JPH1029648A - Injection hole plug for tunnel segment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To absorb the volumetric expansion of water even if a puddle of water formed outside an injection hole plug is solidified, in order to prevent the plug from being broken. SOLUTION: An injection hole plug 1 has a male screw 1A which can be screwed into a grout injection hole 2 provided on a segment side base material S1 while having a female screw 4 on an inner peripheral face to allow grout 3 to be injected in a state that the grout injection hole 2 is closed. In this case, the injection hole plug 1 for tunnel segments has a recess 7 having outward from a tunnel and also includes a non-water-permeable cushioning body 8 which can shrink in volume inside the recess 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention closes a grout injection hole provided in a segment-side base material while having a female screw portion on an inner peripheral surface so as to enable grout injection. The present invention relates to an injection hole plug for a tunnel segment having a male screw portion that can be screwed into a slidable state.

[0002]

2. Description of the Related Art In a conventional injection plug for a tunnel segment, connection between segments is terminated, grout is injected from the grout injection hole, and then screwed into the grout injection hole to close the grout injection hole. It is for doing. Some conventional injection hole plugs are simply formed by casting or the like.

[0003]

However, the above-mentioned conventional injection hole plug has the following problems. For example, in a portion connecting tunnels dug from two directions, a so-called freezing method of freezing nearby soil may be used in order to temporarily harden soft ground or to increase water stoppage. On the other hand, although grout has already been injected, groundwater and the like may accumulate outside the injection hole plug. In this case, when the freezing method is performed, there is an inconvenience that water accumulated outside the injection hole plug solidifies and expands, and the injection hole plug is damaged.

[0004] An object of the present invention is to solve the above-mentioned drawbacks of the prior art, and even if water accumulated outside the injection hole plug solidifies, it absorbs the volume expansion of the water and does not break. An object of the present invention is to provide an injection hole plug for a tunnel segment.

[0005]

[Means for Solving the Problems]

(Structure 1) As described in claim 1, the injection hole plug of the tunnel segment according to the present invention has a concave portion facing the outside of the tunnel, and a non-water-impregnable buffer capable of contracting volume. It is characterized in that it is provided in the interior of the. (Operation / Effect) According to the injection hole plug of the present configuration, the amount of water accumulated in the concave portion on the outside of the injection hole plug can be reduced, and water that cannot be prevented from pooling solidifies. Also, the volume expansion can be absorbed by the contraction of the buffer. Therefore, excessive pressure does not act on the injection hole plug, so that damage to the injection hole plug can be prevented, and water leakage from the injection hole into the tunnel can be prevented. In addition, the injection hole plug of the present invention is simply provided with the above-mentioned buffer inside the conventional injection hole plug, so that it is easy to improve and economical.

(Structure 2) In the injection hole plug of the tunnel segment according to the present invention, as described in claim 2, the buffer can be made of a resin having an independent space inside. (Operation / Effect) As the buffer of this configuration having an independent space inside, for example, a substantially cylindrical bag-shaped member molded of resin can be considered, but it is relatively difficult to manufacture a buffer of such a configuration. Easy. Moreover, it is easy to mount the buffer body formed alone inside the injection hole plug, and in this case, the injection hole plug can be used without any improvement from the conventional one. .

[0007]

Embodiments of the present invention will be described below with reference to the drawings. The injection hole plug 1 of the tunnel segment according to the present invention (hereinafter simply referred to as “injection hole plug 1”) is attached to a tunnel segment for constructing the inner peripheral wall of the tunnel, for example, as shown in FIG. This tunnel segment is, for example, a ductile segment,
Alternatively, any of a concrete segment, a steel segment and the like may be used. In the present embodiment,
An example will be described in which the antenna is attached to a ductile segment (hereinafter, simply referred to as “segment S”). In FIG.
The injection hole plug 1 is shown attached to a grout injection hole 2 (hereinafter simply referred to as “injection hole 2”) provided in the segment S. FIG. 2 shows an example in which the injection hole 2 is provided directly to the segment S.
Separately, a member provided with the injection hole 2 may be formed by attaching to the segment S. Therefore, hereinafter, the portion provided with the injection hole 2 is referred to as a segment-side substrate S1.

(Injection Hole) The injection hole 2 is provided at a substantially central portion of the segment S so as to penetrate in the thickness direction of the segment S. The injection hole 2 is for injecting the grout 3 into the gap between the excavated tunnel shaft and the segment S when the connection of the series of the segments S arranged in the circumferential direction of the tunnel is completed. On the peripheral wall portion of the injection hole 2, a female screw portion 4 for screwing the injection hole plug 1 is provided. The end of the injection hole 2 on the inner surface side of the tunnel is provided with the female screw portion 4.
The enlarged diameter hole portion 5 having an inner diameter even larger than the outer diameter of the above is continuously provided.

(Injection Hole Plug) As shown in FIGS. 2 and 3, the injection hole plug 1 has a male screw portion 1A and a flange portion 6, and closes the injection hole 2 with respect to the injection hole 2. It can be screwed into a state in which In a state after the injection hole plug 1 is screwed into the injection hole 2, the flange portion 6 is located inside the enlarged diameter hole portion 5, and the end face of the flange portion 6 on the inner side of the tunnel is The segment base material S1 is flush with the inner surface of the tunnel or retreated from the surface of the segment base material S1. A recess 7 is formed at the end of the injection hole plug 1 on the outside of the tunnel. The recess 7
Is formed from the end of the external thread portion 1A along the axis X of the injection hole plug 1 to a depth substantially equal to the length of the external thread portion 1A along the direction of the axis X. Have been. A buffer 8 that is non-immersible and that can contract in volume is attached to the recess 7. At the time of this mounting, it is desirable that the exposed side end of the buffer 8 should not be withdrawn as much as possible from the end of the male screw portion 1A. That is, after the injection hole plug 1 is mounted, the amount of water accumulated inside the injection hole 2 is reduced as much as possible to suppress the total volume expansion when water solidifies. The buffer 8 has a shape having an independent space 9 inside, for example, in a sealed bag shape, and is formed of resin, rubber, metal, or the like. At a boundary position between the external thread portion 1A and the flange portion 6, a sealing material 10 is attached so as to surround the external thread portion 1A. When the injection hole plug 1 is screwed into the injection hole 2, the sealing material 10 is sandwiched by the enlarged diameter hole portion 5 and the flange portion 6 to prevent groundwater and the like from entering the tunnel. It has a function to do. The injection hole plug 1
Can be produced by, for example, casting, or by machining a metal material or by injection molding a resin.

(Check valve) The injection hole plug 1 is connected to the injection hole 2
Prior to screwing into the injection hole 2, a check valve 1 is usually provided in the injection hole 2.
1 is screwed. The check valve 11 is, as shown in FIG.
A male screw part 11A is provided on the outer peripheral part, and a through hole 12 in the same direction as the extending direction of the injection hole 2 is provided in the inside.
The through-hole 12 enables the grout 3 to be injected, and a valve 13 is provided inside the through-hole 12. The valve body 13 has, for example, a semicircular shape, and two valve bodies 13 are attached to the support 14. The support 14 is, for example, a rod-shaped member, and
Is mounted on the inner wall of the through hole 12 so as to be located in the radial direction of the through hole. The two valve bodies 13 are swingable about the support 14. At the inner end of the check valve 11 on the inner side of the tunnel, a valve body stopper 15 projecting toward the center of the through hole 12 is provided over the entire circumference. Accordingly, grout injection toward the outside of the segment S can be permitted, and backflow of the grout 3 once injected can be prevented. The support 14 or the valve 13 can be formed using any material. Further, it is not always necessary to form both parts separately, and they may be integrally formed using a resin or the like. However, the check valve 11 has a check function for the grout 3, but does not have a check function for groundwater or the like.

(Function) The injection hole plug 1 is provided with the check valve 1
1 is screwed into the injection hole 2 to a predetermined position, and then screwed into the injection hole 2. The screwing of the injection hole plug 1 causes the sealing material 10 to undergo appropriate deformation due to the pressure between the stepped portion 5A of the enlarged diameter hole portion 5 and the flange portion 6 of the injection hole plug 1, and a water stopping function. Is carried out so that

Now, assume that the soil around the segment S is frozen using the freezing method. In this case, the grout 3 has already been injected to the outside of the segment S, but the cold heat reaches the segment S via the grout 3 as the soil freezes. As a result, the water accumulated outside the injection hole plug 1 is also cooled and solidified. However, although the volume of water expands, the buffer 8 can absorb the expanded amount of water by contracting its own volume. Therefore, excessive pressure is not applied to the injection hole plug 1, and breakage can be prevented.
The volume contraction of the buffer 8 is elastic or
Any of plastic ones may be used. However, the buffer 8 is made of, for example, a resin having a space inside,
If it is configured to be capable of elastic contraction, it can be used repeatedly. In addition, even when not repeatedly used, the injection hole plug 1 according to the present invention is the same as the conventional injection hole plug 1.
Since it is only necessary to mount the buffer body 8 inside the device, the improvement is easy and the cost increase accompanying the improvement can be slightly suppressed, which is economically advantageous.

In the description of the means for solving the above problems, reference is made to the drawings and, in order to facilitate comparison with the drawings, reference numerals are used, but the invention is limited to the configuration shown in the accompanying drawings. Not something.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a mounting position of an injection hole stopper according to the present invention.

FIG. 2 is a longitudinal sectional view showing a state where an injection hole stopper according to the present invention is attached.

FIG. 3 is an exploded perspective view showing a procedure for installing an injection hole stopper according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Injection hole plug of tunnel segment 1A Male screw part 2 Grout injection hole 3 Grout 4 Female screw part 7 Depression 8 Buffer 9 Independent space S1 Segment side substrate

Claims (2)

[Claims] 1. To enable the grout (3) to be injected,
A male screw having a female screw portion (4) on the inner peripheral surface and capable of being screwed into a grout injection hole (2) provided in the segment-side substrate (S1) so as to close the grout injection hole (2). An injection hole plug (1) for a tunnel segment having a portion (1A), comprising a recess (7) facing the outside of the tunnel and a non-water immersible and volume shrinkable buffer (8). An injection hole plug for a tunnel segment provided inside the recess (7). 2. The injection hole plug for a tunnel segment according to claim 1, wherein said buffer (8) is made of a resin having an independent space (9) inside.