JPH0733658B2 - Anchor head - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anchor head for fixing anchors on the ground, and more particularly to an anchor head for an anchor using a large number of small diameter synthetic resin fibers as a tension material.

[0002]

2. Description of the Related Art Conventionally, a tensile member made of steel such as a stranded steel wire has been used as a tensile member of an anchor. Such a steel tensile member may be rusted, and the rusted tensile member may be broken, which is a serious problem. For this reason, it is desirable to use a material that does not rust as the tensile material. As such a tension material which does not rust, for example, Japanese Patent Laid-Open No. 64-29521 and Japanese Utility Model Laid-Open No.
A tensile member made of fiber reinforced plastic (FRP) as described in Japanese Patent Publication No. 96927 is used.

[0003]

However, the tensile member made of the above-mentioned fiber reinforced plastic is a single rod-shaped member like the conventional tensile member made of steel. Even if a tensile member made of a material that does not rust easily is used, the same area as that of the conventional steel tensile member can be obtained with the same rod-shaped member as the conventional one, and a large adhesive force can be obtained. Can not.
For this purpose, insert a large number of thin synthetic resin fibers such as polypropylene into the holes, and inject the cement milk into the holes when the fibers are scattered, It is conceivable that the entire peripheral surface of (1) adheres to the cement milk to obtain a large adhesion area.

[0004] However, the problem in using such a synthetic resin fiber as a loose fiber as a tension material is how to fix the end on the ground side. As described above, in the case of a rod made of fiber reinforced plastic, it is possible to hit the tip of the rod with a wedge or the like to open the diameter and thereby hook the end portion of the rod to the anchor head. However, it is impossible to drive wedges with a large number of loose fibers, and it is necessary to develop an anchor head that uses a completely new fixing method.

The present invention has been made in order to solve the above problems, and in an anchor using synthetic resin fibers that do not rust as a tensile material, a large number of the thin synthetic resin fibers in a discontinuous fiber state. It is an object of the present invention to provide an anchor head capable of firmly fixing the anchor.

[0006]

The anchor head according to the present invention is used for an anchor using synthetic resin fibers as a tension material. A tension member insertion hole penetrates through a fixing member that fixes an anchor that is fixed on the ground. The inner diameter of the tension material insertion hole gradually decreases toward the ground. The ends of the thin synthetic resin fibers, which are the tension members of the anchor, are passed through the tension member insertion holes. Synthetic resin fibers remain in a state of many disjointed fibers. The disjointed synthetic resin fibers are arranged along the inner peripheral surface of the insertion hole so that the fiber layer becomes substantially uniform radially. A semi-cone-shaped cone having a hole on the peripheral surface is placed in the insertion hole to hold the small diameter synthetic resin fiber. The hardening material is filled in the tension material insertion hole, and the hardening material inside and outside the cone and the small diameter synthetic resin fiber are attached and integrated. The hardening material penetrates between the fibers and adheres thereto, and the hardening material has a substantially conical shape with the cone inside the tension material insertion hole.
The fibers are fixed by the cone-shaped hardening material to which the fibers are attached. As the small diameter synthetic resin fiber, polypropylene fiber, carbon fiber, polyethylene fiber or the like can be adopted.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on an embodiment shown in the drawings. In the figure, reference numeral 1 is a tensile member, and thin synthetic resin fiber is used. The small diameter is as small as several microns, and polypropylene fibers are used in the examples. A large number of these small diameter synthetic resin fibers are used in a separated state. Reference numeral 2 is a grout injection hose made of a steel pipe or the like. In the embodiment, a deformed hose having corrugated irregularities on the outer peripheral surface is used. Along the circumference of this grout injection hose 2, thin diameter synthetic resin fibers are bundled and arranged so as to form a layer. The layers of the small diameter synthetic resin are arranged evenly in the circumferential direction as shown in FIGS. The small-diameter synthetic resin fibers are bundled by the string 3 at positions separated by appropriate intervals in the longitudinal direction of the hose 2. The free length portion of the tension member 1 is passed through a free length sheath 4 made of synthetic resin such as polyethylene. The free length sheath 4 is filled with grease. The fixing portion of the tensile member 1 is left as it is in a small diameter synthetic resin fiber.

The anchor as described above is inserted into the excavation hole 5. The small diameter synthetic resin fiber that is the tensile member 1 is easily bent, but since it extends along the outer periphery of the grout injection hose 2,
It can be inserted into the excavation hole 5 so as not to bend. The cement-based grout material 6 is injected into the excavation hole 5 through the grout injection hose 2. While filling the grout material 6, the injection hose 2 is gradually pulled out from the excavation hole 5. The small-diameter synthetic resin fibers exposed at the fixing portion adhere to the grout material 6, and the anchor is fixed. Since the free length portion is passed through the free length sheath 4, the tension member 1 does not adhere and can be freely extended by applying a prestressing force.

FIG. 4 shows an anchor head for fixing the tension member 1 of the anchor, which is made of steel and has a disk-shaped fixing member 8.
A tensile member insertion hole 7 penetrates through the center of the. The inner diameter of the tension material insertion hole 7 is gradually reduced toward the natural ground side. A portion of the thin synthetic resin fiber, which is the tension material 1 and which is projected from the free length sheath 4, is projected from the ground into the tension material insertion hole 7 of the fixing member 8. The thin synthetic resin fibers are radially added to the inner peripheral surface of the tension member insertion hole 7 in a disjointed state. A semi-conical cone 9 is arranged in the tension member insertion hole 7 so as to press these thin synthetic resin fibers. Although a plurality of holes 10 are formed on the peripheral surface of the cone 9 in the embodiment, the cone 9 may be formed by a net.

While a large number of fibers are pressed against the inner peripheral surface of the tension material insertion hole 7 by the cone 9, a hardening material 11 such as cement-based grout material is filled and hardened. When the hardened material 11 is hardened, the hardened material 11 adheres to the fibers and the tensile member 1
Is fixed. Since the inner diameter of the tension material insertion hole 7 is gradually reduced toward the natural ground side, the hardened material 11 filled therein has a substantially conical shape. Therefore, unlike the wedge, the hardened material 11 does not engage with the inner peripheral surface of the tension material insertion hole 7 and come out. Moreover, each of the many fibers is attached to the hardened material 11 on all the circumferential surfaces thereof, and the connection is strong.

[0011]

The present invention has the above-mentioned structure and can obtain the following effects. Since the tensile material in a fiber state in which a wedge or the like cannot be driven is fixed by adhering the entire circumferential surface of each fiber to the hardening material, it is possible to fix the fiber material in the fiber state. The synthetic resin fiber is placed in the tension material insertion hole whose inner diameter gradually decreases toward the ground, and the hardening material is adhered and integrated by the hardening material, so the hardening material is wedge-shaped inside the insertion hole. There is no fear that it will come out. Since the fibers radially arranged in the tension material insertion hole are pressed by the cone, the fibers are spread radially without being concentrated in one place, and the tension material and the inner peripheral surface of the insertion hole are well meshed, and a stronger fixation is achieved. Is possible.

[Brief description of drawings]

FIG. 1 is an overall view of an anchor.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG.

FIG. 4 is a perspective view of an anchor head.

FIG. 5 is a sectional view thereof.

[Explanation of symbols]

 1 Tensile Material 2 Grout Injection Hose 3 String 4 Free Length Sheath 5 Drilling Hole 6 Grout Material 7 Tensile Material Insertion Hole 8 Fixing Member 9 Cone 10 Hole 11 Hardening Material

Claims (1)

[Claims] 1. A fixing member for fixing an anchor on the ground penetrates through a tension material insertion hole whose inner diameter is gradually reduced toward the ground, and a large number of loosened material serving as tension members of the anchor are inserted into the tension material insertion hole. The small diameter synthetic resin fibers are positioned and evenly arranged along the inner peripheral surface so that the fiber layer is substantially uniform in radial direction, and a hole is formed in the peripheral surface in a semi-conical shape so as to press the small diameter synthetic resin fibers. An anchor head characterized in that an opened cone is arranged, and a hardening material is filled in the tension material insertion hole, and the hardening material inside and outside the cone and the small-diameter synthetic resin fiber are attached and integrated to be fixed.