JP2924944B2 - Spacer for anchor tendon - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art A lantern-shaped spacer made of a steel plate is already known as a spacer used for a fixing length portion of a PC tendon in a permanent anchor body. This is, as shown in FIGS. 3A and 3B, cylindrical holding parts 2 and 3 at both ends,
It comprises a support portion 5 having a cut 4 in the axial direction of the circumference connecting the two cylindrical portions. Each of the support portions 5 is curved outward and swells, and is thus called a lantern. In the figure, reference numeral 17 denotes a welded portion of the support portion 5 to the cylindrical grip portions 2 and 3.

[0003]

Although the above lantern has sufficient strength and sufficient support for the tendon material, its manufacture requires punching, bending, and welding of steel plates, and requires a lot of processing and cost. . In addition, when used, there is a disadvantage that it is easily corroded by intrusion of groundwater, etc., and if coating such as plating is performed to prevent this, it will be more troublesome, and the coating layer will be easily damaged at the time of installation. It is hardly enough, for example, because the scratches cause corrosion.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a spacer formed of a synthetic resin such as polyethylene to eliminate the fear of corrosion .
In order to improve operability such as mounting and positioning of the spacer, a cut is provided in the cylindrical grip portion of the spacer, or a cut is further added .

[0005] The upper SL spacer preparing a thermoplastic synthetic resin, a bulge outwardly of the support portion, the support portion may be formed allowed compression than the axial outer under heating. The details and other features of the present invention will be described with reference to examples.

[0006]

1A and 1B are a front view and an II sectional view of a spacer 1 according to an embodiment. In the figure,
Numerals 2 and 3 denote cylindrical grips provided at both ends, respectively. The grips 2 and 3 are connected by a support 5 having a plurality of circumferential cuts 4 around the circumference, and are integrally formed of polyethylene. Is formed.

The outer diameter of the cylindrical gripping parts 2 and 3 is 48 mm,
The wall thickness including the support portion 5 is 4 mm. And the support part 5
Initially there is no curvature and the length between both ends of the cylindrical gripping parts 2 and 3 is 3
What was 00 mm, while being heated above the softening temperature of the resin, was compressed inward from the outside in the axial direction, expanded radially outward from the central part and curved, and had a length of 280 mm.
It is formed by shrinking to.

When the spacer 1 having the above structure was used for the permanent anchor shown in FIG. 2, it was found that it did not corrode and had sufficient strength to be practically used. The following processing was performed before actually attaching to the anchor. As a result, the operability of the anchor mounting work such as the insertion of the tendon material has been improved.

[0009] Both or one of the cylindrical holding parts 2, 3
When a cut 6 of about 0.5 mm is provided, as shown in FIG. 2, a spacer is easily inserted into the tip of a deformed PC steel rod 9 having a diameter of 36 mm to be inserted into the drilled hole 8 of the rock, and if necessary, the cut 6 is pushed. It can be opened and covered from the side.

Further, in order to move the steel bar 9 on the above-mentioned steel bar 9 by the above-mentioned insertion and positioning, the operation is further facilitated by providing a plurality of cuts 7 from both ends in addition to the cut 6. Further, even if the spacer hits the hole wall or the steel rod during the operation, there is no fear that the plating is damaged and the anticorrosion property is lost as in the conventional case.

The spacer having the above-described structure is formed by extruding a thermoplastic synthetic resin such as polyethylene or polyvinyl chloride into a non-curved support portion by extrusion molding, and then heating the support portion in a heated state. The lower part is pressed relatively toward the center from both ends and compressed, the center part of the support part is expanded outward, and if it is cooled in a curved state, it can be easily manufactured, and the cost can be reduced.

FIG. 2 is a conceptual view from a side cross section showing the structure of a permanent anchor formed in a drill hole 8 provided in a rock.
The inside of the hole 8 is divided into a head portion 10 at the entrance, a free length portion 11 at the center, and a fixing length portion 12 at the back. Deformed PC inserted into the hole 8
The steel rod 9 is fixed by filling with cement grout or the like while being supported by the spacer 1 in the fixing length portion 12.

The head 10 is provided with a nut 13, a cap 14, a joint sheath 15 and the like, and is fixed in tension. Reference numeral 16 denotes a protective tube that surrounds the steel rod 9. Although the embodiment uses the deformed PC steel rod 9 as the tendon, another tendon such as a synthetic resin-coated PC steel strand may be used. The use of this synthetic resin coating has the effect that the coating is hardly damaged by the spacer.

The spacer can be easily formed by pressing and heating and compressing using a thermoplastic synthetic resin as in the above embodiment, which is economical. However, if necessary, a thermosetting resin may be used. It may be manufactured by another manufacturing method.

[0015]

Since the spacer of the present invention is made of a synthetic resin, it has good anticorrosion properties and, due to its structure, has good operability in attaching to a tendon. During the same operation, the spacer and PC
There is also little occurrence of defects due to scratches in the steel material. Fabrication is easy and production costs are reduced.

[Brief description of the drawings]

FIG. 1A is a front view of an embodiment of the present invention, and FIG. 1B is a sectional view taken along line II of FIG.

FIG. 2 is a conceptual diagram from a side cross section showing a configuration of a permanent anchor.

FIG. 3A is a front view of a conventional spacer, and FIG.
It is I sectional drawing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spacer 2, 3 Cylindrical gripping part 4 Break of support part 5 Support part 6 Cut 7 Notch 8 Drilling of rock 9 Deformed PC steel rod 10 Head 11 Free length part 12 Fixing length part 13 Nut 14 Cap 15 Joint sheath 16 Protection tube 17 Weld

Claims (2)

(57) [Claims] 1. A cylindrical grip at both ends made of synthetic resin,
該把connecting the lifting unit and the support unit having a plurality of cuts in the axial direction circumferentially is formed, and the support portion is curved radially outward from the axially central portion, the shaft in a cylindrical gripping portion A spacer for an anchor tendon, which is provided with a cut in the direction . 2. One or more notches on the outer end side of the cylindrical gripping part.
The anchor tension according to claim 1, wherein the anchor tension is provided.
Spacer for upholstery.