JPH023847B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an anchor rod used in civil engineering works such as construction and reinforcement of buildings or retaining walls.

(Prior Art) Anchor rods have been provided that have enlarged tips in order to provide resistance to pulling 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 a steel pipe, on which a driving head is fixed at the 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 ground. The anchor rod is inserted into a pre-drilled hole, and the surrounding soil layer is excavated using the locking piece, which is expanded by rotating the anchor rod body, and then mortar, concrete, or synthetic resin is injected into the hole. By forming a lump at the tip of the anchor rod body,
It constituted an anchor rod with pull-out resistance.

(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.
Alternatively, other construction machinery 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 underground where the ground is soft. 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 makes the work harder, but also requires a relatively large construction area. This not only increases the number of days and costs required for construction, but also poses the problem that construction is difficult in areas where houses and facilities are densely populated.

The present invention has been made in order to improve the above-mentioned conventional drawbacks and eliminate the above-mentioned problems.It is an object of the present invention to provide an anchor rod that can be manufactured extremely easily and has extremely high resistance to underground extraction. To provide an anchor rod that enables construction of retaining walls and the like to be carried out quickly and economically.

(Means for Solving the Problems) The anchor rod of the present invention has a plurality of cuts that form a substantially inverted U-shape when the outer tube is stood upright on the peripheral wall of the outer tube of the anchor rod main body consisting of an outer tube and an inner tube. and a plurality of cuts that are approximately vertically straight are provided,
A closure fitting is attached to the tip opening of the anchor rod body, and an expansion agent can be injected and filled into the gap formed between the outer tube and the inner tube from the anchor rod body and the rear end opening. This is what I did.

(Function) An expansion agent is injected and filled into the gap between the outer tube and the inner tube constituting the anchor rod body, thereby forming an enlarged portion and an upwardly opening tongue piece in the anchor rod body that increases the pulling resistance.

(Example) Examples of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an exploded overall perspective view showing one embodiment of the present invention. In the figure, reference numeral 1 denotes the anchor rod body, which consists of an outer tube 2 and an inner tube 3, which are cylindrical bodies made of metal or synthetic resin. A small-diameter inner tube 3 is inserted into a large-diameter outer tube 2. A gap 4 having a constant width is formed between the outer tube 2 and the inner tube 3. Outer tube 2
A plurality of cuts 5 which form a substantially inverted U-shape when the outer tube 2 is stood upright, and a plurality of cuts 6 which form a substantially linear shape are provided in the peripheral wall portion of the outer tube 2 . Cut 5...
As a result, a plurality of tongue pieces 7 that open upward are formed. Figures 2 and 3 are W- of Figure 1, respectively.
It is a cross-sectional view taken along the W line and the X-X line.

On the other hand, 8 in FIG. 1 is a closing fitting, and the rear end 8
c is press-fitted and fixed into the tip opening 3a of the inner tube 3 of the anchor rod main body 1, and the central portion 8b is press-fitted into the tip opening 2a of the outer tube 2 of the anchor rod main body 1. By attaching the closing fitting 8 to the anchor rod body 1, it is possible to prevent soil from entering the anchor rod body 1 underground, and also to inject and fill the gap 4 between the outer pipe 2 and the inner pipe 3 with an expanding agent. A containment chamber is formed. Note that the attachment of the closing fitting 8 to the tip opening 1a of the anchor rod main body 1 is not limited to that shown here. The closing fitting 8 is mainly used for pouring, and the distal end portion 8a has a sharp shape. In this way, the anchor rod A is composed of the anchor rod main body 1 and the closing fitting 8.

As explained above, according to the above embodiment, the peripheral wall of the distal end of the outer tube 2 of the anchor rod main body 1 has a plurality of cuts 5, which form a substantially inverted U-shape when the outer tube 2 is stood upright, and a plurality of cuts. Cut 6 that is approximately vertically straight...
and a tip opening 1 of the anchor rod body 1.
Since it has a simple structure of just attaching the closing fitting 8 to a, it can be manufactured in a factory or the like, and it is extremely easy to manufacture and therefore inexpensive. After casting or burying the anchor rod at the 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 opening 1b of the anchor rod main body 1, the expansion pressure causes the tongue to open upward. As the pieces 7 stand up, the anchor rod body 1 around them expands. In addition, as the cracks in the linear cuts 6 expand, the anchor rod body 1 around them expands, and the resistance to pulling out underground increases significantly. Inner tube 3
is inserted, so even if the wall thickness of the outer tube 2 is made small or a large number of cuts 5..., 6... are provided,
The strength of anchor rod A itself will not be significantly reduced. Therefore, even if the diameter of the anchor rod A itself is made smaller, a significantly higher pull-out resistance can be ensured by increasing the number of cuts 5, 6, and so on. Therefore, it can be advantageously used underground where the ground is strong, and even when buried in soft ground, the diameter of the drilling hole for burial can be made smaller to maintain the bearing capacity of the ground. can. Furthermore, as will be explained in detail below, cuts 5..., 6... are made in the peripheral wall of the outer tube 2 of the anchor rod main body 1 at the factory, and it is only necessary to cast the cuts at the site. Since it is sufficient to drill a hole with a diameter approximately equal to the outer diameter of the retaining wall, it is 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 furthermore, a cylinder or a square column may be adopted as the inner tube. The shape of the substantially inverted U-shaped cut 5 is not limited to the strict inverted U-shape as in the above embodiment, but may be, for example, a substantially downward U-shape, a substantially inverted V-shape, or the like. The substantially vertically linear cut 6 may be provided not only in the axial direction of the anchor rod body 1 but also along the circumferential direction. Also, cuts 5..., 6... are
Although they are provided on substantially the same line along the axial direction of the outer tube 2 of the anchor rod main body 1, they do not necessarily have to be in this manner. They may be provided alternately on the line. The greater the number of cuts, the better, 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.

Further, in the above embodiment, the anchor rod main body 1 and the closing fitting 8 are separate members, but in the present invention, they may be formed integrally. The distal end opening of the anchor rod body 1 and the closing fitting may be attached by male and female screws. Furthermore, as shown in FIG. 4, a fitting hole 8d may be provided in the rear end 8c of the closure fitting 8, and the distal end of the inner tube 3 of the anchor rod body 1 may be press-fitted and fixed therein. In addition, for burial, the fifth
As shown in the figure, a closure fitting with a flat tip 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, a plurality of anchor rods A of the above embodiment are inserted into the ground 11 through holes 10 bored at predetermined intervals in the retaining wall 9 at an acute angle to the vertical axis of the retaining wall, as shown in FIG. Drive to desired depth. It is preferable that the anchor rod A is relatively short when driven into the upper part of the retaining wall 9, 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. Furthermore, if the ground is soft, it is preferable to use a long anchor rod.

Each anchor rod A driven in this way...
Gap 4 between outer tube 2 and inner tube 3 from rear end opening 1b
Then, the swelling agent 12 is injected and filled up to the positions where the cuts 5..., 6... are provided. If mortar is injected and filled into the gap 4 above the expanding agent 12 filled in this way, the expanding effect of the expanding agent 12 will be further enhanced. This swelling agent 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. Note that a mixture of this expanding agent with a small amount of cement, mortar, etc. may also be used.

The injected swelling agent 12 hardens and expands to about 12~
After 24 hours have elapsed, the maximum inflation pressure is reached, and as shown in FIG. 7, the tongues 7 stand up in an upward-opening manner as shown in FIG. 7, and the tongues 7 apply a pulling resistance to the anchor rod A. At the same time, as the cracks in the substantially vertically linear cuts 6 expand, the surrounding area of the anchor rod body 1 expands (the enlarged part 13), which imparts a frictional force, and the pull-out resistance of the anchor rod A becomes even higher. Become. Figure 8 shows tongue piece 7...
9 is a partial perspective view of the anchor rod main body 1 showing a state in which the anchor rod body 1 is erected upwardly and the cuts 6 have expanded in cracks, and FIGS. It is a Y line and ZZ line cross-sectional view. Coupled with the uprighting of the tongues 7, the area around the cut 5 of the outer tube 2 of the anchor rod body 1 expands (the enlarged part 14...), and compressive stress is created in the soil layer around the enlarged part 13 around the cut 6... is added and compaction occurs. As a result, a large frictional force is generated between the anchor rods A and the underground 11, and the pull-out resistance of the anchor rods A is further increased.

After the expansion of the expansion agent 12 is completed, a closing fitting is attached to the upper end opening of each anchor rod A protruding from the retaining wall 9.

As described above, the reinforcement of the retaining wall employing the above embodiment of the anchor rod of the present invention is completed. In addition,
If the upper end of each anchor rod A is undesirably exposed from the retaining wall, the upper end may be buried in concrete or the like. Further, the retaining wall 9 and the anchor rod A are engaged with each other by some means.

(Effect of the invention) An expansion agent is injected and filled into the gap between the outer tube and the inner tube of the anchor rod that is driven into the ground to form an enlarged portion and an upwardly opening tongue on the peripheral wall of the outer tube, and the anchor rod is pulled out. Can increase resistance. Therefore, it is an excellent anchor rod for reinforcing retaining walls. Since the swelling agent is injected and filled into the gap between the outer tube and the inner tube, the purpose can be achieved with a small amount of swelling agent. The straight pipe-shaped anchor rod body is simply driven or buried in the ground and the expansion agent is injected and filled, so construction is easy and many construction machines are not required. The anchor rod body can be mass-produced in a factory, and it is economical because it is easy to construct, and it can be constructed easily and quickly with little noise even in areas where houses and facilities are crowded.

[Brief explanation of drawings]

FIG. 1 is an exploded overall perspective view showing one embodiment of the present invention, and FIGS. 2 and 3 are W of FIG. 1, respectively.
- W-line and X-X cross-sectional views, FIGS. 4 and 5 are perspective views showing other embodiments of the closure fitting, respectively, and FIG. 6 shows the anchor rod of the present invention passing through the hole provided in the retaining wall. Fig. 7 is a cross-sectional view showing the state in which the tongues are erected upward in the ground due to the expansion pressure of the expanding agent, and the cracks in the incisions have expanded and the surrounding areas have expanded. FIG. 8 is a perspective view of the same essential parts, and FIGS. 9 and 10 are cross-sectional views taken along the Y-Y line and Z-Z line of FIG. 8, respectively, with the expansion agent omitted. A... Anchor rod, 1... Anchor rod body, 2... Outer tube, 3... Inner tube, 4... Gap,
5, 6... cut, 7... tongue piece, 8... closing fitting,
9...Retaining wall, 11...Underground, 12...Expanding agent, 1
3, 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 are a plurality of cuts that form an approximately inverted U-shape when the outer tube is stood upright, and a plurality of cuts that form an approximately vertical straight line. A closing fitting is attached to the opening at the tip of the anchor rod body, and an expansion agent is injected and filled into the gap formed between the outer tube and the inner tube from the opening at the rear end of the anchor rod body. An anchor rod characterized by a wet structure.