JPH0248555Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to a closure plug for a backfill injection port of a concrete segment for tunnel lining.

[Prior art and its problems]

Generally, in the shield method for tunnel construction, backfilling material is injected into the tail void that occurs between the shield segment assembled in a ring shape and the ground. This backfilling material is injected through an injection port provided in the segment, but after work, the injection port must be closed to maintain the atmospheric pressure in the work chamber and prevent groundwater from penetrating.

In the old days, a wedge-shaped wooden stopper was simply pushed into the injection port from the inside with a hammer, but this method did not maintain sufficient air pressure or watertightness in the work chamber, and it took time to attach and remove the stopper, so the method shown in Figure 1. - A closure plug as shown in FIG. 3 has already been proposed.

That is, the closure plug 1 is integrally formed of synthetic resin, and a threaded portion 3 is formed on the outer periphery of a bottomed cylindrical body 2. A flange 5 is provided on the outer periphery of a bottom plate 4 of the cylindrical body 2. A rotating grip part 6 in the shape of a square projection is formed at the center of the outer surface of.

In such a closure plug 1, as shown in FIG. 4, a steel sleeve 9 is fitted to the concrete segment 7 to form an injection port 8, and a female thread formed on the inner peripheral surface of the tip end of the sleeve 9 is formed. It is screwed through.

However, in such a closure stopper 1, when waterproof mortar 10 is injected as a backfilling material from the injection port 8 and the lid is closed, freezing water 16 poured out from the mortar 10 flows around the stopper 1, creating a gap in this area. This may cause a significant loss of watertightness. Further, it is technically difficult to remove the closed stopper 1 once again and refill the gap, and this results in a lack of reliability.

[Purpose of invention]

The purpose of the present invention is to eliminate the disadvantages of the conventional example, and to provide a closing plug for the backfilling inlet of a tunnel segment, which can easily and quickly fill the void created by water generation when the inlet is closed with the plug. It is about providing.

[Key points of the idea]

However, according to the present invention, the purpose of the lever is to provide a stopper in which a threaded portion is formed on the outer circumference or inner circumferential surface of a bottomed cylinder, and a small diameter through hole having a thread groove is provided in the bottom plate of the stopper; This is achieved by screwing together a small-diameter stopper and later filling the gap in the injection port through this small-diameter through-hole.

[Example of idea]

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Fig. 5 is a longitudinal sectional front view showing an embodiment of the closure plug of the present invention, and Fig. 6 is a top and bottom view of the same, in which the same components as in Figs. 1 to 3 showing the conventional example are given the same reference numbers. did.

In the figure, reference numeral 1 indicates a closure plug, which has a threaded portion 3 on the outer periphery of a bottomed cylinder 2, and a flange 5 on the outer periphery of the bottom plate 4 of the cylinder 2.
This is the same as the conventional example in that a rotation grip 6 in the shape of a rectangular projection is formed in the center of the outer surface of the bottom plate 4 in a bulging manner.

A small diameter through hole 1 is formed in the bottom plate 4 of such a closure plug 1.
1 is formed on the wall surface of this hole 11.
2. A small-diameter plug 14 having a threaded portion 13 screwed into the threaded groove 12 was provided. In addition,
The material of the stopper 1 may be synthetic resin as in the conventional example, but it may also be made of steel.
The same is true. Further, a rotation groove 15 is formed on the bottom surface of the stopper 14, and the small diameter through hole 11 may be provided at any position on the bottom plate 4, but in order not to impair the overall strength of the stopper 1, it is necessary to The center of the rotating grip 6, which is the thickest part, is desirable.

FIG. 7 is a partially cutaway front view showing another embodiment of the present invention, in which the closure plug 1' is of a type that protrudes inward and is attached, and the cylinder body 2' has a threaded part 3' formed on the inner periphery. This is the case. Also in such a closure plug 1', the bottom plate 4' has a small diameter through hole 11' and this hole 11'.
A small-diameter plug 14' for closing may be formed by threaded connection.

Next, to briefly explain how to use it, a backfilling material such as waterproof mortar is injected from the injection port 8 in FIG. ing. Furthermore, since this small-diameter stopper 14 has no outwardly protruding portion, it does not interfere with the work of setting the closure stopper 1 in any way.

After some time has elapsed since the injection port 8 was closed with the stopper 1 in this way, and when it appears that water has accumulated, the small-diameter stopper 1 is removed with a screwdriver etc. while the stopper 1 is still attached.
If only the small diameter plug 4 is removed and a chemical solution or the like is injected through the small diameter through hole 11, the gap near the stopper 1 can be reliably closed, and the rest can be closed as before with the small diameter stopper 14.

[Effect of idea]

As mentioned above, the closure plug for the backfilling inlet of the tunnel segment of the present invention has a smaller diameter plug that can be screwed onto the bottom plate of the plug, so the backfilling inlet can be closed with the closure plug as the main body part. If there is a gap in the inlet after it is closed, it can be filled by injecting a chemical solution etc. through the small diameter stopper, and there is no need to remove the entire thing, which saves time and improves the reliability of inlet blockage. There is no risk of damaging the

[Brief explanation of the drawing]

Figure 1 is a partially cutaway front view of a conventional closure plug.
Figure 2 is a top view of the same as above, Figure 3 is a bottom view of the same as above, Figure 4 is a bottom view of the same as above.
The figure is a longitudinal sectional front view showing an example of use, Fig. 5 is a longitudinal sectional front view showing one embodiment of the closure plug of the present invention, Fig. 6 is a bottom view of the same, and Fig. 7 is another embodiment of the closure stopper of the present invention. It is a partially cutaway front view showing the usage state of the example. 1, 1'... Closing plug, 2, 2'... Cylindrical body, 3,
3'... Threaded part, 4, 4'... Bottom plate, 5... Flange, 6... Rotating grip part, 7... Concrete segment, 8... Inlet, 9... Sliver, 10
...Mortar, 11...Small diameter through hole, 12...Thread groove, 13...Threaded portion, 14...Small diameter plug, 15...
...Groove for rotation, 16...Freezing water.

Claims (1)

[Scope of utility model registration request] In a stopper in which a threaded portion is formed on the outer circumference or inner circumferential surface of a bottomed cylinder, a small-diameter through hole having a thread groove is provided in the bottom plate of the stopper, and the small-diameter stopper is screwed into this hole. Features a closure plug for the backfill inlet of the tunnel segment.