JPH08209691A - Head part fixing structure of ground anchor - Google Patents

Abstract

PURPOSE: To tension a PC steel material in a straight line shape toward underground from a fixing part even if a back face curing pipe is not installed at a perpendicular or designed angle in the tensional direction of the PC steel material. CONSTITUTION: A sleeve pipe 2 to restrain a collapse of a hole wall is inserted into and fitted to an inside surface of an anchor hole 1, and a reinforcing rigid plate 3 is installed in an opening part 2a of this sleeve pipe 2. A PC steel material 5 inserted into a back face curing pipe 4 installed on this reinforcing rigid plate 3 is fixed by an anchor head 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground anchor head fixing structure.

[0002]

2. Description of the Related Art A conventional head anchoring structure of a ground anchor has a structure as shown in FIG. this is,
A sleeve tube 30 is inserted into the entrance of the anchor hole 20,
The opening of the sleeve tube 30 is covered with a stiffening plate 40,
The PC steel material 60 penetrating through the inside of the rear curing pipe 50 welded to the stiffening plate 40 is fixed by the anchor head 70.

In this head fixing structure, the back surface curing tube 50 is formed of a non-bendable steel plate, and the upper end thereof is welded to the through hole 40a of the stiffening plate 40.

[0004]

However, in the head fixing structure as described above, it is difficult to mount the stiffening plate at right angles to the fixing direction of the PC steel, so that the PC steel is eccentric in the rear curing tube. Inserted in the state. For this reason, there was a problem that the waterproof packing in the rear curing pipe was pressed in the eccentric direction, and a gap was formed on the opposite side.

Further, the PC steel material needs to be linearly tensioned from the fixing portion to the ground, but the stiffening plate must be at a right angle or a designed angle with respect to the tension direction of the PC steel material. For example, sometimes the back curing tube was bent.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has as its object to provide a method for mounting a PC steel material even if the stiffening plate is not attached at a right angle or a designed angle to the tension direction of the PC steel material. Is to provide a head anchoring structure of a ground anchor which can be tensioned linearly from the anchoring portion to the ground.

[0007]

In order to achieve the above object, the head anchoring structure in the ground anchor of the present invention has a sleeve tube attached to the entrance of the anchor hole and a supplementary member to the opening of the sleeve tube. In a head anchor fixing structure of a ground anchor in which a rigid steel plate is covered and a PC steel material penetrating the inside of a rear surface curing tube attached to a through hole of the stiffening plate is fixed by an anchor head, the rear surface curing tube is a flexible tube,
A structure in which a waterproof packing is provided inside the lower part thereof, the back curing tube is formed of a thin steel plate, and the back curing tube is formed from a through hole of a stiffening plate. Are also small in diameter and are attached at appropriate intervals to the edge of the through-hole, and the waterproof packing is made of synthetic rubber or swellable rubber. It is.

[0008]

The back curing tube is a flexible tube, and a waterproof packing is provided inside the lower portion of the back curing tube.
Since it bends in the tension direction of the C steel material, even if the stiffening plate is not attached at a right angle or a designed angle to the tension direction of the PC steel material, the PC steel material is linearly formed from the fixing portion toward the ground. Not only can it be tensioned, but it also prevents the water-stop packing inside the rear curing tube from shifting.

Further, since the rear curing pipe is formed of a thin steel plate, it is possible to follow the PC steel in the tension direction.

Further, since the rear curing tube has a diameter smaller than that of the through hole of the stiffening plate and is attached with an appropriate interval between the rear curing tube and the edge of the through hole, it can be freely bent in any direction. .

Since the waterproof packing is made of water-resistant synthetic rubber,
Can completely prevent water from entering the rear curing tube.

Since the waterproof packing is a swellable rubber, swelling by water completely prevents water from entering the rear curing tube.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a cross-sectional view of the head anchoring structure of the ground anchor of the present invention, and FIG. 2 is a cross-sectional view of the head anchoring structure of the ground anchor in which the stiffening plate is not mounted at right angles to the tension direction of the PC steel. 3 is a sectional view of the back curing tube.

In the ground anchor head fixing structure of the present invention, the sleeve tube 2 for suppressing collapse of the hole wall is inserted into the inner surface of the anchor hole 1, and the stiffening plate 3 is provided in the opening 2a of the sleeve tube 2. It is constructed by fixing the PC steel material 5 inserted into the back surface curing tube 4 attached to the stiffening plate 3 with the anchor head 6. The PC steel material 5 uses a PC steel strand, a PC steel wire and a PC steel rod.

The rear curing tube 4 has an upper large-diameter portion 4a and a small-diameter cylindrical portion 4b integrally formed of a thin stainless steel plate, and a flange portion 4c around the large-diameter portion 4a is fixed to the stiffening plate 3 by a supporting plate 7. A sheet packing 12 is provided around the flange 4c and is bolted.

As described above, since the cylindrical portion 4b has a small diameter, a predetermined gap 8 is formed between the cylindrical portion 4b and the edge of the through hole 3a of the stiffening plate 3, and the rear curing pipe 4 can be freely formed in the gap 8. It bends.

This is because the rear curing pipe 4 is formed of a thin stainless steel plate as described above, and the cylindrical body 4b has a small diameter. It is bent at the boundary 4d.

The rear curing pipe 4 is filled with a waterproof material such as grease or urethane resin, and a waterproof gasket 9 made of synthetic rubber is attached to a lower portion thereof, and the waterproof gasket 9 has an appropriate thickness. Since it is provided, it prevents infiltration into the inside of the rear curing tube 4.

As shown in FIG. 2, the water blocking packing 9 has a thickness for bending the back surface curing pipe 4 in the direction of eccentricity of the PC steel material 5, and assuming that the back surface curing pipe 4 is bent in a predetermined direction. However, the waterproof packing 9 does not shrink. Therefore, even if the back surface curing tube 4 bends in a predetermined direction, sufficient water stopping performance can be ensured.

As described above, since the waterproof gasket 9 can ensure sufficient waterproof performance by following the bending of the rear curing tube 4, the PC steel material 5 can be tensioned without bending.

When the waterproof packing 9 is made of swellable rubber, it swells with groundwater or the like, so that it is possible to prevent the back curing pipe 4 from being flooded.

FIGS. 4 and 5 show another embodiment of the water-stop packing 9. FIG. 4 shows a water-stopping fin 10a provided on the inner wall of a hole 10 into which the PC steel material 5 is inserted. In addition, the fins 10a can sufficiently secure the water stoppage.

In FIG. 5, the diameter of the hole 10 is gradually reduced, and the upper end portion is formed to have a diameter substantially the same as the outer diameter of the PC steel material 5 or slightly smaller. Therefore, since the PC steel material 5 is inserted while the hole 10 is expanded, the water stoppage can be sufficiently ensured also in this case.

[0024]

According to the present invention, the back curing pipe is a flexible pipe, and a waterproof packing is provided inside the lower part of the pipe, so that the back curing pipe is bent in the tension direction of the PC steel material. Even if it is not installed at a right angle or a designed angle with respect to the tension direction, the PC steel can be tensioned linearly from the anchoring part toward the ground, and the displacement of the waterproof packing in the rear curing pipe can be prevented. .

Since the rear curing pipe is formed of a thin steel plate, it is possible to follow the PC steel in the tension direction.

The rear curing tube has a smaller diameter than the through hole of the stiffening plate, and can be flexed freely in any direction by being attached at an appropriate distance from the edge of the through hole.

Since the water-stop packing is a swellable rubber, swelling by water completely prevents water from entering the rear curing tube.

[Brief description of drawings]

FIG. 1 is a sectional view of a head anchoring structure of a ground anchor.

FIG. 2 is a cross-sectional view of a head anchoring structure of a ground anchor in a state in which a rear curing tube is bent.

FIG. 3 is a sectional view of a rear curing tube.

FIG. 4 is a cross-sectional view of another back curing tube.

FIG. 5 is a cross-sectional view of another back surface curing tube.

FIG. 6 is a sectional view of a conventional head anchoring structure of a ground anchor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Anchor hole 2 Sleeve tube 2a Opening 3 Stiffening plate 3a Through hole 4 Back curing tube 5 PC steel material 6 Anchor head 7 Support plate 8 Gap 9 Waterproof packing

Claims (4)

[Claims] 1. A sleeve tube is attached to an entrance of an anchor hole, and an opening of the sleeve tube is covered with a stiffening plate.
In the head anchoring structure of the ground anchor, in which the PC steel material penetrating through the rear curing pipe attached to the through hole of the stiffening plate is fixed by an anchor head, the rear curing pipe is a flexible pipe, and water is stopped inside the lower part thereof. The head anchor structure of the ground anchor characterized by packing. 2. The head anchor structure for a ground anchor according to claim 1, wherein the rear curing pipe is formed of a thin steel plate. 3. The back curing tube according to claim 1, wherein the back curing tube has a smaller diameter than a through hole of the stiffening plate, and is attached at an appropriate distance from an edge of the through hole. Ground anchor head anchoring structure. 4. The head anchoring structure for a ground anchor according to claim 1, wherein the waterproof packing is made of synthetic rubber or swellable rubber.