JPH06336727A - Permanent anchor and constructing method therefor - Google Patents

Abstract

PURPOSE:To provide a permanent anchor, by which the diameter of a drilling hole can be made smaller, and which is economically constructed with an excellent working efficiency and has a strong resistance against corrosion. CONSTITUTION:In an anchor having an anchor head zone where the end parts on the free length side of corrosionproof steel members for tension are fastened onto a construction wall, a free length zone where the periphery of the corrosionproof steel members is covered with a sheath at the inside of a drilled hole following the head zone, and an anchorage length zone where the periphery of the corrosionproof steel members on the side of anchorage is not covered with the sheath, a wedge-shaped water-sealing part 5 composed of an elastic composition is provided at the boundary between the free length zone and the anchorage length zone. A spacer 8, of which the outside is made in curved surface shape or in diamond shape, is provided on the anchorage length zone. A plurality of top end caps each are put on the anchorage ends of a plurality of the corrosionproof steel members. These processes are performed individually or in combination.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent anchor used for preventing landslide on a slope and for stabilizing a pier.

[0002]

2. Description of the Related Art Anchors of this type include, for example, Japanese Patent Laid-Open No.
The 62-211423 publication discloses a tensile steel material covered with a corrugated sheath to enable double rust prevention in combination with the surrounding grout, and the free length of the tensile steel material disclosed in Japanese Examined Patent Publication No. 1-37532. It is known to use heat shrink tubing to join the corrugated tubing and straight tubing to the fixing length. It is also known to use a resin-coated full screw steel rod as a tensile steel material, and a method of injecting a pasty resin as shown in Japanese Patent Publication No. 3-38368 to form a water blocking portion is also known. Proposed.

[0003]

[Problems of the prior art] In the double rust prevention method described above, it is necessary to attach a corrugated sheath and to inject grout and the like, and the diameter of the fixing length portion becomes large.
There is a problem that the diameter of the hole for forming the anchor for forming this must be large.

In the method using the heat shrink tube,
There is a risk that the tube will be cracked when a tensile force acts, and the paste resin injection method requires labor and caution in construction, etc. .

The method using a fully threaded steel rod is easy to construct and does not require a large anchor drilling diameter, but the resin coating film thickness is 200 μm in order to obtain adhesion strength with concrete.
It was suppressed to a certain degree. Since it is so thin, care must be taken not to scratch the film during construction, and there is a concern that rust may occur due to the scratch.

The present invention has been made in order to solve the problem of the strength, and is a permanent anchor body which is easy to install, has a complete water stop without increasing the cost, and has sufficient corrosion resistance. It is the one we are trying to provide.

[0007]

The present invention has achieved its intended purpose by devising each constituent member constituting an anchor body and improving the method of inserting and assembling the anchor member. Some features are as follows.

(Water stop portion) A wedge-shaped water stop portion is formed at the boundary between the fixed length and the free length of the anticorrosion tensile steel material by an elastic material such as an elastic composition such as rubber or synthetic resin. It is preferable to make a cut in the water stop portion so that the tensile steel material is fitted from the outside.

(Tip Cap) A tip cap for rust prevention and protection is attached to each of the plurality of tensile steel members on the fixing side.

(Spacer) The spacer attached to the fixing portion of the tensile steel material is finished into a curved surface or a rhombus so that a corner portion toward the fixing end side does not occur.

(Tensile Steel Material) All tensile steel materials are previously subjected to anticorrosion treatment. It is preferable to coat the stranded wire of PC steel with an epoxy resin to a coating thickness of about 600 μm, and further coat the outer layer with it.
Use sand with embedded sand such as silica in a depth that does not reach the innermost layer of the coating.

(Formation method) A wedge-shaped water stopping portion is formed by an elastic composition at the boundary between the fixed length and the free length of the tensile steel material and is connected to a sheath covering the free length. Connect the opposite end of the sheath to the joint sheath that connects to the anchor head,
Complete the free length sheath.

[0013]

EXAMPLE FIG. 1 is a schematic view showing the overall structure of an anchor body in an embodiment, and is a longitudinal sectional view of the anchor body. Figure 2
1 is a vertical cross-sectional view for explaining the details of the anchor head portion of FIG. 1 and FIG.

In the figure, reference numeral 1 denotes a plurality of epoxy strands inserted in a hole 3 formed in a wall surface 2, and a plurality of epoxy strands are individually provided at the tips thereof for preventing rust such as plastic or resin coated metal. No.4 is attached and rust prevention is measured.
The separate caps are attached because it is impossible to deal with the case where the number of caps changes due to design deformation or the like, and the rust preventive effect is also taken. Reference numeral 5 denotes a water blocking portion formed in a wedge shape from a stretchable elastic composition such as silicone rubber, nitrile rubber, neoprene, or urethane resin, and is provided at the boundary between the free length and the fixing length of the epoxy strand 1.

The water stop portion 5 is cylindrical so that the grout injection hose 6 can be inserted through the center thereof, and the epoxy strand 1 is formed on the outer periphery thereof.
Is provided with a notch so that it is fitted and is wound and fixed with an anticorrosion tape 8 so as to be integrally connected to the end of the polyethylene sheath 7 on the free length side. As shown in FIG. 3, the anticorrosion tape 22 may be formed by first wrapping a petrolatum tape by 50% wrapping over the epoxy strand 1, the water blocking portion 5, and the polyethylene sheath 7, and further winding a self-bonding tape around the outer periphery.

Reference numeral 8 is a plastic spacer loaded to support the fixing length of the epoxy strand 1, so that the insertion tip side (fixing end side) is curved or rhombic so that it does not stick to the wall of the drilled hole 3 at the time of insertion. , Egg-shaped, etc.

An end of the polyethylene sheath 7 on the side opposite to the water blocking portion 5 side is connected to a joint sheath 9 which is inserted into the center hole of the anchor plate 10 of the anchor head and is in close contact therewith. Reference numeral 11 is a bearing pipe used for the connection, 12 is the same O-ring, 13 is the same water-tight packing, and 14 is a circular plate in contact with the outside of the anchor plate 10 that constitutes the tension anchorage while also helping the connection. is there. With this configuration, the sealing effect is enhanced, and the tension of the next epoxy strand 1 is sufficiently retained.

Numeral 15 is an anchor disk, which is circumscribed to the circular plate 14 via a ring nut 16 screwed onto the outer periphery thereof,
The epoxy strand 1 is pulled and held in the wedge hole via the wedge 17. Reference numeral 18 is a bush provided so as not to damage the epoxy strand 1.

Reference numeral 20 denotes a rust preventive cap that covers the portion of the tension fixing device composed of the circular plate 14, one end of the epoxy strand 1, the ring nut 16, etc., and an O-ring 19 is provided at the joint with the anchor plate 10. When installed, the space inside the cap is the same as in the free-length sheath.
Is filled.

In the anchor body of the present invention, first, a drilling hole 3 is opened in a required ground and a construction wall surface, and after water-stop treatment is applied to the hole,
The above-mentioned equipment is mounted in the drilled hole 3 and the prepared tensile steel material is inserted from the tip of the fixing length, and the primary grout is injected from the grout injection port to the fixing length as is conventionally done. It is formed through well-known or new processes such as forming a fixing long portion by means of, tensioning a tensile steel material, fixing a fixing member at an anchor plate portion, and secondary injection of grout to the outer circumference of the sheath.

In the anchor body of the present invention constructed and constructed as described above, the anchoring length struck at the water stop portion is protected by the corrosion of the tensile steel material and the tip cap and the grout, and the free length is the same as that of the tensile steel material. It is anticorrosive and protected by a rust preventive material, a sheath and an outer grout. Therefore, a heavy-corrosion-proof structure can be obtained without attaching a sheath to the fixing length or injecting grout between the sheath and the tensile steel material as in the conventional case.

[0022]

As described above, in the anchor body of the present invention, the anchoring length has a double anticorrosion structure by the anticorrosion tensile steel material and the surrounding grout, so that a sheath is attached to this portion as in the conventional case. Since it is not necessary to inject the anticorrosion material or the anticorrosion material, the fixing long portion can be formed to have a small outer diameter, and the drilling diameter can be small.

By forming a water blocking part with an elastic composition and using a curved or diamond-shaped spacer, it is easy to mount and insert, and the anticorrosion tensile steel material is stably held at the center of the drilled hole, and the inside of the sheath is protected. Leakage of the rust material to the outer circumference or intrusion of corrosive water into the sheath from the outer circumference can be reliably prevented.

As described above, the diameter of the drilled hole is small, the workability in construction is good, and the risk of damage to the steel material is small,
Since the position is maintained and the water is stopped, the construction cost is reduced.
The desired anchor effect is improved.

[Brief description of drawings]

FIG. 1 is a schematic vertical cross-sectional view for explaining the overall structure of an anchor body in an example of the present invention.

FIG. 2 is a similar vertical cross-sectional view for explaining the anchor head portion of FIG. 1 in detail.

FIG. 3 is a similar vertical cross-sectional view for explaining the water shut off part of FIG. 1 in detail.

[Explanation of symbols]

 1 Epoxy strand 2 Wall surface 3 Drilling hole 4 Tip cap 5 Water stop portion 6 Grout injection hose 7 Polyethylene sheath 8 Spacer 9 Joint sheath 10 Anchor plate 11 Bearing pipe 12, 19 O ring 13 Water stop packing 14 Circular plate 15 Anchor disc 16 Ring nut 17 Wedge 18 Bush 20 Anti-rust cap 21 Anti-rust material 22 Anti-corrosion tape

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Etsuji Ishibashi 1-3-12 Moto-Akasaka, Minato-ku, Tokyo Sumitomo Electric Industries, Ltd. Tokyo Head Office (72) Inventor Hiroshi Yamada 14-14, Ginza, Chuo-ku, Tokyo No. 14 Nitoku Construction Co., Ltd.

Claims (6)

[Claims] 1. An anchor head for fixing a free length side end portion of a corrosion-resistant tensile steel material to a construction wall surface, a free length portion in which a perimeter of the corrosion-resistant tensile steel material is covered with a sheath in a hole drilled following the head portion, and a sheath. A permanent anchor body having a fixing end portion on the fixing end side which is not covered by the above, and has a water blocking portion formed in a wedge shape by an elastic composition at a boundary between the free length portion and the fixing long portion. . 2. The permanent anchor body according to claim 1, wherein the water stop portion has an insertion hole for the grout injection hose therein, and a plurality of notches for fitting the anticorrosion tensile steel therein. 3. An anchor head for fixing a plurality of anticorrosion tensile steel end portions on a free length side to a construction wall surface, and a free length portion in which a sheath covers the outer periphery of the anticorrosion tensile steel material in a hole following the head. And an anchor having a fixing length portion on the fixing end side that is not covered by a sheath, characterized in that a plurality of anticorrosion tensile steel material fixing ends are individually covered with rust-preventing tip caps. And permanent anchor body. 4. An anchor head for fixing a free length side end portion of a corrosion-resistant tensile steel material to a construction wall surface, a free length portion in which a perimeter of the corrosion-resistant tensile steel material is covered with a sheath in a hole following the head portion, and a sheath. For anchors with unfixed fixing lengths on the fixing end side, the fixing lengths of anticorrosion tensile steel shall be fitted with spacers with curved or diamond-shaped outer perimeters so that corners facing the fixing end do not occur. Permanent anchor body characterized by. 5. An anchor head for fixing a plurality of anticorrosion tensile steel end portions on the free length side to a construction wall surface, and a free length portion in which the outer periphery of the anticorrosion tensile steel material is covered with a sheath in a hole drilled following the head. And a fixing length part on the fixing end side not covered by a sheath, and a wedge-shaped water stop part is formed by an elastic composition at the boundary between the free length part and the fixing length part, and the fixing length part of the anticorrosion tensile steel material. 5. A spacer having a curved or diamond-shaped outer periphery is attached to the fixing end, and a plurality of anticorrosion tensile steel materials are respectively attached to the fixing ends with tip caps for rust prevention. The permanent anchor body described. 6. A plurality of anticorrosion-treated tensile steel materials are attached to the fixing-side tips with a plurality of tip caps, and a spacer is attached to the fixing length portion of the steel material having a grout injection pipe. A wedge-shaped water stop made of an elastic composition is attached to the boundary between the long length and the free length so that one end of a sheath covering the free length portion is fixedly sealed, and the steel material that has undergone the above steps is attached from the fixing side. Inserting into the drilled hole, and connecting and sealing the opposite end of the sheath to a joint sheath connected to an anchor head fixing the free length side end, and forming a permanent anchor body.