 12 is compressed by the fed compressed air.
If b is pressed against the casing 6 and the ring-shaped frame 11 by a force of F, a frictional force αF acts between them and the packing 12b to prevent the packing 12b from moving laterally against the water pressure (α Is the friction coefficient), and this friction force is 2αF
Immobilizes the packing 12b. As described above, since there is the immobile inner hollow ring-shaped packing 12b, the outer packing 12a, which is supported on the inner side by the pressurized water applied to the space 17, is supported to bulge inward. Therefore, the internal pressure of the packing 12a can be increased by this amount, and the water inflow prevention effect of the packing 12a can be increased.
That is, the inner pressure of the hollow ring-shaped packing 12b on the inner side is set to such an extent that the packing 12b does not expand excessively, and the inner pressure of the outer packing 12a is set higher than this to enhance the water inflow prevention action. . This pressure adjustment is for the air supply pipe 1
The valves 19a and 19b provided on the valve 6 and the valve 20 provided on the water supply pipe 18 are used for adjustment.

FIG. 4 shows an example of the structure of the hollow ring-shaped packings 12a, 12b. A ring-shaped rubber band having thickened both side edges 21a, 21b is bent into a tubular shape, and the ring-shaped frame 11 is hermetically sealed with bolts 23, 23. It is installed.

In the embodiment shown in FIGS. 1 to 4, two hollow ring-shaped packings are arranged side by side to prevent the outer packing from bulging inward.
The inner pressure of this packing is increased to enhance the water inflow prevention effect of the hollow ring-shaped packing.
By arranging more than one piece and applying water pressure between each packing, the packing internal pressure can be gradually increased from the inner side to the outer side, so the inner pressure of the outermost hollow ring-shaped packing is The water inflow prevention effect can be enhanced by significantly increasing it as compared with the case of using it alone. The water inflow prevention effect of the hollow ring-shaped packings arranged from the outermost side to the inner side gradually weakens as the inner pressure of the packing gradually lowers, but the momentum for inflowing water is also inward. Since it gradually weakens as it goes to the side, the water inflow prevention action of the entire packing device formed by the plurality of hollow ring-shaped packings becomes high.

In this embodiment, the shield type excavator was used as an example to prevent the inflow of water.
It can also be used in the general case of blocking the flow of liquid between two cylindrical surfaces. The material of the hollow ring-shaped packing is not limited to rubber, and any material that is flexible and swells by the internal pressure and can press against the cylindrical surface to prevent the flow of liquid such as water and oil can be used.

[0016]

EFFECTS OF THE INVENTION By using a plurality of flexible hollow ring-shaped packings in parallel, the internal pressure of the outermost packing can be increased, so that the liquid in the outermost packing is prevented from flowing. The effect can be enhanced. The liquid flow blocking effect of the plurality of hollow ring-shaped packings as a whole is also enhanced.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing two hollow ring-shaped packings provided between an excavator casing and a ring frame according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is a sectional view showing a force acting on a hollow ring-shaped packing.

FIG. 4 is a cross-sectional view showing a configuration example of a hollow ring-shaped packing.

FIG. 5 is a vertical cross-sectional view showing the outline of the state of the equipment at the excavation start point of the conventional excavator.

FIG. 6 is a vertical cross-sectional view of the device at the bottom of the vertical shaft.

[Explanation of symbols]

 1 Ground 2 Vertical shaft 3 Excavator 4 Cutter 5 Segment 6 Casing 7 Motor 8 Screw conveyor 9 Hydraulic cylinder 10 Anchor block 11 Wheel frame 12, 12a, 12b Hollow ring packing 13, 14 Packing 15 Bolt 16 Air supply pipe 17 Space 18 Water supply pipe 19a, 19b valve 20 valve 21a, 21b edge 22 improved ground 23 bolt

Claims (1)

[Claims] 1. A packing device for preventing liquid flow between two cylindrical surfaces, wherein a plurality of flexible hollow ring-shaped packings, into which compressed air is supplied, are arranged in parallel, and between adjacent packings. A packing device for blocking the flow of a liquid, which is filled with pressurized water that supports a side surface of a hollow ring-shaped packing on the inflow side of the flowing water.