JPS5923117Y2 - Grout hole structure with muddy water backflow prevention plug - Google Patents

Description

[Detailed Description of the Invention] This invention relates to prevention of backflow of muddy water in grout holes provided in, for example, R and C (reinforced concrete) segments.

Below, R, C segment I and concrete construction members are shown below.
Explain using.

Most of the current I/N channels are R, C segment I
・Uses

This is because the R and C segments have excellent features not found in other tunnel construction methods in terms of workability, strength, cost, etc.

However, this tunnel construction method using R and C segments also has various problems that should be improved through future research.

One example of this is the backflow of muddy water from grout holes.

This muddy backflow from the grout hole is caused by groundwater that collects behind the R and C segment walls, which are assembled in a ring shape and are dug into the tunnel.
It was feared that grouting work would be extremely difficult in areas with strong muddy water backflow, causing a significant delay in the construction period.

This idea was devised in view of the above circumstances, and its purpose is to form a tapered part at the outer opening of the grout hole of the R and C segments, and to block this taper part by muddy water backflow pressure. Another object of the present invention is to provide a grout hole structure with a muddy water backflow prevention stopper, which is provided with a temporary frame that is opened by the injection pressure of the grouting material, and thereby minimizes muddy water backflow during grouting work.

Hereinafter, one embodiment of this invention will be described in detail based on the drawings.

The figure shows the grout hole structure in R and C segments I.

In the figure, reference numeral 1 indicates R and C segments, and 2 indicates a grout hole.

The inside of this grout hole 2 is reinforced by a socket 4 with a screw 3 formed on the inner wall, and one side of this socket 4,
In other words, the insides of the R and C segments 1 are closed with plugs (lids).

On the other hand, the other end of this socket 4 is fixed at a position slightly retracted from the outer surfaces of the R and C segments 1, and the inner periphery of the hole 5 between this end and the outer surface is a tapered part covered with a metal ring 6. Finished as 7.

This tapered portion 7 allows a temporary frame 8, which will be described later, to sit comfortably, and also makes surface contact with the temporary frame 8, thereby perfecting the water-stopping effect.

Inside this taper part 7, there is a metal temporary which is fixed by the narrow part of the taper part 7 and has a circumferential surface that comes into close surface contact with the surface of the taper part 7 and closes the grout hole 2. Frame 8
is embedded.

Note that this temporary frame 8 is for closing the grout hole until the grouting agent is injected.

On the back side of the bottom of this temporary frame 8, there are a plurality of elastic protrusions 8a...
... are formed to protrude outward so as to abut on the inner circumferential surface of the grout hole 2, and to be able to spring onto the hole ends of the sockets I to 4 and hold the temporary frame 8 when closed (solid line state in the figure). ing.

Note that the tip of the elastic protrusion 8a is bent inward.

In addition, in order to prevent the temporary frame 8 from falling during connection work, excavation, etc., the temporary frame 8 should be prevented from detaching from the vicinity of the taper part 7 and the grout hole 2 via, for example, a thin wire (made of steel) 8b. It is configured as follows.

During grouting, the temporary frame 8 is filled with grouting material (injecting agent).
It comes off due to the inflow of the grout, and the grout is filled in the released state, and after the grout is injected, the solidified grout prevents muddy water from flowing back.

Next, the operation of this invention will be explained using the above configuration.

First, the grout holes 2 of the R and C segments 1 installed in the tunnel are closed by the temporary frame 8.

As described above, the temporary frame 8 is kept closed by the elastic force of the plurality of elastic protrusions 8a provided on the bottom back side of the temporary frame 8.

When attaching the temporary frame 8, for example, when the grout hole 2 is large, each elastic protrusion 8a of the temporary frame 8 is expanded outward, and when the grout hole 2 is cramped, each elastic protrusion 8a is expanded outward. Attach the temporary frame 8 by sliding it inward.

Even if the elastic protrusion 8a is deformed in this way,
Since the tip of each elastic protrusion 8a is bent inward, the temporary frame 8 can be easily pushed into the grout hole 2 without the elastic protrusion 8a getting caught on the end of the grout hole 2.

In addition, since the temporary frame 8 has a peripheral surface that makes close surface contact with the tapered portion 7, even if the size of the grout hole 2 changes slightly, there is no problem in closing the lid because the only change is the size of the contact surface. .

Therefore, the temporary frame 8 has the same size regardless of the size of the grout hole 2 (in the illustrated example, the molding error of the socket 4 provided in the grout hole 2), even if the size of the grout hole is different to a certain extent. The grout hole 2 can be reliably covered by the temporary frame 8.

That is, according to the temporary frame 8 of the present invention, there is no need to create a dedicated cap for each grout hole of different size, and one temporary frame 8 can be applied to various grout holes 2, and the cost can be reduced accordingly. obtain.

In addition, the muddy water that has accumulated on the outside of R and C segments l-1 is removed from the temporary frame 8.
This prevents water from entering the grout hole 2, that is, from backflowing out.

In this state, the temporary frame 8 is pressed by muddy water on its back, and the circumferential surface of the temporary frame 8 is in close surface contact with the taper part 7, so it is more firmly in contact with the taper part 7, and is slightly The holes are designed to completely shut off water without loosening due to vibrations, etc.

Therefore, internal grouting work etc. can be done smoothly.

However, when the grouting work starts, the grout I.
The temporary frame 8 that has closed the hole 2 is pushed out by the injected grout.

Although the above embodiment was explained as a temporary frame for closing the grout holes of R and C segments, the same effect can be obtained even if it is applied to steel segments and other concrete construction members having various grout hole structures. It is not limited only to R and C segments.

Further, in the above embodiment, a metal ring was used to form a part of the taper for both sealing and reinforcement, but synthetic resin or the like may also be used, and the material is not particularly limited.

Since this invention has the above-mentioned structure and function, it is possible to prevent muddy water backflow during grouting work,
The grouting work is very easy to perform, and therefore the construction period can be significantly shortened and construction costs can be kept low.

On the other hand, since it is extremely simple in structure, it is very easy to form and process, and does not require many parts, and by bending the elastic protrusions of the temporary frame, it can be easily installed in grout holes of different sizes. Therefore, it can be provided at low cost.

In addition, the temporary frame is held at the end of the grout hole by the elastic force of the elastic protrusions, and the tips of the elastic protrusions are bent inward, making it easy to fit into the grout hole.
It has various practical effects, such as improving work efficiency on site.

[Brief explanation of the drawing]

The drawing is a longitudinal cross-sectional view showing an embodiment of the invention, showing a main part thereof. 1... Concrete construction members (R, C segments), 2... Grout hole, 5...
Hole opening, 7... Part of the taper, 8... Temporary frame, 8a... Elastic protrusion.

Claims (1)

[Scope of utility model registration request] A taper portion 7 with a wide hole end is formed near the hole opening 5 on one side of the grout hole 2 provided in the concrete construction member, and the taper portion 7 is in close surface contact with the surface of the taper portion 7 to form the above-mentioned portion. A metal temporary frame 8 having a circumferential surface that closes the grout hole 2 is fitted, and a plurality of elastic protrusions 8a are provided on the bottom back side of the temporary frame 8 so as to be in contact with the inner circumferential surface of the grout hole 2. Each is formed protrudingly toward the
A grout hole structure with a muddy water backflow prevention plug is characterized in that the tip of the elastic protrusion 8a is bent inward.