JPS6262208B2 - - 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 attached to the driving head. Alternatively, the anchor rod is inserted into a pre-drilled hole for cutting, etc., and then the surrounding soil layer is excavated using the locking piece that is expanded by rotating the anchor rod body, and then mortar, concrete or synthetic resin is inserted into the hole. Anchor rods having pull-out resistance were constructed by injecting the same into the anchor rod body to form a lump at the tip of the anchor rod body.

(Problem 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.
Alternatively, other construction equipment such as means for rotating the anchor rod body was required, and moreover, it required some ingenuity to dispose of the soil produced by re-excavation. 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
In particular, when constructing retaining walls several meters in height or more than 10 meters in height, the number of days and costs required for construction is enormous, and the construction is difficult in areas with a high concentration of people and facilities. was.

Furthermore, conventional anchor rods have the disadvantage that the lumpy body at their tip tends to be eccentric with respect to the shaft center, so variations in their performance can be caused by
This had a negative impact on the stability of constructed retaining walls.

(Object of the Invention) The present invention has been made in order to improve the above-mentioned conventional drawbacks and solve 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) In other words, the anchor rod of the present invention has a generally U-shaped cut in the peripheral wall of the anchor rod body made of a cylindrical body, the base of which is directed toward the tip of the anchor rod body, and the base of which is directed toward the rear end of the anchor rod body. At least one substantially U-shaped cut facing toward the anchor rod body is provided, and a closing fitting is attached to the tip opening of the anchor rod body, so that an expansion agent can be injected and accommodated from the rear end opening of the anchor rod body. It is characterized by

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

FIG. 1 is an exploded perspective view showing one embodiment of the present invention, and reference numeral 1 in the figure indicates an anchor rod body made of a cylindrical body made of metal or synthetic resin;
The peripheral wall has a U-shaped cut 2 with the base facing the tip of the anchor rod body 1 and a U-shaped cut 3 with the base facing the rear end of the anchor rod body 1 along the longitudinal direction of the anchor rod body 1. A plurality of them are provided approximately on the same line. These cuts 2..., 3... form U-shaped tongue pieces 4..., 5.... Reference numeral 6 in the figure is a closing fitting, and its rear end 6b is the tip opening 1 of the anchor rod body.
It is press-fitted into a. This prevents soil from entering the anchor rod body 1 in the ground, and forms an expansion agent storage chamber into which the expansion agent can be injected and stored through the rear end opening 1b of the anchor rod body 1. This closing fitting 6 is used for driving, and its tip 6a has a sharp shape. in this way,
The anchor rod A is composed of an anchor rod body 1 and a closing fitting 6.

As described above, in the above embodiment, the U-shaped cuts 2..., 3 are formed on the peripheral wall of the anchor rod main body 1.
... and simply attaching the closing fitting 6 to the tip opening 1a, it is extremely easy to manufacture and therefore inexpensive. After pouring or burying on site, the rear end opening 1 of the anchor rod body 1 is
If the expansion agent is injected from b, the expansion pressure will cause
As the U-shaped tongues 4..., 5... stand up, the anchor rod body 1 around them expands, so that the pull-out resistance and support in the ground are significantly increased. In addition, as will be explained in detail below, cuts 2..., 3... are made in the peripheral wall of the anchor rod body 1 at the factory, and it is only necessary to cast them on site. Since it is only necessary to drill holes with approximately the same diameter, construction of retaining walls and the like can be carried out quickly and economically.

In the above embodiment, the anchor rod body 1 is made of a cylindrical body, but a hollow prismatic body may also be adopted. The shapes of the cuts 2..., 3... are also U-shaped, but in the present invention, they are not limited to a strict U-shape, but may be approximately U-shaped, such as a square, square, semicircular, U-shape, or V-shape. The shape of the anchor rod does not matter as long as it faces the tip or rear end of the anchor rod body. Furthermore, although the cuts 2..., 3... are provided on approximately the same line along the longitudinal direction of the anchor rod main body 1, this does not necessarily have to be the case. They may be provided alternately on the same line. The number of cuts 2..., 3... is preferably as large as possible as long as it does not significantly affect the strength of the anchor rod body 1, but it is preferable to provide them as close to the tip of the anchor rod body 1 as possible, and at least one cut each or in the same circle on the peripheral wall. It is sufficient to provide a total of three locations on the circumference.

Further, in the above embodiment, the anchor rod main body 1 and the closing fitting 6 are separate members, but they may be formed integrally, or the tip opening 1a of the anchor rod main body 1 and the rear end portion 6b of the closing fitting 6 may be formed integrally. It is also possible to have male and female screws. For embedding, a closing metal fitting with a flat tip as shown in FIG. 3 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. 4, a plurality of anchor rods A of the above embodiment are inserted into the embankment 9 through holes 8 drilled at predetermined intervals in the retaining wall 7 at an acute angle to the vertical axis of the retaining wall. Drive to the desired depth. It is preferable to use anchor rods A that are relatively short when driven into the upper part of the retaining wall 7, and gradually become longer as they reach the lower part. However, the method is not necessarily limited to this, and long anchor rods and short anchor rods may be driven alternately.
Furthermore, if the ground is soft, it is preferable to use a long anchor rod.

Each anchor rod A driven in this way...
The swelling agent 10 is passed through the rear end opening 1b through the cuts 2..., 3.
Inject to the position where... is provided. The swelling agent 10 is a mixture of an inorganic compound mainly composed of silicate, a specific organic compound, and water. For example, a mixture of BLISTER (trade name) manufactured by Onoda Cement Co., Ltd. and water can be suitably used.

The injected swelling agent 10 hardens and expands, and reaches its maximum inflation pressure after about 12 to 24 hours. As shown in FIG. 5, this inflation pressure causes the U-shaped tongues 4..., 5
... stand up, and the tongues 5 provide pull-out resistance to the anchor rod A, and the tongues 4 provide support. The pull-out resistance of the anchor rod A increases the stability of the front surface of the retaining wall 7, and the supportability of the anchor rod A increases the stability of the rear surface of the retaining wall 7. As a result, the stability of the retaining wall 7 becomes extremely good. Fig. 6 is a partial perspective view of the anchor rod main body 1 showing a state in which the tongue pieces 4..., 5... are erected, and Fig. 7 is a partial perspective view of the anchor rod main body 1 showing a state in which the tongue pieces 4..., 5... are erected.
It is a sectional view taken along the Y line. Together with the erection of the tongue pieces 4..., 5..., the cut 2... of the cylindrical body 1 of the anchor rod A...,
3... By enlarging the surrounding area (enlarged portion 11...), compressive stress is applied to the surrounding soil layer, resulting in consolidation. As a result, anchor rod A... and embankment 9
A large frictional force occurs between them.

After the expansion of the expansion agent 10 is completed, a closing fitting is attached to the upper end opening of each anchor rod A projecting from the retaining wall 7, and tension is applied to each anchor rod A using a tightening means such as a nut. By applying tension in this manner, the tongues 5 are further erected due to the resistance of the embankment 9, while the tongues 4 are slightly returned, thereby causing the anchor rods A...
The pull-out resistance and supporting capacity of will be 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, since it is only necessary to make cuts 2..., 3... in the peripheral wall of the anchor rod body 1 at the factory and then cast or bury it on site, there is no need for many construction machines, and therefore the movement of construction machines on site is easy. It becomes easier. As a result, even if the temporary scaffolding is simple, there will be no inconvenience during construction, and construction efficiency will be extremely high. Therefore, the number of on-site workers is reduced, making it possible to save labor, and construction can be carried out easily and quickly even in areas where houses and facilities are crowded.

(Effects of the Invention) As explained 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 support in the ground. 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 partial perspective view showing one embodiment of the present invention, FIG. 2 is a sectional view taken along the line X--X of FIG. 1, FIG. 3 is a perspective view showing another embodiment of the closure fitting, and FIG. The figure is a cross-sectional view showing the above-mentioned embodiment driven into the embankment through a hole provided in the retaining wall, and Figure 5 shows the above-mentioned embodiment formed by the expansion pressure of the expansion agent in the embankment. FIG. 6 is a cross-sectional view showing a state in which the tongue piece is erected and its surrounding area is enlarged; FIG. 6 is a sectional view taken along the line Y--Y in FIG. 6, with the expansion agent omitted. A... Anchor rod, 1... Anchor rod body, 2, 3... Cut, 4, 5... Tongue piece, 6...
Closure fitting, 7... Retaining wall, 9... Embankment, 10... Expansion agent, 11... Ampulla.

Claims (1)

[Claims] 1. A substantially U-shaped cut with the base facing the tip of the anchor rod body and a substantially U-shaped cut with the base facing the rear end of the anchor rod body on the peripheral wall of the anchor rod body consisting of a cylindrical body. At least one of each is provided, and a closing fitting is attached to the tip opening of the anchor rod body,
An anchor rod characterized in that it is constructed such that an expansion agent can be injected and accommodated from the rear end opening of the anchor rod main body.