JPH0444720Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field of the Invention) The present invention relates to, for example, a device for fixing lock bolts in the Natom construction method and preventing hardening material from flowing out.

(Conventional Examples and Their Disadvantages) One of the conventional tunnel excavation methods is the Natom method. This construction method involves drilling a tunnel cross-section into the ground, then drilling a large number of holes radially from inside the tunnel.
A lock bolt is fixed in this hole with cement mortar, etc., and this lock bolt supports the ground around the tunnel.

By the way, in the above construction method, the holes are drilled radially, and there was a drawback that the cement mortar etc. would drip down, especially when cement mortar etc. was injected into the upwardly drilled hole and a lock bolt was inserted. Additionally, conventionally, the hole openings were covered with cloth to prevent cement mortar from dripping.
The drawback was that the work was very tedious.

In order to eliminate the above-mentioned drawbacks, for example,
Publication No. 57-77799 proposes a method for preventing the fixing mortar from leaking out of lock bolts for Natom.

However, the stopper disclosed herein has a plurality of curved plate springs provided in grooves provided in a plate-shaped object, and
It has a special configuration in which the plate spring is rolled up and inserted into the hole so that it is located on the inner surface, and has many problems in terms of ease of assembly and ease of insertion into the hole.

(Structure of the present invention) The present invention was made in order to eliminate the drawbacks of the above-mentioned specially structured plug. The main body is press-fitted into the provided hole, and includes a lock bolt having a plurality of tongue pieces separated by making cuts in the lid part, an insertion part through which a nozzle of a mortar injection machine, etc. is inserted, and an air bleed part. A protrusion located on the outer periphery of the main body is integrally provided.

(Effect of the invention) Because of the above configuration, the fixing and outflow prevention device is
When the main body is press-fitted into the hole, the surrounding protrusions are pressed against the hole wall and fixed. Nozzles of mortar injection machines, etc.
Insert into the hole through the insertion part and inject mortar etc. In this case, the presence of the air bleed portion allows the mortar or the like to be completely filled in a predetermined amount. Also,
Even if the nozzle is pulled out, the presence of the tongue prevents the poured mortar etc. from dripping. And after that,
Immediately insert the lock bolt, and the inserted lock bolt can be held in place by the elasticity and frictional force based on the deformation of the tongue. can be prevented from flowing out from the holes.

(Embodiment of the invention) Next, the invention will be explained with reference to drawings which are an embodiment of the invention.

The spill prevention device 1 according to the present invention is made entirely of an elastic material such as rubber, and has a main body 2 having a flange 3 at the rear end, and an insertion portion 6 having a plurality of tongue pieces 9.
and a protrusion 5 located on the outer periphery are integrally provided.

That is, the main body 2 has a cylindrical shape with an insertion portion 6 inside, and the flange 3 and the outer surface of the cylindrical portion are connected by a tapered surface 4 having a protrusion 5 on the surface. Further, a lid part 7 is integrally molded at the tip of the cylindrical body, and a cross-shaped slit 8, for example, is formed in this lid part, and four tongue pieces 9 are formed.

Next, a method of fixing the lock bolt and using the hardening material outflow prevention device constructed as described above will be explained.

First, holes 1 are drilled radially from the inner surface of the tunnel.
The preventer main body 2 is press-fitted into the opening 3 by utilizing its elasticity so that the flange 3 comes into pressure contact with the earth 12. As a result, the surrounding protrusions 5 are pressed against the wall surface of the hole 13, and the main body 2 is prevented from coming off.

Next, the nozzle 14 of the mortar injector is pressed from the insertion part 6 to deform the tongue piece 9 and insert it, positioning the tip at a predetermined position in the hole 13, and injecting a pre-calculated predetermined amount of mortar. In this case, the air etc. that blow out from the hole as the mortar is injected flows out from the gap 10 (constituting the air bleed part) created based on the deformation of the nozzle and the tongue piece, thereby ensuring that a predetermined amount of mortar 16 is poured into the hole. It can be injected inside. Moreover, since the gap 10 is substantially extremely small, mortar will hardly drip down unless pressure is applied (see FIGS. 3 and 4).

When mortar injection is completed, the nozzle 14 is pulled out and a lock bolt 15 is inserted into the hole 13 in place of the nozzle. In this case, when the nozzle 14 is pulled out, the tongue piece 9 returns to its original state, that is, closes the insertion hole 6, and the mortar 16 does not drip down. Further, when the lock bolt 15 is inserted, the excess mortar 16 flows out from the gap 10 due to the insertion pressure of the lock bolt 15, and is completely bonded in the hole, and the lock bolt 15 prevents the tongue piece 9 from deforming. It is held securely in place by its underlying elasticity and its frictional force.

In the above description, a gap 10 created by the deformation of the tongue piece 9 was used without providing a special air release part, but in addition to this, a through groove 11 may be provided in the inner wall of the insertion hole 6.

Further, in the above embodiment, the present invention is applied to the natom construction method, but the present invention is not limited to this, and it goes without saying that the present invention can be applied as long as the lock bolt is fixed in the hole with mortar or the like.

[Brief explanation of the drawing]

1 and 2 show the main body of the lock bolt fixing and hardening material outflow prevention device according to the present invention, FIG. 1 is a front view, FIG. 2 is a plan view, and FIG. 3 is a line taken along the line - 4 is a front view showing the state of deformation of the tongue when the nozzle (or lock bolt) is inserted into the main body; FIG. 5 is a plan view of FIG. 4; and FIG. It is an explanatory view showing the use state of a material outflow prevention tool. 2...Main body, 3...Flange, 5...Protrusion, 6
...Insertion part, 7...Lid part, 8...Slit, 9...
... tongue piece, 10 ... gap, 11 ... penetration groove, 12 ...
...ground, 13...hole, 14...injector nozzle, 1
5...Rock Bolt.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A hardening material such as mortar is injected into a hole made in the ground, etc., and a hardening material outflow prevention device used when installing a lock bolt into the hole is press-fitted into the hole. A main body made of an elastic material to be attached, a lock bolt having a plurality of tongue pieces separated by making cuts in the lid, an insertion part for a nozzle of a mortar injection machine, etc.
A device for fixing a lock bolt and preventing hardening material from flowing out, characterized in that an air bleed part located at the insertion part and a protrusion located at the outer periphery of the main body are integrally provided. (2) The device for fixing a lock bolt and preventing hardening material from flowing out as set forth in claim 1, wherein the air bleed portion is a through groove provided along the inner wall of the insertion portion.