JP6994716B2 - Anchor construction method - Google Patents

Description

The present invention relates to an anchor construction method.

Conventionally, in order to improve the pulling force of post-installed anchors, expansion type metal anchors such as internal cone driving type, sleeve type, wedge type, etc. or capsule type or cartridge type chemical anchors are generally used. With the conventional method, there is a possibility that it will easily fall off when gravity is applied vertically downward as in the case of the collapse of the ceiling plate of the Sasako tunnel on the Chuo Expressway on December 2, 2012 and the example of the expressway in Boston, USA. It can be said that there is a self-evident reason.

On the other hand, although L-shaped deformed steel bars are embedded before concrete is placed, most of the post-installed anchors are straight all-screw bolts or metal anchors, and the L-shaped anchors are bent. A major challenge remains regarding the insertion of bolted steel bars. Specifically, in general, when drilling a structure to be constructed, only a substantially circular vertical hole can be generally formed. If the L-shaped anchor can be installed later, the possibility of the L-shaped anchor falling off easily can be suppressed to a very low level.

Therefore, in view of the above problems, it is an object of the present invention to provide an anchor construction method to which a bent steel bar such as an L-shaped or V-shaped anchor can be applied.

As a result of diligent studies on the above problems, the present inventor has formed a plurality of vertical holes, and by expanding the vertical holes, even a bent steel bar can be inserted and stably filled. This led to the completion of the present invention.

That is, the anchor construction method according to one aspect of the present invention includes a step of forming a plurality of substantially circular vertical holes adjacent to each other, a step of expanding a plurality of vertical holes to form an elliptical vertical hole, and an elliptical vertical hole. It also includes a step of inserting an L-shaped anchor and a step of pouring epoxy resin or non-shrink mortar into an elliptical vertical hole to fill the hole.

Further, from this viewpoint, although not limited, the step of expanding a plurality of vertical holes to form an elliptical vertical hole is a hole following the step of cutting in a region connecting adjacent vertical holes with a straight line. The side wall and the bottom of the mortar may be cut with a cutter or a bull point to provide a recess, and the epoxy resin or non-shrink mortar that has been filled in the hole later may be provided with a step of entering the recess and making it difficult to pull out. preferable.

As described above, the present invention provides an anchor construction method to which a bent steel bar such as a V-shaped anchor can be applied in addition to the L-shaped anchor.

It is a figure which shows the outline of the process of the anchor construction method which concerns on embodiment. It is a figure which shows the example about the arrangement of a plurality of vertical holes. It is a figure which shows the example which expanded a plurality of vertical holes. It is a figure which shows the example which expanded the side surface and the bottom. It is a figure which shows the example of the anchor reinforced by the triangular reinforcing iron plate and the reinforced round bar. It is a figure which shows the example of the anchor reinforced by the perforated reinforcing iron plate.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention can be implemented in many different embodiments, and is not limited to the specific examples in the embodiments and examples shown below.

The anchor construction method according to the present embodiment (hereinafter referred to as "this method") includes (1) a step of forming a plurality of substantially circular vertical holes adjacent to each other, and (2) expanding a plurality of vertical holes to form an elliptical shape. It is provided with a step of forming a vertical hole, (3) a step of inserting an L-shaped anchor into the elliptical vertical hole, and (4) a step of pouring epoxy resin or non-shrink mortar into the elliptical vertical hole to fill the hole. FIG. 1 is a diagram showing an outline of the process of this method.

First, this method includes (1) a step of forming a plurality of substantially circular vertical holes adjacent to each other. In general, it is difficult to directly form an elliptical vertical hole. It is not impossible to form it by using a special tool, but it will increase the cost. Therefore, in this method, it is easy to form an elliptical vertical hole by adjoining a plurality of generally substantially circular vertical holes.

The formation of the substantially circular vertical hole is not particularly limited, and a known vertical hole forming method can be adopted. For example, a drill for excavation can be used, and this drill can be pressed against a structure to be constructed (for example, a concrete floor, ceiling, wall surface, etc.) to form a vertical hole. The diameter of the vertical hole is not particularly limited and can be appropriately adjusted according to the diameter of the steel bar to be inserted.

Further, the number of vertical holes is not particularly limited, and it can be appropriately formed depending on the shape of the holes to be formed. An example of this case is shown in FIG. 2, for example. In the example of this figure, for example, a general elliptical shape (A) and a T-shaped shape (B) in which elliptical shapes are combined are shown, but the present invention is not limited to this.

Further, in this step, the depths of the plurality of vertical holes can be appropriately adjusted and are not limited. It is preferable to make the depths of the plurality of vertical holes uniform from the viewpoint of stable arrangement of the steel bars, but they may be different.

Further, this method includes (3) a step of inserting an L-shaped anchor into an elliptical vertical hole as described above. The elliptical shape in this way makes it possible to insert an L-shaped or V-shaped anchor or the like.

Further, this method includes (2) a step of expanding a plurality of vertical holes to form an elliptical vertical hole as described above. An image diagram in this case is shown in FIG. This figure is an extension of each of the vertical holes in FIG.

Further, the tool used for expanding the side wall and the bottom portion is not limited as long as it can be excavated, and for example, a cutter, a bull point, or the like can be used.

Further, in this step, it is also preferable to include a step of expanding the vicinity of the bottom of the vertical hole. It is also possible to cut a part of the side surface or the bottom surface of the vertical hole with a cutter or a bull point to provide a recess, and the anchor can be more firmly fixed. An image diagram in this case is shown in FIG.

In this step, the number of anchors to be inserted can be adjusted as appropriate and is not limited. For example, in the case of the hole shown in FIG. 3B, two or more anchors can be inserted.

Further, this method includes (4) a step of pouring an epoxy resin or non-shrink mortar into an elliptical vertical hole to fill the hole.

Known epoxy resins and non-shrink mortars can be used in this step, but in the case of epoxy resin, for example, the main agent and the curing agent two liquids are sufficiently stirred and mixed outside the holes using a stirrer or a spatula. Then, after confirming that there is no mixing defect, the injection process can be started. The main agent and curing agent are pre-colored in pale red and pale blue, and when mixed, they become complementary colors and become white. In addition, by adding a chixo agent, it is possible to give the property that it does not drip even when hit with a caulking gun toward the ceiling. If necessary, the type and amount of curing agent can be adjusted to freely adjust the curing.

The well-mixed adhesive thus prepared is packed in a polyolefin cartridge, attached to an inexpensive caulking gun, and injected into the expanded bottom using a long nozzle. At the time of injection, it is preferable to be careful not to allow air to enter.

Thus, after the epoxy resin is cured, the bottom-expanded portion, the anchor portion, and the entire hole portion are integrated by the resin and are firmly adhered to the wall surface of the vertical hole, so that they cannot be easily pulled out.

In this case, it is preferable that the amount of the adhesive fills the gaps between the holes and the excess amount slightly protrudes from the hole entrance.

By the way, for L-shaped anchors or V-shaped anchors, iron plates are welded to the bent parts to reinforce them, and if necessary, iron bars or strip-shaped iron plates are welded to them to fill them with epoxy resin or nothing. The shrinkage mortar can be reinforced. An image of this anchor is shown in FIG. 5, and another example is shown in FIG. By doing so, it is possible to prevent the bending angle from becoming large when the L-shaped anchor or the V-shaped anchor is pulled, and by welding the iron bar or strip-shaped iron plate, epoxy resin or non-shrink mortar can be used. It becomes possible to entangle with, and it becomes possible to fix it more firmly. Specifically, this reinforced anchor is a step of welding an iron plate to the bent part of an L-shaped or V-shaped anchor to reinforce it, and anchoring an iron bar or strip-shaped iron plate to reinforce the epoxy resin or non-shrink mortar to be filled later. Can be manufactured by welding steps.

As described above, this method is an anchor construction method to which a bent steel bar such as an L-shaped anchor or a V-shaped anchor can be applied.

Here, the anchor construction method based on the above embodiment was actually confirmed. This will be described in detail below.

(Example 1)
First, a hammer drill (Hitachi DH40MR) was used to form concrete with two holes having a drill bit of 26 mmφ and a depth of 120 mm so that these holes would be in contact with each other as shown in FIG.

Next, using a cutter, the vicinity of the connecting portion of these two holes was cut to form an elliptical vertical hole while forming a side portion and a bottom portion. Further, further drilling was performed at a bull point in the bottom corner portion of this elliptical vertical hole to form a recess having a shape as shown in FIG.

Next, as an L-shaped anchor, a deformed steel bar (JIS G3112 SD345) D19 (diameter 19.1 mmφ) is inserted into the elliptical vertical hole, and an epoxy resin adhesive (Unique, Inc., "Uniepo") is used to apply this resin. It was filled between the vertical hole and the L-shaped anchor and cured. Specifically, the main agent and the curing agent were placed in an equal amount container, stirred and mixed using a stirrer until uniform, and about 400 g was filled between the elliptical vertical hole and the L-shaped anchor.

Then, it was allowed to stand at room temperature for one week, and after being sufficiently cured, a tensile test was performed. As a result, it was possible to confirm a high strength of 65 kN.

(Example 2)
In this embodiment, it is almost the same as that in the first embodiment, but only the shape of the L-shaped anchor is different. Specifically, as shown in FIG. 5, a triangular iron plate having a thickness of 6 mm and a side of 30 mm is welded to the L-shaped portion of the L-shaped anchor, and an iron rod for reinforcement having a diameter of 6 mm is further welded to this iron plate. Was done by welding.

Then, in the same manner as above, when a tensile test was performed, the deformed steel bar broke at the threaded portion (corresponding to M16), and a higher strength of 107 kN could be confirmed.

That is, the effectiveness of this method could be confirmed by these examples.

The present invention has industrial applicability as an anchor construction method.

Claims (2)

A step of forming multiple circular vertical holes adjacent to each other in a concrete construction target structure ,
A step of expanding a plurality of the vertical holes to form an elliptical vertical hole,
A step of cutting the side surface and bottom surface of the vertical hole with a cutter or bull point to provide a recess.
A step of inserting an L-shaped or V-shaped anchor into the elliptical vertical hole,
An anchor construction method comprising a step of pouring an epoxy resin or a non-shrink mortar into the elliptical vertical hole to fill the hole so that the epoxy resin or the non-shrink mortar enters the recess and is difficult to pull out . A step of welding an iron plate to the bent part of an L-shaped or V-shaped anchor to reinforce it so as to prevent the bending angle from becoming large .
The anchor construction method according to claim 1, further comprising a step of welding an iron bar or a strip-shaped iron plate to an anchor to reinforce an epoxy resin or non-shrink mortar to be filled later.

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