JPH0330646B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a temporary burial body for a removed anchor, and more particularly to a temporary burial body that is removed when unnecessary to form a cavity in the center of the anchor body. It is something.

[Conventional technology]

Due to their nature, anchors must be installed at a distance from the structure, and their presence may interfere with the construction work of other structures, or their installation may only be allowed during construction work. This often has to be removed. Therefore, there is a need for the development of a construction method that can easily remove the tensile material when it is not needed and also facilitates the removal work.

Conventionally, when constructing an anchor, a steel rod was temporarily buried inside the anchor by applying grease, etc. to the surface, and when it was not needed, it was pulled out and explosives were poured into the hole left behind to destroy the anchor, or water was , oil or the like was injected under pressure to split the anchor, and the tensile material was pulled out and removed (Japanese Patent Publication No. 8251/1983).

However, this means has the drawback that when pressure injection is used, local breakage causes leakage and pressure drops, and it is not possible to break the entire length. Furthermore, when the temporarily buried steel rod is pulled out, the steel rod and the hardening material are also stuck to the surface film, making it difficult to remove it easily.

The example shown in FIGS. 10 and 11 is an improved version of this means that is currently most commonly used (Japanese Patent Publication No. 54-22007). This example is
It is characterized by using a hollow member 21.

The anchor is placed in a hole 23 drilled into the ground 22.
It is formed by pouring hardenable material 24 such as mortar or cement. The tensile members 25 that are directly or indirectly connected to earth retaining structures or structures are made of prestressed steel rods or steel cables.
or by insertion into the curable material 24 after the curable material 24 has been cast but before it has hardened. The hollow member 21 is installed by the same means as the tensile member 25. Hollow material 21
A plug 26 is provided at the lower end of the tube to prevent the curable material 24 from flowing in.

However, if the hollow material 21 is destroyed or torn, the curable material 24 flows into the hollow material 21 from the plug 26 and does not function as the hollow material 21, making it impossible to remove the anchor (tensile material 25). The current situation is that there are many cases where this is impossible.

To remove this anchor, explosives or the like is put into the hollow member 21 and the curable material is destroyed by explosion or the like to reduce the fixing force of the curable material 24 to the tensile material 25, and the tensile material 25 is removed by jacking or the like. It is pulled out and removed.

However, since gunpowder or the like is used to reduce the fixing force of the curable material 24 to the tensile material 25, the work is dangerous, and there are also problems with vibrations and noise.

Therefore, in order to improve the problem of hardening material flowing into the hollow member and making it impossible to remove the anchor, the present inventors proposed a temporary structure in which a plurality of tensile members were bundled around the hollow member, as shown in Fig. 12. We conducted various research on how to arrange the buried body and used synthetic fiber rope27 as a temporary buried body.
(Japanese Patent Application No. 59-120535 (Japanese Unexamined Patent Publication No. 61-1725)).

According to this prior application, there is an advantage that the synthetic fiber rope 27 as a temporary buried body stretches and reduces its diameter when pulled out, making it easy to separate from the anchor body.

[Means for solving problems]

However, in such a conventional structure, when the anchor is removed, the synthetic fiber rope 27 directly contacts and adheres to the anchor body (hardened material), so the synthetic fiber rope 27 may be separated from the anchor body. In the early stages, there was a problem that a large amount of force was required.

Furthermore, when using the anchor, as shown in FIG. 12, since the curable material 24 is not attached to the portion 25A of the tensile material 25 that contacts the synthetic fiber rope 27, the entire circumference of the tensile material 25 is hardened. It is not attached and held by the adhesive material 24. Therefore, the tensile material 25
The supporting force of the anchor was weak, and the strength as an anchor was weak.

[Purpose of the invention]

The present invention was made in order to solve the above-mentioned problems, and its purpose is to be able to easily pull out the anchor with a small force when forming a cavity, and to reduce the adhesion force between the tension member and the anchor body when using the anchor. It is an object of the present invention to provide an improved temporary burial body for a removal anchor.

[Means for solving problems]

In order to achieve the above object, the first aspect of the present invention is to arrange a temporary burial body in which a plurality of tensile materials are tied around the center of a hole excavated in the ground, and to cast a hardening material. In removal anchors, in which the temporary buried body is removed in advance to form a cavity in the center when the tensile material is removed from the created anchor body, the temporary buried body is coated with a synthetic resin such as polyethylene that forms the central member. It is made up of a synthetic fiber rope coated with a synthetic resin such as polyethylene, and a synthetic fiber strand wrapped around the synthetic fiber rope.

Further, the second aspect of the present invention is to arrange a temporary burial body in which a plurality of tensile materials are tied around the center of a hole excavated in the ground, and to install a temporary burial body in which a hardening material is cast. In removal anchors where the temporary buried body is removed in advance to form a cavity in the center when removing the tensile material, the temporary buried body is a synthetic fiber rope that forms the central member or a synthetic resin coated with polyethylene or other synthetic resin. A fiber rope, a synthetic fiber rope or a synthetic fiber rope coated with a synthetic resin such as polyethylene, and a synthetic fiber rope coated with grease or a synthetic fiber rope coated with a synthetic resin such as polyethylene. The waterproof covering tape is made up of a waterproof covering tape and a synthetic fiber strand is wound around the waterproof covering tape.

[Action of the invention]

In the first aspect of the present invention, since the synthetic fiber rope coated with synthetic resin such as polyethylene, which is the central member of the temporary burial body, has a small fixing force of the curable material, the length of the anchor and the length of the temporary burial body are limited. If the length is short, it can be removed by pulling a synthetic fiber rope coated with a synthetic resin such as polyethylene.

In the second aspect of the present invention, the synthetic fiber rope or the synthetic fiber rope coated with a synthetic resin such as polyethylene, which is the central member of the temporary burial body, is not attached to the curable material, so when it is pulled out, Just slide off the layer formed by the grease and pull it out. Therefore, the synthetic fiber rope or the synthetic fiber rope coated with a synthetic resin such as polyethylene does not receive any resistance from the anchor body.

After pulling out a synthetic fiber rope or a synthetic fiber rope coated with a synthetic resin such as polyethylene, the waterproof covering tape and the synthetic fiber strands lose their support and become thinner when they are pulled out, resulting in a loss of strength from the anchor body. resistance becomes smaller.

Further, since the outermost part of the temporary buried body is made of synthetic fiber strands, a part of the hollow side of the tensile material is partially held by the anchor body.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a temporary burial body for a removable anchor according to an embodiment of the present invention will be explained with reference to FIGS. 1 to 9.

First, as shown in Fig. 2, several steel wires (12.7 mm diameter, 4 to 8 wires, but in this example, 6
A tensile structure 4 is prepared in which the books 2 are arranged at equal intervals in the circumferential direction, and tied to a binding body 3 such as tape or wire at arbitrarily short intervals.

Here, the temporary buried body 1, as shown in FIG.
Polyethylene resin 1 on the surface of synthetic fiber rope 1A
Synthetic resin coated rope 100 coated with B and grease 1C applied to the synthetic resin coated rope 100
and a waterproof covering tape 1D wrapped around a synthetic resin-covered rope 100 coated with grease 1C.
and a synthetic fiber strand 1E wound around the waterproof covering tape 1D. The synthetic resin coated rope 100 forms the central member.

This tensile structure 4 is inserted into a hole 5 that has been excavated at a predetermined depth and casting angle in the same manner as in normal anchor construction, and cement paste made of, for example, early-strengthening cement is injected as a hardening material 6. , the anchor trunk body 7 is created. At this time, since the waterproof coating tape 1D is coated around the grease 1C, the grease 1
The outflow of C can be prevented.

Next, the steps to be taken when it becomes necessary to remove the steel wire 2 from the anchor constructed in this manner will be described.

The constructed anchor is as shown in Figure 1.
Since the curable material 6 is in close contact with the outer periphery of the tensile structure 4, first, the synthetic resin coated rope 100 of the temporary buried body 1 buried in the center of the anchor body 7 is
pull out. This synthetic resin coated tape 100 is not attached to the curable material 6 or the steel wire 2 and is only in contact with the waterproof coated tape 1D via the grease 1C, so it can be pulled out with a small tension. By removing the synthetic resin coated rope 100, a cavity is formed in the center of the temporary buried body 1, and the waterproof coating tape 1D and the synthetic fiber strands 1E remain on the wall surface of the cavity. Then, the synthetic fiber strand 1E is pulled out together with the waterproof covering tape 1D. Since this synthetic fiber strand 1E is simply wrapped around the synthetic resin-coated rope 100 and the waterproof coating tape 1D, when the synthetic resin-coated rope 100 is removed, it loses its support and becomes thinner when pulled out, making it easy to pull out. I can do it. Therefore, by pulling and removing this synthetic resin coated rope 100, a cavity 8 is formed in the center of the anchor body 7 in parallel with the steel wire 2, as shown in FIG. No broken remains of the anchor body 7 remain. Here, the curable material 6
penetrates and fills the outer recess 1E' of the synthetic fiber strand 1E during casting, so the hollow side 2A of the steel wire 2
A part 7A of the anchor trunk body 7 is also formed. Then, a portion of the steel wire 2 is exposed around the side surface of the cavity 8.

In the state shown in FIGS. 4 and 6, in order to peel off the adhesion between the steel wire 2 and the hardenable material 6 and remove the steel wire 2, move the steel wire 2 toward the center of the cavity 8 located in the center. By pulling together the steel wire 2 and the hardenable material 6
The adhesion can be removed with a small amount of force.

This separation of the steel wire 2 is carried out by inserting the tensile material 2 into a push tube 9 having an inner diameter larger than the outer diameter of the tensile material 2 and approximately the same diameter, as shown in FIGS. 7 to 9.
This is done by pushing the push tube 9 into the depth direction of the anchor body 7 and moving the steel wire 2 in the radial direction of the cavity 8.

To explain in detail, in order to hold down the push pipe 9, as shown in FIG. It is designed to be fixed and pushed in. Wedge-shaped sockets 12 and 1 are provided in the fixing parts 11A and 11B between the jack 10, the tension member 2, and the push pipe 9.
3 are attached respectively, and the fixed parts 11A, 1
The structure is such that 1B does not loosen or slide. When the jack 10 is operated and the push tube 9 is pushed in, the push tube 9 cuts into the joint surface between the tensile material 2 and the curable material 6 and separates the tensile material 2 from the curable material 6. The peeled tensile material 2 curves toward the cavity 8 slightly ahead of the tip of the push tube 9 as a relief of the stress caused by peeling.
The exfoliation action is accelerated. As shown in FIG. 9, a portion of the push tube 9 is located in the dummy cavity 14 from which the tension member 2 has been removed, so that the jack 10 is not required to exert as much pushing force. Furthermore, since the inner diameter of the push tube 9 is the same as or slightly larger than the diameter of the tensile material 2, even if peeled pieces of the curable material 6 accumulate, there will be no problem in pushing the push tube 9. Therefore, pushing of the push pipe 9 along the tensile member 2 is ensured.

The steel wire 2 is sequentially peeled and pulled out using the method described above.
Remove and complete the stripping work.

According to the present invention having the above-described configuration, the interior of the anchor body 7 can be easily removed by simply removing the covering members (waterproof covering tape 1D, synthetic fiber strands 1E) after pulling out the synthetic resin-covered rope 100, which is the central member. The cavity 8 can be easily formed. Temporary burial body 1
Since the central member synthetic resin coated rope 100 and the covering member are slidably connected via the grease 1C, the tension required when removing the synthetic resin coated rope 100 to form the cavity 8 is small. This can improve safety and speed of removal work.

In addition, since the outermost part of the temporary buried body 1 is made of synthetic fiber strands 1E, the inner peripheral side 2 of the tensile material 2
A is partially held by the anchor body 7.
Therefore, the contact area of the tensile material 2 with the anchor body increases, the adhesive force between the curable material 6 and the tensile material 2 increases, and the anchor can be used as a strong anchor before removal of the anchor.

In the above embodiment, the temporary buried body 1 was composed of a synthetic resin-coated rope 100, grease 1C, waterproof coating tape 1D, and synthetic resin strands 1E, but the synthetic resin-coated rope 100 was made of mortar cement. Because the fixing force of the synthetic resin coated rope is small, the length of the anchor and the length of the temporary burial body are short, and the fixing force of the synthetic resin coated rope with the hardening material such as mortar and cement is the tensile strength of the synthetic resin coated rope. If the diameter is smaller than that, the grease 1C and the waterproof covering tape 1D can be omitted.

In this case, the steps of applying grease and wrapping waterproof covering tape can be omitted in the manufacturing process of the temporary buried body 1, which is economical.

〔Effect of the invention〕

As described above, according to the present invention, the temporary buried body for a removable anchor can be easily pulled out with a small force when forming a cavity, and the adhesion between the tensile material and the anchor body when using the anchor is improved. This has the effect of increasing the

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional configuration diagram of a temporary burial body for a removable anchor according to an embodiment of the present invention, Fig. 2 is an explanatory cross-sectional view of a tensile structure, and Fig. 3 is a cross-sectional view showing the construction state of the removable anchor. , FIG. 4 is a cross-sectional view showing a state in which the temporarily buried body has been removed, and FIG. 5 is a perspective view of the temporarily buried body.
Fig. 6 is a longitudinal cross-sectional view corresponding to Fig. 4, Fig. 7 and Fig. 8 are explanatory longitudinal cross-sectional views for peeling off the tensile material, Fig. 9 is an explanatory cross-sectional view of the same, and Fig. 10 is a conventional FIG. 11 is a cross-sectional view of the removed anchor, FIG. 12 is an explanatory cross-sectional view of the removed anchor when a conventional temporary burial body is used. 1...temporary buried body, 1A...synthetic fiber rope, 1
B...Polyethylene resin, 1C...Grease, 1
D... Waterproof covering tape, 1E... Synthetic fiber strand, 2... Tensile material, 4... Tensile structure, 5...
... Creation hole, 6... Curable material, 7... Anchor trunk, 8... Hollow, 9... Push pipe, 10... Jacket, 100... Synthetic resin coated rope.

Claims (1)

[Scope of Claims] 1. A temporary burial body with a plurality of tensile materials bound around it is placed in the center of a hole excavated in the ground, and the tensile materials are removed from an anchor body created by pouring a hardening material. In the case of removal anchors in which the temporarily buried body is removed in advance to form a cavity in the center, the temporary buried body consists of a synthetic fiber rope coated with a synthetic resin such as polyethylene that forms the central member, and a synthetic fiber rope coated with a synthetic resin such as polyethylene that forms the central member. 1. A temporary burial body for a removable anchor, characterized in that it is constructed of a synthetic fiber strand wound around a synthetic fiber rope coated with a synthetic resin. 2. A temporary burial body with multiple tensile materials bound around it is placed in the center of a hole excavated in the ground, and a temporary burial structure is installed in advance when removing the tensile materials from the anchor body created by pouring hardening material. In a removed anchor whose body is removed to form a cavity in the center, the temporarily buried body consists of a synthetic fiber rope forming the central member or a synthetic fiber rope coated with a synthetic resin such as polyethylene, and a synthetic fiber rope or polyethylene Grease applied to a synthetic fiber rope coated with a synthetic resin such as, etc., waterproof covering tape wrapped around a synthetic fiber rope coated with grease or a synthetic fiber rope coated with a synthetic resin such as polyethylene, A temporary burial body for a removable anchor, characterized in that it is constituted by a synthetic fiber strand wrapped around a covering tape.