JPS5817792Y2 - End closure structure of earth anchor sheath - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement in the end closure structure of a sheath for an earth anchor.

Generally, earth anchors have a hole drilled in the ground.
There is a method of inserting an anchor tension wire such as P or C steel wire through a sheath into the anchor, and embedding the tip of the tension wire in concrete at the bottom of the anchor hole and fixing it.

In such conventional earth anchors, the tip of the sheath is left open, or the tip of the sheath is closed with a tension wire fixing device, and the anchor is inserted into the anchor hole and concrete is filled from outside the sheath. When filling the concrete, cement mortar penetrates into the sheath from the tip of the ground, making the length of the tension wire embedded in the concrete uneven, and as a result, the length of the tension wire receiving tensile stress cannot be confirmed from the outside. First, the elongation during tension becomes non-uniform, resulting in variations in the elasticity of the entire tension wire.

Furthermore, if the tip of the tension wire is not fixed to the tip of the sheath, the tension wire may come out during work and may not be buried to a sufficient length after concrete is filled.

In view of these points, the present invention allows the tip of the tension wire to be temporarily fixed without using special high-voltage fixing fittings, etc., and also prevents concrete mortar from entering the sheath during concrete filling. The purpose of the present invention is to provide an end-closing structure for an earth anchor sheath that can be closed to prevent any damage to the earth anchor. , the tension wire protrudes from the center part of the inner cap, a cement short cylinder is attached to the outside of the inner cap, and a cement short cylinder has a tip attached to the tip of the cement short cylinder. An outer cap is placed to close the outer cap, and the tip of the tension wire is made to protrude from the center of the outer cap, and cement is filled in the cement short cylinder to temporarily secure the tension wire to create a ground anchor. The end of the sheath has a closed structure.

Next, an example of implementation of the present invention will be described with reference to the drawings.

In the figure, reference numeral 1 indicates a tension wire rod for an earth anchor made of P and C steel wires.

This tension wire 1 is inserted into a sheath 2, and its tip protrudes from the tip of the sheath 2 by a length of concrete embedding.

The sheath 2 is a spirally wound pipe sheath, that is, a central part of a steel strip with a chevron-shaped protrusion 3 formed in the longitudinal direction, which is wound spirally and both edges are swaged to connect airtightly to form a cylindrical shape. using something.

An inner cap 4 having a tension wire 1 passed through the center thereof is fitted to the distal end of the sheath 2 to close the distal end of the sheath.

Further, on the outside of this inner cap 4, one end of a cement short cylinder 5 is fitted to the outer periphery of the distal end of the sheath 2, and is fixed with an adhesive tape 6.

This short cylindrical body 5 is made by cutting an ordinary spirally wound tube sheath having a diameter larger than that of the sheath 2 to a required length as appropriate, and is screwed together with the protrusion of the sheath 2.

The tip of the short cylindrical body 5 is closed with an outer cap 7, and the tension wire 1 is passed through the center of the outer cap 7 and protrudes.

The inner cap 4 and the outer cap 7 are located inside the short cylindrical body 5.
Cement mortar 8 is packed into the interior of the sheath 2, which airtightly closes the tip of the sheath 2 and temporarily secures the end of the tension wire 1.

The sheath 2 and tension wire 1 with their ends closed and temporarily secured in this way are inserted into the earth anchor hole 10 drilled from the ground surface or side wall, and concrete 11 is poured into the bottom of the hole 10 from the outside of the sheath 2. The protruding tip of the tension wire 1 and the sheath 2 are embedded in the concrete 11, and the fixing force of the concrete 11 fixes the tip of the tension wire 1.

The end-closing structure of the earth anchor of the present invention is constructed as described above, with a cap inside the tip of the sheath through which the tension wire is inserted, a short cylindrical body attached to the outside of the cap, and a cement mortar inside the short cylindrical body. By filling the ends of the sheath and temporarily fixing the tip of the tension wire, it is possible to prevent concrete from entering the sheath when pouring concrete for the anchor, and prevent the tension wire from entering. It is possible to apply tensile stress to a predetermined length, and the length for embedding and fixing the end of the tension wire is also constant, making it possible to obtain a predetermined desired fixing force.

Moreover, the structure is one in which the normally used sheaths are cut and connected, a simple cap is applied, and cement mortar used for anchors is used, and no high-strength fixing plates are used. Therefore, its price is low and its effects are tremendous.

[Brief explanation of drawings]

The drawings show an example of the implementation of the present invention, and FIG. 1 is a longitudinal sectional side view, and FIG. 2 is a longitudinal sectional view of the device in use. 1... tension wire rod, 2... sheath, 3...
...Chevron-shaped protrusion, 4...Inner cap, 5.
...Cement short cylinder, 6...Adhesive tape, 7...Outer cap, 8...Cement mortar, 10...Earth anchor hole,
11... Concrete.

Claims (1)

[Scope of utility model registration request] An inner cap that closes the tip of the sheath is placed on the tip of the sheath through which the anchor tension wire is inserted, and the tension wire is protruded from the center of the inner cap, and a cement short cylindrical body is attached to the outside of the inner cap. , an outer cap for closing the tip of the cement short cylinder is attached to the top of the cement short cylinder, and the top of the tension wire protrudes from the center of the outer cap, and the An earth anchor sheath with a closed end structure in which a short cylinder is filled with cement and a tension wire is temporarily secured.