JPS6187018A - Removal type anchoring work - Google Patents

Abstract

PURPOSE:To easily drawn out a tension member by a method in which a removing cylinder is inserted with a tension member and a receiving part are connected with a rope, the receiving part is lowered by striking it, and the tension member is separated from grout. CONSTITUTION:When an anchor 1 is inserted into an anchor pit A and its anchorage length (a) is reached a given depth, a grout G is injected through the hollow of a core material 12 and hardened. Afterwards, a tension is given to the tensing end portion (b) of the member 11 by a clamper 4. The core material 12 is removed from the anchor 1 to form a hole 3, and the receiving part 21 of a remover 2 is inserted into the hole 3 by turning its opening 24 upwards. A removing cylinder 22 is then fitted on the member 11, and the receiving part 21 is lowered by striking it by positioning the tip of a striking bar 25 on the opening 24 of the part 21, whereby separating the member 11 from the grout G.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a removable anchor construction method that can reliably support earth retaining walls, etc. during use, and that allows the anchor to be easily removed after use.

T) Purpose of the invention "Industrial application field" construction.

[Prior Art] Various removable anchor construction methods have been developed in which the anchor is removed from the ground after construction is completed.

The present invention relates to a so-called core-handling removable anchor construction method in which the anchor is removed by creating a hollow hole and releasing the tension material from the restraint of the grout material.

The principle of the removable anchor construction method is to surround the core material with multiple PC steel wires and use it as a tension material.When removing the core material, the core material is first removed, and the tension material is released from the restraint of the grout material.
This method involves pulling out one tension member such as C steel wire and removing the anchor.

[Problems to be solved by the present invention] A removable anchor method using the core handling method as described above? In the program,
In addition to the problem of how to easily create large-sized hollow holes inside each PC steel wire, the following problems also exist.

(a) Since grout material wraps around the side that is in contact with the core material, the tendon material is surrounded by grout material.

Therefore, even after the core material is removed, it is not completely free from grout material.

Therefore, when pulling out the tension material, a strong enough force is required to not peel off the tendon material from the grout material on the outer circumferential side.

[Object of the present invention] The present invention has been made in view of the above-mentioned points, and it is possible to easily create a large-sized hollow hole inside a PC steel wire arranged in a cylindrical shape. The purpose of the present invention is to provide a removable anchor construction method that does not require large force to handle tendons.

/[''-, Structure of the Invention C Means for Solving Problems Next, the removable anchor construction method of the present invention will be explained based on the drawings. First, each member used in the present invention will be explained.

The present invention uses an anchor 1 having a cylindrical shape with a plurality of tendons 11 surrounding a core material 12 that is a hollow cylinder, and a removal tool 2 that releases the tendons 11 of the anchor from the grout material G. .

(A) Anchor (Fig. 2) The anchor 1 is composed of a hollow core material 12 and a tension material 11 located around the core material 12.

The distal end portion thereof is defined as a fixing length portion a, the proximal end thereof is defined as a closed end portion, and the space between the two is defined as a free length portion C.

-Tension material- As the tension material 11, a plurality of PC steel wires or the like having a circular cross section and slightly longer than the length of the insertion hole 4 are used.

And the tension material 11 in the part corresponding to the free length part C of the anchor
is covered with a sheath material or the like and filled with grease to form an unbonded type in which the tension material 11 is not directly restrained by grout material G, etc., which will be described later.

One core material The one core material 12 is a hollow cylindrical body made of a steel pipe or the like, and the periphery of the core material 12 is coated with grease to make it an unbonded type that is not restricted by grout OG, which will be described later.

And its diameter shall be sufficiently larger than the tension material 11,
The core material 12 is surrounded by a plurality of tendons 11.

<L'') Removal tool (Fig. 1) The removal tool 2 includes a bowl-shaped receiving member 21 and a plurality of removal cylinders 22, which are connected by a connecting cable 23 and formed integrally, and further includes the receiving member 2.
1 and a rod-shaped striking rod 25 that comes into contact with the ball and applies a blow.

1. Receptacle material - The receptacle 21 is a bowl-shaped member having an opening 24 having a diameter smaller than the diameter of the core material 12 of the anchor 1.

The material is made of steel or the like so that the bottom part can withstand the impact of the impact rod 25, which will be described later.

-Removal Tube- The removal tube 22 is a cylindrical body with both ends open, which is encased around all the tension members 11 of the anchor 1.

The tip is sharply carved in a plane that is not perpendicular to the axis of the cylinder.

The removal cylinder 22 is positioned around the receiving material 2 with its tip end facing in the same direction as the bottom portion of the receiving material 21.

One connecting cable One connecting cable 23 is a member that connects the receiving member 21 and the removal tube 22, and uses a flexible wire instead of a steel rod or the like.

The connecting cables 23 extend radially from the outer wall of the receiving member 21 to connect the receiving member 21 and the removal cylinder 22.

The length is such that when the removal tube 22 is encircled around each tension member 11 and the receiving material 21 is inserted into the hollow hole 3 after the core material 12 has been removed, the receiving material 21 is relative to the removal tube 22. It should be long enough to be positioned downward.

- Strike rod 1 The strike rod 25 is a steel rod with a diameter that can fit into the opening 24 of the receiving member 21.

Further, the tip thereof is formed into a spherical shape that can fit into the bowl-shaped receiving member 21.

And its length is longer than the entire length of the anchor hole A.

Next, the removable anchor construction method of the present invention will be explained.

(B) Insertion of anchor and injection of grout (Fig. 3) Insert the anchor 1 from the fixed length part a of the anchor 1 into the anchor hole A drilled in a predetermined ground/base.

When the fixing length part a reaches a predetermined depth, grout +JG is injected into the hollow part of the core material 12.

Although the grout material G hardens and binds the tension material 11 of the anchor length section a, the core material 12 is of an unbonded type and is therefore not restrained by the grout material G.

Further, the tension material 11 in the free length portion C of the anchor 1 is not directly restrained by the grout material G, but the sheath material and the like covering it are restrained by the grout material G.

After the anchoring length part a is fixed by the grout +JG, tension is applied to the tensioned end part of the tendon material 11 by the fastening part 4 to provide the anchoring action.

(b) Removal of tension materials After anchor 1 work is completed, remove anchor 1.

Removal of single core material First, the core material 12 is removed from the anchor 1.

Since the core material 12 is of an unbonded type, it is not bound by the hardened grout material G and is easy to handle.

When the core material 12 is removed, a hollow hole 3 surrounded by a plurality of tendons 11 is created.

- Attaching the removal tool = (Figs. 4 and 5) When removing the anchor 1, the fastening part 4 at the entrance to the anchor hole is removed, and the receiving member 21 of the removal tool 2 is inserted into the hollow hole 3 surrounded by the tension material 11. with the opening 24 facing upward.

On the other hand, the same number of removal cylinders 22 as the number of tension members 11 are respectively encircled around the tension members 11.

At this time, the removal tube 22 is positioned so that the tip thereof faces downward.

Next, the tip of the striking frame 25 is applied to the opening 24 of the receiving member 21, and a blow is applied from above through the striking frame 25.

[Function] (FIG. 5) When the hit receiving material 21 descends, the removal tube 22 is pulled toward the center of the hollow hole 3.

Removal 1n22 is attached to tension material 11, so tension material 1
1 is grout + A so that it is torn off at that point.
Freed from G's restraints.

Further, by applying a blow to the receiving material 21 and lowering the removing tool 2, the removing tube 22 loaded with 17 tension materials 11 is successively drawn to the center of the hollow hole 3.

Therefore, the tendons 11 are peeled off from the grout material G one after another.

At this time, the free length part C of the anchor 1 is directly attached to the grout material G (although it is not restrained by the grout material G), the sheath material covering it is torn off along with the groove material 11.

Note that there may be cases where the removal tubes 22 are too close to each other, making it difficult to lower the removal tool 2. In this case, each removal tube 2
It is also conceivable to place a spacer-like member between the two to allow a certain degree of closeness.

(C) Other Examples In the removal tool 2 of the above embodiment, the receiving member 21 and the striking frame 25 were formed independently, but the receiving member 21 and the striking frame 25 may be integrally formed with their tips fitted into the receiving member 21. It is also possible.

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

(a) Since the tension material is removed from the grout material by applying a blow to the removal tool that removed the core material, a large force is not required to pull it out.

(b) The anchors conventionally used in the removable anchor construction method had a removal device built into the main body itself, resulting in a complicated structure and drawbacks such as an increase in diameter and weight.

In this construction method, the removal tool, which is a removal device, is not built into the anchor body, so the structure of the anchor body is compact and simple, making it convenient to handle.

[Brief explanation of drawings]

Figure 1: An explanatory diagram of the removing tool used in the present invention Figure 2: An explanatory diagram of the anchor used in the present invention Figure 3: An explanatory diagram of the anchor work poem Figures 4 and 5: How to use the removing tool Explanatory diagram 1: Noncar 2: Removal tool 3: Hollow hole 4: Cotton knot 11: Tension material 12: Core material 21: Uke () tree 22: Removal I. 123: Connection cable 25:
Blow rod A: Anno one hole 140 shuttle 24

Claims (1)

[Claims] In a removable anchor method in which a core material located at the center of a plurality of tendons is removed and the tendons are pulled out, a removal tube is attached to the tendon and connected to the removal tube by a connecting cable. This removal method is characterized by inserting the receiving material into the hollow hole after the core material has been removed, impacting the receiving material to lower it, peeling the tendon from the grout material, and then pulling out the tendon. Anchor method.