JPH0988486A - Grouting hole in concrete segment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the adhesion between concrete and a threaded pipe which is made of a synthetic resin and carries thread ridges on both the internal and external surfaces and, at the same time, to eliminate the possibility of rust by forming a grouting hole by burying the threaded pipe in a concrete segment. SOLUTION: Multiple thread ridges are formed on the internal surface of a synthetic resin pipe 1 and thread ridges having diameters which are slightly larger than those of the thread ridges formed on the internal surface are formed on the external surface of the pipe 1 in corresponding to the thread ridges on the internal surface. A synthetic resin plug 6 is screwed in one end of the threaded pipe 1 and a megaphone-like synthetic resin pipe 7 is put in the pipe 1 from the other end and fitted to the internal surface of the pipe 1 of the other end. When the pipe 1 is buried in a concrete segment 10 in the thickness direction, the adhesion between the pipe 1 and concrete of the concrete segment can be secured and no rust nor electric corrosion occurs.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grout hole for a concrete segment for tunnel lining.

[0002]

2. Description of the Related Art A grout injection hole for backfilling a concrete segment is required for tunnel lining, and there is an internal threaded pipe for screwing a hanging metal fitting used at the time of assembly in the approximate center of the segment. This female screw tube forms a grout hole that doubles as a grout injection hole for backfilling.

In the conventional concrete segment, a steel pipe is exclusively used as a female screw pipe, and a steel pipe having a thread on the inner surface and welded with an anchor bar on the outer surface is embedded in the concrete segment to form a grout hole. There is.

[0004]

In the conventional grout hole formed by burying a steel pipe, (1) it is necessary to weld an anchor bar to the steel pipe in order to improve adhesion between the steel pipe and concrete, which is troublesome. (2) Steel pipes are easily corroded and rust occurs. (3) Electrolytic corrosion easily occurs on the steel pipe. There are problems such as.

The present invention has been devised to solve these problems.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a threaded synthetic resin pipe having threads corresponding to the inner surface not only on the inner surface but also on the outer surface is embedded as a female threaded pipe in a concrete segment to form a grout hole. The above problems are solved all at once.

That is, according to the present invention, "the inner surface is formed so as to form a thread of a multi-threaded screw, and the outer surface is formed so as to form a thread having a diameter slightly larger than that of the inner surface so as to correspond to the thread of the inner surface. A grout hole for a concrete segment, which is characterized in that a threaded synthetic resin pipe having a thread portion of substantially constant thickness is embedded along the thickness direction of the concrete segment to form a female screw pipe. " Is. By embedding the threaded synthetic resin pipe according to the present invention into a female threaded pipe, (1) the thread is exposed as it is on the outer surface of the female threaded pipe, and the irregularities of the thread are filled with concrete. As a result, sufficient adhesion between the female threaded pipe and concrete is secured, and the use of anchor bars is unnecessary. Moreover, the threaded portion of the female threaded pipe is reinforced by the hardened concrete.
(2) Since the female screw pipe is a synthetic resin pipe, there is no concern about rusting or electrolytic corrosion. The effect is brought.

However, since the screw thread of the synthetic resin pipe is not so sharp, there is a concern that the screwing force may be insufficient with a normal single-thread screw, so it is necessary to use a multi-thread screw having two to four threads.

In the present invention, a synthetic resin pipe with a screw thread may be buried over substantially the entire length in the thickness direction of the concrete segment to form a grout hole, but there is no problem.
As described in claim 2, a synthetic resin plug is attached to one end (inner surface side of the concrete segment) of the threaded synthetic resin pipe by screwing, and the other end (outer surface side of the concrete segment) is made of synthetic resin megaphone. It is preferable to attach objects by fitting to form a synthetic resin assembly, and bury the assembly along the thickness direction of the concrete segment to form a grout hole.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An example of an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an example of a synthetic resin molded product which is embedded in a concrete segment to form a grout hole according to the present invention. (A) is a perspective view of an example of a synthetic resin pipe with a thread, b) is a perspective view of an example of a synthetic resin stopper,
(C) is a perspective view of an example of a synthetic resin megaphone, (d)
FIG. 4 is a cross-sectional view of an example of a mounting portion of a synthetic resin megaphone-like object to a screwed synthetic resin tube.

FIG. 2 is a cross-sectional view of an example in which the assembly of the synthetic resin molded products shown in FIG. 1 is embedded along the thickness direction of the concrete segment to form a grout hole.

In this example, the threaded synthetic resin pipe 1 comprises a threaded portion 3 of a three-threaded screw in which threads are spirally formed from the thread start points 2a, 2b, 2c at one end, and a circular pipe portion and a conical portion following the screw portion 3. 5 has a ridge 4 on the outer surface of the circular pipe portion, and the conical portion 5 is formed in a shape of being split into a cross shape.

The synthetic resin stopper 6 is formed by a disk 6a and a threaded portion 6b of a triple thread screw.

The synthetic resin megaphone 7 is shaped like a divergent megaphone, and has a groove 7a on the inner surface of the base.

Using these three types of synthetic resin molded products, a synthetic resin plug 6 is screwed into the threaded synthetic resin tube 1 and the concave groove 7a of the synthetic resin megaphone 7 is threaded synthetically. A synthetic resin assembly is produced by fitting the resin tube 1 into the convex strip 4 on the outer surface of the circular pipe portion.

During the production of the concrete segment 10,
This assembly is embedded in the approximate center of the concrete segment 10 along the thickness direction. In this burying, the both ends of the assembly are usually designed not to be exposed on the surface of the concrete segment 10 but to be covered with the thin concretes 8 and 9, but both ends of the assembly are exposed to the surface of the concrete segment 10. It may be buried so as to be exposed. Further, instead of the thin concretes 8 and 9, thin mortar may be used.

The formed grout holes are used as follows.

(1) When assembling a concrete segment, after removing the thin concrete 8 on the inner surface side, the synthetic resin stopper 6 is turned and removed, and the tip of the assembling hanging metal fitting is screwed to the mark. After the assembling is completed and the assembling hanging metal fitting is removed, the synthetic resin stopper 6 is screwed again. However, if the backfill material is to be injected immediately after assembly, leave it removed.

(2) The synthetic resin plug 6 is removed, and the thin wall concrete 9 on the outer surface side is impacted with an appropriate tool to break it, and the backfill material is injected. The cross-shaped pieces of the conical portion 5 of the threaded synthetic resin tube 1 prevent backflow of the backfill material, and the synthetic resin megaphone 7 serves to facilitate smooth injection of the backfill material.

[0021]

The present invention is constructed as described above and has the following effects.

(1) Since the screw thread is exposed as it is on the outer surface of the female threaded pipe, and the irregularities of the screw thread are filled with concrete, a sufficient adhesive force between the female threaded pipe and the concrete is secured and the anchor is formed. The use of muscle is unnecessary. Moreover,
The threaded portion of the female threaded pipe is reinforced by hardened concrete.

(2) Since the female screw tube is a synthetic resin tube, there is no concern about rusting or electrolytic corrosion.

[Brief description of drawings]

FIG. 1 shows an example of a synthetic resin molded product embedded in a concrete segment to form a grout hole,
(A) is a perspective view of an example of a synthetic resin tube with a thread, (b) is a perspective view of an example of a synthetic resin stopper, (c) is a perspective view of an example of a synthetic resin megaphone, and (d) is. It is sectional drawing of the example of the attachment part to the synthetic resin pipe with a screw thread of a synthetic resin megaphone thing.

FIG. 2 is a cross-sectional view of an example in which an assembly of synthetic resin molded products is embedded along the thickness direction of a concrete segment to form a grout hole.

[Explanation of symbols]

1 ... Synthetic resin pipe with screw thread, 2a, 2b, 2c ... Screw thread starting point, 3 ... Screw part, 4 ... projection, 5 ... Cone part, 6 ... Synthetic resin plug, 6a ... ... disk, 6b ... screw part, 7 ... synthetic resin megaphone, 7a ... concave groove, 8
…… Inner surface thin-walled concrete, 9 …… Outer surface thin-walled concrete, 10 …… Concrete segment.

Claims (2)

[Claims] 1. A substantially constant wall thickness formed so that an inner surface forms a thread of a multi-threaded screw and an outer surface corresponds to the thread of the inner surface and forms a thread having a diameter slightly larger than the thread of the inner surface. A grout hole for a concrete segment, wherein a threaded synthetic resin pipe having a threaded portion is embedded along the thickness direction of the concrete segment to form a female screw pipe. 2. A synthetic resin assembly in which a synthetic resin stopper is attached to one end of the threaded synthetic resin pipe according to claim 1 by screwing, and a synthetic resin megaphone-like object is attached to the other end by fitting. A grout hole for a concrete segment, wherein the grout hole is embedded along the thickness direction of the concrete segment to form a cavity having an internally threaded pipe.