JPS61233120A - Removable type anchor - Google Patents

Abstract

PURPOSE:To easily remove out anchors by providing an unfolding wedge with an axial tension member groove whose depth is reduced toward the downside, positioned on the tip end, a cavity, and a tension member for an unvoid type core material. CONSTITUTION:An anchor pit A is excavated, a removable anchor is penetrated from a wedge 11 side, a grout G is packed, and a tension is applied to the tensed end portion of the removable anchor. When removing the anchor, two cavitating materials 3 are drawn out to form cavities 4, and the core material 1 is pulled out. The depth of the tension member groove 13 is reduced toward the downside 15 of the wedge 11, and when the wedge 11 goes up on a tension member 2, the tension member 2 is pushed out to the outside from the plane portion 12 of the wedge 11. The member 2 can thus be released from the grout G simply by moving the member 2 on the inclined grove 13 of the wedge 11 toward the inside of the cavity.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a removable anchor that can reliably support an earth retaining wall or the like during use and that can be easily removed after use.

I〉Purpose of the invention [Industrial application field] construction.

[Prior Art] Various types of removal anchors have been developed for removing anchors from underground after construction is completed.

Among removable anchors, there is one in which a conical wedge portion that expands toward the tip is installed at the tip of an anchor core material, and an outer circumferential member is positioned around the core material and is restrained by the grout material.

Such removal anchors are removed in the following manner.

That is, upon removal, the core material is first pulled out.

Then, the wedge portion located at the tip pushes out the outer peripheral member located around the core material.

The extruded outer circumferential member destroys the grout material, and the anchor, which is released from its restraint, is removed from the hole.

E Problems to be Solved by the Present Invention] The horizontal removal anchor described above has the following problems.

(a) Since this method destroys the grout material by pushing the outer peripheral member outward by the force of the wedge, if the strength of the grout material is too strong, it will be difficult to destroy and impossible to remove.

(b) From the above, there is a limit to the strength of the grout material (200 kg/cd or less), and the anchor itself cannot be required to have very high strength.

(c) It is difficult to control the mixing ratio of the admixture (air) for adjusting the strength of the grout material.

[Object of the present invention] The present invention has been made in view of the above points, and it is possible to project the outer peripheral member of the core material outward without being affected by the strength of the grout material, thereby making it possible to To provide a removal anchor that is easy to remove.

In other words, the present invention has an unbonded type core material and an end-spreading tendon groove located at the tip of the core material that has an axial tendon groove that is deeper than the diameter of the tendon on the upper surface (and shallower on the lower surface). The present invention relates to a removal anchor comprising a wedge, an unbonded type hollow material adjacent to a tendon groove and creating a hollow hole after removal, and a tendon whose tip is fitted into the tendon groove of the wedge.

<■> Configuration of the Invention E Means for Solving Problem 1 Next, the removable anchor of the present invention will be explained based on the drawings.

The removal anchor of the present invention includes a core material 1 having a wedge portion 11 at its tip, a tendon material 2 located around the core material whose tip end fits into a tendon groove 13 of the wedge portion 11, and a core material 1 having a wedge portion 11 described later. It consists of a hollow material 3 located between each piece. (Figure 2) (A) Core material and wedge part (Figures 1 to 3) The core material 1 is an unbonded PCm wire, and the wedge part 1 is attached to the tip of the core material 1.
Install 1.

The wedge portion 11 is a member in which the core material 1 is fitted onto the axis of a conical member, and two portions having a cross-sectional shape symmetrical to the core material 1 are cut out.

Then, the core material 1 passing through the axis of the wedge portion 11 is fixed to the lower surface 15 of the wedge portion 11 with a fixture 16, so that the core material 1 and the wedge portion 11 are integrally formed. (Fig. 3) Furthermore, as shown in Fig. 1, a tendon groove 13 into which the tendon 2 is fitted in the axial direction is provided in the flat part 12 of each piece at a symmetrical position with respect to the core material 1. .

The tension material groove 13 is formed with an inclination so that it is deeper than the diameter of the tension material 2, which will be described later, on the upper surface 14 side of the wedge portion 11 and becomes shallower on the lower surface 15 side.

That is, the tension material 2 fitted in the tension material groove 13 fully enters the inside of the wedge portion 11 on the upper surface 14 side of the wedge portion 11, and
The plane portion 12 is exposed to the outside of the wedge portion 11 as it goes toward the 5 side.

(b) Tension material The tendon material 2 is made of a flexible PC steel stranded wire or the like, and its tip is fitted into the tendon groove 13 of the wedge portion 11.

(c) Unbonded PCm wire is used as the cavity material 3, and the core material 1
The two tension members are located parallel to the core member 1 and adjacent to the tendon member 2 at symmetrical positions with the tension member 2 in between.

The tip end thereof is held between the opposing flat parts 12 of each piece of the wedge part 11.

The diameter is such that the outer circumferential surface of the hollow material 3 can substantially close the tendon grooves 13 carved in the flat portions 12 that sandwich the hollow material 3.

That is, the hollow member 3 is located adjacent to the tendon groove 13 of the plane portion 12, and is located adjacent to the tendon above the wedge portion 11.

Next, a method of using the removal anchor of the present invention will be explained.

(a) Anchor action (FIG. 4) An anchor hole A is drilled by a known method, the removal anchor of the present invention is inserted from the wedge portion 11 side, and the grout material G is filled.

After the grout material G has hardened, a tension force is applied to the tensioned end of the removed anchor to serve as the anchor.

(b) Removal of hollow material (Figure 3.5) When removing the anchor, first pull out the two hollow materials 3 to create a hollow hole 4.

Since the hollow material 3 is made of unbonded type PC steel wire, it is easy to pull it out.

Since the hollow material 3 was adjacent to the tendon groove 13, the hollow hole 4 after removal is also adjacent to the tendon groove 13, and the two are connected as one space.

Further, above the wedge portion 11, the cavity 4 is located parallel to the core material 1 and adjacent to the tendon material 2.

(c) Pulling out the core material (Figure 3.5) After removing the hollow material 3, the core material 1 is pulled out.

Since the core material 1 uses an unbonded type PC steel wire, its drawing itself is easy.

However, since the core material 1 has a wedge portion 11 at its tip, the wedge portion 11 is raised by pulling up the core material 1.

The depth of the tendon groove 13 becomes shallower toward the lower surface 15 of the wedge portion 11.

As a result, the tendon material 2 whose tip end is fitted into the tendon material groove 13 is pushed out from the plane portion 12 of the wedge portion 11 as the wedge portion 11 rises.

The tendon material 2 is adjacent to the hollow hole 4, and the rising tendon groove 13 and the hollow hole 4 are connected as one space, so the tendon material 2 is pushed out into the hollow hole 4 without difficulty.

(c) Removal of tendon material By pulling up the wedge portion 11 over the entire length of the anchor, the tendon material 2 is pushed out into the cavity 4 over its entire length and released from the restraint of the grout material G.

Therefore, its extraction can be carried out extremely easily.

<[[>Effects of the Invention Since the present invention has been described above, the following effects can be expected.

(b) By removing the hollow material, a hollow hole is created adjacent to the tendon material.

Therefore, rather than pushing the tendon apart with the wedge, the tendon can be easily released from the grout by simply moving the tendon into the cavity using the inclined tendon groove of the wedge.

(b) Do not destroy the grout by forcing the tendons apart.

Therefore, it is possible to use a grout material with high strength, and it can be used as a highly reliable and strong anchor.

(c) Since it is not affected by the strength of the grout material, conventionally,
It is no longer necessary to manage the mixing ratio of admixtures, which was highly difficult.

[Brief explanation of drawings]

Fig. 1 2 An exploded explanatory diagram of the wedge portion used in the present invention Fig. 2: An explanatory diagram of the wedge portion of the anchor used in the present invention Fig. 3: An explanatory diagram of the tendon when pulling up the core material Nos. 4 to 5 figure:
Explanatory diagrams before and after removal of the hollow material 1: Core material 2: Tensile material 3: Cavity material 4: Cavity hole 11: Wedge portion 12: Plane portion 13: Tensile material groove 16: Fixture G Nigeraud material Applicant Large Seiken Construction Co., Ltd.Figure 1

Claims (1)

[Scope of Claims] An unbonded type core material, and a diverging wedge having an axial tendon groove located at the tip of the core material that is deeper than the diameter of the tendon on the upper surface and becomes shallower toward the lower surface. A removable anchor consisting of a section, an unbonded type hollow material that is adjacent to the tendon and the tendon groove and creates a hollow hole after removal, and a tendon whose tip is fitted into the tendon groove of the wedge section.