JPS6337207B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an anchor rod used in construction or civil engineering work. In particular, the present invention relates to anchor rods used for constructing or reinforcing retaining walls to prevent the collapse of steps of various sizes formed on land, such as cliffs, embankments, or river embankments.

(Prior Art) An anchor rod of this type has been provided with an enlarged tip in order to provide resistance to being pulled out from the ground. These anchor rods are usually manufactured at the construction site. For example, an anchor rod body consisting of a steel rod or steel pipe, which has a driving head fixed at its tip and a plurality of locking pieces that can be opened and closed by rotation and can be opened and closed, is fixed to the driving head. Or, after excavating the soil layer around the anchor rod by inserting it into a pre-drilled hole in cutting, etc., and then rotating the anchor rod body and expanding it,
An anchor rod having pull-out resistance was constructed by injecting mortar, concrete, synthetic resin, etc. into the drilled hole to form a lump at the tip of the anchor rod body.

(Problems to be Solved by the Invention) However, the conventional anchor rod manufactured in this manner has a drawback in that the lump at the tip tends to be eccentric with respect to its axis.

In addition, in order to form a lump at the tip, a hole with a larger diameter than the pre-drilled hole must be made at the tip, so two types of excavators are required, or other means such as rotating the anchor rod body are required. Construction machinery was required, and moreover, the disposal of the soil created by re-excavation required ingenuity. As a result, conventional anchor rods have become expensive.

Furthermore, these problems in manufacturing conventional anchor rods place significant restrictions on integral construction, such as construction of retaining walls.
That is, in order to manufacture conventional anchor rods, it is necessary to drill holes with a relatively large diameter, making it difficult to construct retaining walls on soft embankments or cuttings. In addition, not only a large excavator but also other machines such as means for rotating the anchor rod are required, so moving these construction machines not only impairs work efficiency but also requires a relatively large construction area. This means that, especially when constructing retaining walls several meters or more than 10 meters in height, not only will the construction time and cost be enormous, but it will also be difficult to construct in areas where there are a lot of people and facilities. was posing a problem.

(Object of the Invention) The present invention has been made in order to improve the above-mentioned conventional drawbacks and eliminate the above-mentioned problems. The purpose of the present invention is to provide an extremely high-quality anchor rod, and furthermore, to provide an anchor rod that allows construction of retaining walls and the like to be carried out quickly and economically.

(Structure of the Invention) That is, the anchor rod of the present invention has an approximately U-shaped cut with the base facing toward the tip of the anchor rod body, and a substantially U-shaped cut with the base facing the tip of the anchor rod body, on the peripheral wall of the outer tube of the anchor rod body consisting of the outer tube and the inner tube. A substantially U-shaped cut facing the rear end of the anchor rod body is provided, and a closing fitting is attached to the opening at the tip of the anchor rod body, so that the anchor rod can be opened from the rear end opening of the anchor rod body between the outer tube and the inner tube. The invention is characterized in that it is configured such that an expansion agent can be injected into the gap formed in the gap.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is an exploded overall perspective view showing one embodiment of the present invention. Reference numeral 1 in the figure is an anchor rod main body, which is composed of an outer tube 2 and an inner tube 3, which are cylindrical bodies made of metal or synthetic resin. A gap 4 having a constant width is formed between the outer tube 2 and the inner tube 3. On the peripheral wall of the outer tube 2 of the anchor rod body 1, there are a U-shaped cut 5 whose base faces toward the rear end of the anchor rod body 1, and a U-shaped cut 6 whose base faces toward the tip of the anchor rod body 1. There are multiple. U-shaped tongue pieces 7, 8, and so on are formed by these cuts 5, 6, and so on. FIG. 2 is a sectional view taken along the line X--X in FIG. 1.
On the other hand, reference numeral 9 in FIG. 1 is a closing metal fitting, the rear end 9c of which is connected to the tip opening 3a of the inner tube 3 of the anchor rod main body 1, and the central portion 9b is connected to the tip opening 2a of the outer tube 2 of the anchor rod main body 1. Press-fitted and fixed. By attaching the closing fitting 9 to the anchor rod body 1, soil is prevented from entering the anchor rod body 1 in the ground, and an expansion agent can be injected into the gap 4 between the outer tube 2 and the inner tube 3. A containment chamber is formed. Note that this closure fitting 9 is for driving, and the tip end 9a has a sharp shape.
In this way, the anchor rod A is constructed from the anchor rod main body 1 and the closing fitting 9.

As explained above, according to the above embodiment, the U-shaped cuts 5, 6, and so on are provided in the peripheral wall of the outer tube 2 of the anchor rod main body 1, and the closing fitting 9 is provided in the tip opening 1a of the anchor rod main body 1. Since it has a simple structure that only requires mounting, it can be manufactured at a factory, etc., and it is extremely easy to manufacture, and therefore, it is inexpensive. After the anchor rod is cast or buried on site, if an expansion agent is injected into the gap 4 between the outer tube 2 and the inner tube 3 from the rear end of the anchor rod main body 1, the expansion pressure will cause the U-shaped cut 7... 8 stands up and the surrounding anchor rod body 1 expands, so that the pull-out resistance and support in the ground are significantly increased. In addition, since the inner tube 3 is inserted, even if the wall thickness of the outer tube 2 is reduced, and even if a large number of U-shaped cuts 5, 6, etc. are provided, the strength of the anchor rod A itself is greatly increased. will not decrease. Therefore, even if the diameter of the anchor rod A itself is reduced, extremely high pull-out resistance can be ensured by increasing the number of cuts 5, 6, etc. It can be advantageously adopted, and even when buried in soft ground, the diameter of the hole to be drilled for burial can be made smaller to maintain the bearing capacity of the ground. In addition, as explained in detail below, the anchor rod body 1 is
Cuts 5......, 6...... are made in the peripheral wall of the outer pipe 2, and it is sufficient to simply cast them at the site.Also, when buried, a hole with a diameter approximately equal to the outer diameter of the outer pipe 2 is drilled. This makes it possible to construct retaining walls quickly and economically.

In the above embodiment, the outer tube 2 and the inner tube 3 of the anchor rod main body 1 are cylindrical bodies, but in the present invention, they may be hollow prisms. Further, in order to increase the strength of the anchor rod itself, cement, mortar, or synthetic resin may be injected into the inner tube 3, and the inner tube 3 may be a cylinder or a square column. Cut 5……, 6……
The shape of ... is not limited to a strict U-shape, but may be, for example, a square shape, a square shape, a semicircular shape, a U-shape, a V-shape, etc., and the base thereof should face the rear end of the anchor rod body 1. However, its shape does not matter.
Furthermore, although the cuts 5, 6, and so on are provided approximately on the same line along the longitudinal direction of the outer tube 2 of the anchor rod main body 1, they do not necessarily have to be in this manner, and the anchor rod main body They may be provided alternately on substantially the same line along the longitudinal direction of one outer tube 2. It is preferable to have a large number of cuts 5..., 6..., and even if a large number of cuts are provided, the strength of the anchor rod itself will not be significantly reduced as it is supported by the inner tube 3. Even if it is provided in several places, a sufficient effect can be achieved. Further, in the above embodiment, the cuts 5, 6, etc. are provided only on the peripheral wall of the outer tube 2 of the anchor rod main body 1, but they may also be provided on the peripheral wall of the inner tube 3. In this case, if a substantially U-shaped or substantially linear cut is provided at a position corresponding to the cut in the outer tube 2, and an inflating agent is also injected into the inner tube 3, the tongue piece formed in the inner tube 3 can stand up or the cut can be made. Due to the expansion of the peripheral portion, the tongues formed on the outer tube 2 stand up even more, and as a result, the pull-out resistance and support of the anchor rod in the ground become extremely large.

Further, in the above embodiment, the anchor rod main body 1 and the closing fitting 9 are separate members, but in the present invention, they may be formed integrally, or the tip opening of the inner tube 3 and the closing fitting 9 The end portion 9c or the tip opening of the outer tube 2 and the center portion of the closure fitting 9 may be male and female screwed together. Furthermore, as shown in Figure 3,
A fitting hole 9d is provided in the rear end 9c of the closure fitting 9,
The tip of the inner tube 3 of the anchor rod body 1 may be press-fitted and fixed. For embedding, a closing metal fitting 9 with a flat tip as shown in FIG. 4 may be used.

Hereinafter, the functions and effects of the anchor rod of the present invention will be explained in more detail by explaining an example of a retaining wall reinforcement method that can be carried out by employing the anchor rod A of the above embodiment.

First, as shown in FIG. Drive to the desired depth.
It is preferable that the anchor rod A is relatively short when driven into the upper part of the retaining wall 10, and becomes gradually longer towards the lower part. However, the method is not necessarily limited to this, and long anchor rods and short anchor rods may be driven alternately. Further, it is preferable to use a long anchor rod A when the ground is soft.

Each anchor rod A driven in this way...
The swelling agent 13 is injected into the gap 4 between the outer tube 2 and the inner tube 3 from the rear end opening 1b to the position where the cuts 5, 6, and so on are provided. This swelling agent 13
is a mixture of inorganic compounds mainly composed of silicates, specific organic compounds, and water. For example, a mixture of BLISTER (trade name) manufactured by Onoda Cement Co., Ltd. and water can be suitably used. Note that a mixture of this expanding agent 13 with a small amount of cement, mortar, etc. may also be used.

The injected swelling agent 13 hardens and expands, and reaches its maximum inflation pressure after about 12 to 24 hours, and as shown in FIG. 6, this inflation pressure causes the U-shaped tongue piece 7...
8... stands up and attaches tongue 7 to anchor rod A.
. . . provides pull-out resistance, and the tongue pieces 8 . . . provide support. The pull-out resistance of the anchor rods A increases the stability of the front surface of the retaining wall 10, and the support of the anchor rods A increases the stability of the retaining wall 10.
The stability of the rear surface of 0 is increased. As a result, retaining wall 1
The stability of 0 is extremely good. Figure 7 shows tongue piece 7.
. . , 8 is a partial perspective view of the anchor rod main body 1 showing a state in which it stands up, and FIG. 8 is a sectional view taken along the Y-Y line in FIG. 7 with the expansion agent omitted. Together with the rising of the tongue pieces 7..., 8......, cuts 5......, 6 in the outer tube 2 of the anchor rod body 1
As the surrounding area expands (enlarged portion 14...), compressive stress is applied to the surrounding soil layer, resulting in consolidation. As a result, anchor rod A...
A large frictional force is generated between the anchor rod A and the embankment 12, and the pull-out resistance and support of the anchor rod A are further increased.

After the expansion of the expansion agent 13 is completed, a closing fitting is attached to the upper end opening of each anchor rod A protruding from the retaining wall 10, and tension is applied to each anchor rod A using a tightening means such as a nut. By applying tension in this way, the tongue pieces 7...... are further erected due to the resistance of the embankment 10,
On the other hand, the tongue piece 8 returns slightly and the pull-out resistance and support of the anchor rod A become even greater.

As described above, the reinforcement of the retaining wall employing the above embodiment of the anchor rod of the present invention is completed. Incidentally, if the upper end of each anchor rod A is not preferably exposed from the retaining wall, a surface layer may be coated thereon.

As mentioned above, even when reinforcing a retaining wall, the pull-out resistance and supportability of the anchor rod A of the above embodiment are extremely high, so even if relatively short and small rods are used, sufficient effects can be achieved, and the arrangement of the anchor rods It is also possible to reduce the number of devices. In addition, good stability can be imparted to a thin retaining wall such as a concrete layer constructed using a spray construction method, or to a retaining wall with a height of 10 m or more. Furthermore, it is only necessary to make cuts 5, 6, etc. in the peripheral wall of the anchor rod body 1 at the factory and then cast or bury it at the site, which eliminates the need for many construction machines. It becomes easier to move. Therefore, even if the temporary scaffolding is simple, there will be no inconvenience during construction, and construction efficiency will be extremely high. As a result, the number of workers on site is reduced, making it possible to save labor, and construction can be carried out easily and quickly even in densely populated areas with people's homes and facilities.

(Effects of the Invention) As detailed above, according to the present invention, it is possible to provide an anchor rod that is extremely easy to manufacture and has extremely high pull-out resistance and supportability in the ground, and can be used for retaining walls, etc. It is possible to provide an anchor rod that can be constructed quickly and economically.

[Brief explanation of the drawing]

Fig. 1 is an exploded overall perspective view showing one embodiment of the present invention, Fig. 2 is a sectional view taken along the line X-X of Fig. 1, and Figs. 3 and 4 each show other embodiments of the closure fitting. A perspective view, FIG. 5 is a sectional view showing the above embodiment driven into embankment through a hole provided in a retaining wall, and FIG. FIG. 7 is a cross-sectional view showing a state in which the tongue piece formed in the above is erected and its surrounding area is enlarged; FIG. FIG. 8 is a sectional view taken along the line Y--Y in FIG. 7, with the expansion agent omitted. A... Anchor rod, 1... Anchor rod body, 2... Outer tube, 3... Inner tube, 4... Gap,
5, 6... cut, 7, 8... tongue piece, 9... closing metal fitting, 10... retaining wall, 12... embankment, 13... swelling agent, 14... ampulla.

Claims (1)

[Claims] 1. On the peripheral wall of the outer tube of the anchor rod body consisting of an outer tube and an inner tube, there is a roughly U-shaped cut with the base facing the tip of the anchor rod body, and a roughly U-shaped cut with the base facing the rear end of the anchor rod body. At the same time, a closing fitting is attached to the opening at the tip of the anchor rod body, and an expansion agent is injected and accommodated from the opening at the rear end of the anchor rod body into the gap formed between the outer tube and the inner tube. An anchor rod characterized by being configured so as to be able to do so.