JPH0726417Y2 - Permanent ground anchor - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a permanent ground anchor used for preventing falling of a civil engineering building structure, retaining soil on a slope, and the like.

[Prior Art] Permanent ground anchors may be provided for the purpose of preventing falling of civil engineering structures and retaining soil on slopes. Various types of permanent ground anchors have been developed and provided, but the method of fixing PC steel rods with anchor nuts is often used because of the small loss of the introduction force during tension fixing and ease of work. . This method is roughly configured by a plurality of PC steel wires embedded in the soil, anchor bolts that fix the PC steel wires to the ground, and anchor nuts that are screwed into the anchor bolts. .

The conical sleeve method, OSPA method, BBRV method, etc. are typical methods for fixing with an anchor nut.

Conical sleeve construction method The conical sleeve construction method is as shown in Fig. 7. One end of the anchor bolt 6 is processed into a taper shape, and a plurality of PC steel wires are set around this taper part, and further, the inner circumference The PC steel wire and the anchor bolt are integrated by pushing in the conical sleeve 1 processed into a taper shape.

OSPA construction method The OSPA construction method is to set a plurality of PC steel wires with button heads into one joint and fix them with anchor nuts.

BBRV construction method The BBRV construction method is to set a plurality of PC steel wires with button heads into one joint and joint them directly to the anchor bolts.

[Problems to be solved by the invention] However, in any of the above-mentioned construction methods, the outer diameter of the joint portion is larger than the outer diameter of the tension member composed of a plurality of PC steel wires due to mechanical reasons. There was a problem to raise.

When drilling according to the outer diameter of the tension material, when drilling the part where the joining tool will exist, it is necessary to change the setup to change the drilling diameter, and the labor required for such setup changing work, There was a problem that time and expense increased.

In addition, in the case of ground that partially collapses, a casing pipe is used to make a hole, and an anchor is inserted into the hole. However, in such a case, the casing pipe of the tension member cannot be pulled out, so that there is a problem that the casing pipe cannot be used despite the fact that there are many such grounds.

If the diameter of the drilled hole is adjusted according to the outer diameter of the joint, it is not necessary to change the setup. In addition, the casing pipe is prevented from coming off. However, if the diameter of the drilled hole is matched with the outer diameter of the joint, a lot of time and labor will be required.

In order to solve the above problems, the outer diameter of the connecting portion between the PC steel wire and the anchor bolt may be reduced.

The present invention has been made in view of such circumstances, and an object thereof is to provide a permanent ground anchor capable of reducing the outer diameter of the joint portion between the PC steel wire and the anchor bolt as compared with the conventional technology. There is a point to do.

[Means for Solving the Problem] The gist of the present invention is to provide a tension member that extends in the longitudinal direction of the drill hole, has one end reaching the tip of the drill hole, and has a locking portion at the other end, and a screw on the outer surface of the end. A permanent ground anchor comprising: an anchor bolt having: an anchor nut that is screwed with the anchor bolt; and a joint that joins the other end of the tension member and the anchor bolt, wherein the joint is an anchor. The anchor head consists of a head and a coupling.
A through-hole having an outer cylindrical shape and having a diameter smaller than the diameter of the locking portion and larger than the diameter of the tension member and penetrating both bottom surfaces and inserting the tension member; and a screw formed on the outer surface. The coupling has a substantially cylindrical outer shape, and is formed on the outer surface of the end of the anchor head and the screw for an anchor head that is screwed into the screw formed on the outer surface of the anchor head. The present invention relates to a permanent ground anchor characterized by having a screw and a screw for an anchor bolt which is screwed with the screw on the inner side surface.

[Operation] The operation of the present invention will be described with reference to FIGS. 8 (a) and 8 (b). FIG. 8 (a) and FIG. 8 (b) show an example of the prior art. FIG. 8 (a) is a front view of the anchor head, and FIG. 8 (b) is a view of the anchor head (joint portion). It is a side view.

Conventionally, as shown in FIGS. 8 (a) and 8 (b), a screw is formed on the inner surface of the anchor head 2 and the anchor bolt 6 is screwed and fixed inside the anchor head 2. On the other hand, in the present invention, since the anchor bolt 6 is not screwed into the anchor head 2, the outer diameter of the anchor head 2 can be reduced because the anchor bolt 6 is not screwed inside.

In the present invention, the coupling between the anchor head and the anchor bolt is performed by the coupling, but the increase in the outer diameter due to the mounting of the coupling is smaller than the decrease in the outer diameter of the anchor head.

Therefore, the connecting portion between the anchor head and the anchor bolt, that is, the outer diameter of the coupling can be reduced.

[Embodiment] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, quantities, and relative arrangements of the components described in this embodiment are not intended to limit the scope of the present invention to them unless otherwise specified. No, it is merely an example of explanation.

As shown in FIG. 1, the permanent ground anchor A according to the present embodiment has a PC (“prestressed concrete” and the like below) steel wire bundle 10, an anchor head 20, a coupling 30, and Anchor bolt 60 and anchor nut
40 and anchor plate 50.

The PC steel wire bundle 10 is composed of 14 PC steel wires 11 (PC steel material) and extends in the longitudinal direction of the drill hole, and one end thereof reaches the tip of the drill hole. Each PC steel wire 11 has a button head 11a (locking portion) having a circular cross section at the other end, as shown in FIG. The button head 11a is a PC steel wire 11 used in the BBRV method.
It is similar to the button head 11a that is processed at the end,
It is formed by cold working with a head machine. Although the number of PC steel wires is 14 in the present embodiment, the scope of the present invention is not intended to be limited thereto, and the present invention can be set to a suitable number for implementing the present invention. .

The anchor bolt 60 has a screw on its outer surface.

As shown in FIGS. 4 (a) and 4 (b), the anchor head 20 has a cylindrical outer shape and has a diameter smaller than that of the button head 11a and larger than that of the PC steel wire 11. It has a through hole (21) penetrating the bottom surface and a screw formed on the outer side surface.

The coupling 30 has a substantially cylindrical outer shape, and is shown in FIG.
Further, as shown in FIG. 5 (B), the anchor head screw 31 and the anchor bolt screw 32 having different inner diameters are provided on the inner side surface. As shown in FIG. 2, the anchor head screw 31 is screwed to a screw formed on the outer surface of the anchor head 20, and the anchor bolt screw 32 is screwed to the screw formed on the outer surface of the anchor bolt 60. It will be done.

The anchor nut 40 is screwed into the anchor bolt 60.

The anchor plate 50 is a flat square plate body having an insertion hole at the center and the anchor bolt 60 inserted through the insertion hole.

Next, a method of using the permanent ground anchor A in the ground having a portion that easily collapses will be described.

First, the anchor installation ground is drilled.

At this time, the casing pipe 70 is inserted into the hole while drilling. The casing pipe 70 is a thin cylinder made of steel.

Then, the PC steel wire bundle 10 (a bundle of 14 PC steel wires 11) is inserted. The PC head 11 and the coupling 30 may be screwed to the anchor head 20 in advance, and the anchor bolt 60 may be screwed to the coupling 30. The insertion of each PC steel wire 11 into the anchor head 20 is performed by inserting the end portion where the button head 11a is not formed into the through hole 21 of the anchor head 20.

Then, grout is injected into the hole in which the PC steel wire bundle 10 is inserted,
Then, the casing pipe 70 is pulled out.

Next, the anchor plate 50 is installed so that the anchor bolt 60 is inserted through the anchor bolt 60 insertion hole.

Next, the anchor nut 40 is attached to the anchor bolt 60.

Then, after the grout has hardened, prestressing is performed by a tensioning device such as a hydraulic jack, and the anchor nut 40 is tightened, and when the required prestressing force is obtained, the work is terminated.

Through the above steps, the permanent ground anchor A can be installed as shown in FIG.

When the outer diameter of the coupling 30 becomes large and the coupling 30 cannot be inserted into the casing pipe 70, the PC head 11 is attached to the anchor head 20 as shown in FIG. Insert into the casing pipe 70,
After grouting, the casing pipe 70 may be pulled out, then the coupling 30 may be attached to the anchor head 20, and the anchor bolt 60 may be attached.

Next, the operation of the permanent ground anchor A configured as described above will be described.

The PC steel wire bundle 10 transmits the prestressing force to the ground through the grout.

The button head 11a prevents the PC steel wire 11 from coming off from the anchor head 20.

The anchor bolt 60 together with the anchor nut 40 is a PC steel wire bundle.
The 10 is fixed to the ground, and the tension is transmitted to the PC steel wire bundle 10 during prestressing by the tensioning device. The coupling 30 connects the anchor head 20 and the anchor bolt 60.

The anchor plate 50 disperses and transmits the tension of the anchor bolt 60 to the ground.

Next, the effect of the permanent ground anchor A configured as described above will be described.

Conventionally, a screw is formed on the inner surface of the anchor head 20 and the anchor bolt 60 is screwed and fixed inside the anchor head 20. On the other hand, in the present invention, since the anchor bolt 60 is not screwed into the anchor head 20, the anchor head 60 is not screwed into the anchor head 20.
The outer diameter of can be reduced.

Although the coupling between the anchor head 20 and the anchor bolt 60 is performed by the coupling 30, the increase in the outer diameter due to the mounting of the coupling 30 is smaller than the decrease in the outer diameter of the anchor head 20. Therefore, the outer diameter of the coupling portion between the anchor head 20 and the anchor bolt 60, that is, the coupling 30 can be reduced. Specifically,
115 mm for the conical sleeve method, OSPA method and B
In the BRV method, it was set to 130 mm, whereas in this example, it was set to 110 mm.

Therefore, according to this embodiment, it is possible to reduce the labor, cost and time when the ground is drilled with the same diameter.

Also, since the ground is drilled with the same diameter, it is not necessary to change the setup. Therefore, according to this embodiment, it is possible to eliminate the labor, time and cost required for changing the setup.

Further, since the anchor head 20 can be inserted into the casing pipe 70, the casing pipe 70 can be used in the ground where partial collapse occurs or the like.

Although the button head 11a is used as the locking portion in the present embodiment, the scope of the present invention is not limited to this, and the shape of the present invention includes all shapes that can be fixed to the anchor head 20 of the present invention. .

Further, the shape of the anchor head 20 in the present invention is not limited to this embodiment, and may be, for example, the shape shown in FIG. In such a case, since the button head and other locking parts can be housed in the anchor head 20, the length of the coupling 30 can be shortened and the locking part is not damaged by the anchor bolt 60.

Further, although a plurality of PC steel wires 11 are used as the tension members 10, the scope of the present invention is not limited thereto, and other things in the present invention, for example, glass fiber tension members,
An aramid fibrous tension material or the like suitable for carrying out the present invention can be used.

[Advantages of the Invention] Since the present invention is configured as described above, it has the effects described below.

Since the present invention can reduce the outer diameter of the joint (coupling) between the anchor head and the anchor bolt as compared with the prior art, the labor, cost and time required for drilling the ground with the same diameter can be reduced. can do.

Further, if the ground is drilled with the same diameter, it is not necessary to change the setup. Therefore, according to the present invention, the labor, time and cost required for changing the setup can be eliminated.

Also, install the coupling 30 in the casing pipe,
Since the set of assembled tension members can be inserted, the casing pipe can be used in the ground such as with partial collapse.

[Brief description of drawings]

1 to 6 show an embodiment of the present invention,
Fig. 1 is a longitudinal sectional view of a permanent ground anchor, Fig. 2 is a side view of a connecting portion, Fig. 3 is a side view of a PC steel wire, Fig. 4 (a) is a front view of an anchor head, and Fig. 4 ( (B) is a side view of the anchor head, FIG. 5 (a) is a front view of the coupling in the direction of arrow A in FIG. 5 (b), FIG. 5 (b) is a side view of the coupling, and FIG. Longitudinal sectional views showing another embodiment of the anchor head, FIGS. 7 to 8 (b) show a conventional example, and FIG. 7 is a longitudinal sectional view of a joint portion according to the conical sleeve method. FIG. 8A is a front view of the anchor head according to the BBRV method, and FIG. 8B is a side view of the anchor head according to the BBRV method. A: Permanent ground anchor, 10: PC steel wire bundle, 11: PC steel wire, 11a: Button head, 20: Anchor head, 21
...... Through hole, 30 ...... Coupling, 31 ...... Anchor head screw, 32 ...... Anchor bolt screw, 40 ...... Anchor nut, 50 ...... Anchor plate, 60 ...... Anchor bolt,

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takeaki Teshima, 2-4-10 Higashi-Shimbashi, Minato-ku, Tokyo Within KFC Co., Ltd. (72) Keisuke Morita 2-chome, Higashi-Shimbashi, Minato-ku, Tokyo No. 4-10, KFC Co., Ltd. (56) Bibliography Flat 2-99125 (JP, U) Flat 55-54500 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A tension member extending in the longitudinal direction of a drill hole, having one end reaching the tip of the drill hole and having a locking portion at the other end, an anchor bolt having a screw on the outer surface of the end, and the anchor bolt. A permanent ground anchor comprising: an anchor nut that is screwed together; and a joint portion that joins the other end of the tension member and the anchor bolt, the joint portion including an anchor head and a coupling. The head has a cylindrical outer shape, and is formed on the outer surface and a through hole having a diameter smaller than that of the locking portion and larger than the diameter of the tension member and penetrating both bottom surfaces and inserting the tension member. The coupling has a substantially cylindrical outer shape, and an anchor head screw formed by engaging with the screw formed on the outer surface of the anchor head, and an outer surface of the end portion of the anchor bolt. Screw formed on Permanent Ground anchor and having a screwed screw anchor bolt and the inner surface.