JP2002047651A - Anchor construction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anchor construction method capable of easily removing an anchor or preventing the anchor from becoming an obstacle to the post-work even when it is dead-buried after anchor bearing power becomes unnecessary. SOLUTION: An anchor body 10 expandable by injecting a grout F is installed at an anchor fixing position in a shrunk state, and the anchor body 10 is expanded by injecting the grout F into it. The anchor body 10 is formed into a shape having a face 13 exerting a bearing pressure when it is expanded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anchoring method, and more particularly, to an anchoring method with improved processing when an anchor becomes unnecessary.

[0002]

2. Description of the Related Art As an underground anchor, as shown by reference numeral 1 in FIG. 1, a tendon (a linear member on which a tension acts as an anchor supporting force acts) due to a frictional force between the ground G and the surface of the anchor 1. 2) are often configured to exhibit anchor supporting force.

In some cases, it is difficult to obtain a necessary and sufficient anchor supporting force only by the frictional force between the ground G and the surface of the anchor 1. Therefore, for example, an anchor 3 having a shape as shown in FIG. 12 may be used. In the anchor 3 of FIG. 12, the surface indicated by reference numeral 4 exerts a so-called “bearing force” (or proof stress).
This is advantageous in terms of anchor supporting force.

However, since the conventional anchor shown in FIGS. 11 and 12 is formed by fixing the tendon 2 with cement or mortar, after the anchor supporting force becomes unnecessary, the anchor or the tendon 2 is fixed. It is difficult to remove and reuse it. Then, for example, after the anchor supporting force becomes unnecessary, the anchors shown in FIGS. 11 and 12 may be buried and killed. There is a problem that anchors and tendons which are used as obstacles for construction work.

[0005]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above-mentioned problems of the prior art, and can be easily removed when the anchor supporting force becomes unnecessary.
Alternatively, the purpose is to provide an anchoring method so that burying and burying does not hinder subsequent construction.

[0006]

According to the anchoring method of the present invention, a step of installing an inflatable anchor body in a contracted state at an anchor anchoring position by injecting an injecting material, and injecting the injecting material into the anchor body. And an inflating step, wherein the anchor body is configured in a shape having a surface that exerts a supporting pressure when inflated.

Here, the injection material is a liquid (for example, water), and it is preferable that a supply line for supplying the injection material liquid from the ground side into the anchor is provided.

According to the present invention having such a configuration, by supplying water to the anchor body from the ground side via the supply line, the anchor body expands from a contracted state and has a surface which exerts a bearing pressure. Shape. That is, an anchor body that is advantageous for exhibiting the anchor supporting force can be formed by injecting water without using cement or mortar. At this time, the supply line is closed so that the injection material (liquid such as water) does not escape from the anchor body.

When the above-described anchor is removed from the anchoring position, according to the anchor method, the anchor is contracted by discharging liquid (for example, water) from the anchor. Since the contracted anchor body can be easily moved from the anchor anchoring position, it is already withdrawn during post-construction work. Therefore, it is possible to prevent the anchor, which does not need to exert the anchor supporting force, from being an obstacle to the post-construction work.

Alternatively, earth and sand are used as the injection material,
It is preferable to provide a supply line for supplying earth and sand from the ground side into the anchor body.

[0011] According to this structure, if the anchor which no longer needs to exhibit the anchor supporting force is buried and the anchor body is buried after collecting the tendon, the portion of the anchor which remains in the ground is only soil and bag. Therefore, it does not become an obstacle. Furthermore, when the anchor body is made of a bag made of biodegradable material, the anchor body melts and disappears in a relatively short period of time, leaving only the soil and sand that had been in the bag until then. I do. As a result, in a relatively short time,
Return to the same state as the original ground (before the anchor method was applied).

Further, according to the anchor method of the present invention, a step of installing a casing pipe to an anchor anchoring position, and a step of installing a casing made of a flexible material (for example, rubber) with a plurality of packers made of flexible material (for example, rubber). Inserting the tendon around the cover into the casing pipe; moving the cover with the tendon around the anchor to the anchor anchorage point; and positioning the cover outside the casing pipe at the anchor anchorage point And a step of supplying high-pressure water into the packer from high-pressure water supply means on the ground side through a high-pressure water supply line to expand the packer.

[0013] When removing the anchor constructed by the above-mentioned anchoring method, a step of draining high-pressure water through a high-pressure water supply line to shrink the packer, and removing the tendon wrapped around the cover from the ground. And moving the cover containing the packer from the anchor anchoring position by pulling the cover to the side.

By retracting the packer and the cover acting as an anchor body from the anchor anchoring position, the anchor body is no longer present during post-construction. Therefore, if the casing pipe is removed by the above-mentioned known method, there is no obstacle to post-construction work.

When implementing the anchor method of the present invention,
It is preferable to use an anchor which is configured to be inflatable and contractible, is connected to a line for injecting or discharging the injection material, and is configured to have a surface that exerts a supporting pressure when expanded.

In carrying out the anchoring method of the present invention,
An anchor characterized by being configured to be inflatable / contractible, connected to a line for injecting or discharging an injection material, and configured to have a surface that exerts a supporting pressure when inflated. Preferably, it is used.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a state where an anchor body used in the present invention is expanded. A tendon 12 to which a tension or a tension acts acts is wrapped around an anchor body (in a state in which it is inflated by filling contents to be described later) indicated by reference numeral 10 as a whole. Since the surface denoted by reference numeral 13 exerts a so-called "bearing force", it is configured to have an advantageous shape (compared to an anchor as shown in FIG. 11) to exert an anchor supporting force. Here, the tendon 12 is made of, for example, a PC steel wire.

The anchor body 10 is made of, for example, a woven fabric. As the woven fabric, for example, Japanese Patent Laid-Open No. 7-216
A woven fabric manufactured using the device described in JP-A-684 is preferred. The materials used for the woven fabric include general-purpose fibers such as polyester fiber, nylon fiber, and vinylon fiber,
High-strength fibers such as amilad fibers can also be used. Further, materials other than woven fabric can be used. In addition,
In order to prevent the anchor body 10 from being damaged, the anchor body 10 may be configured as a double-layer or a multi-layer structure of the woven fabric.

As the contents (injection material) to be filled in the anchor body 10, a fluid F, for example, a liquid (water or the like) or a granular material (sand or the like) is used. This fluid F is denoted by reference numeral 10I.
Are connected to a fluid supply source (not shown) and pressure supply means (fluid pump, etc.) installed on the ground side via a supply line indicated by.

In order to prevent a situation in which the fluid F escapes and the expansion state cannot be maintained when the anchor body 10 is exerting a supporting force (proof strength), a connection point between the anchor body 10 and the supply line 10I is prevented. Is the fluid F
In order to prevent leakage of pressure and pressure, the sealing member 16 is used.

Next, the installation procedure and operation of the embodiment of FIG. 1 will be described. First, the anchor body 10 in a contracted state is installed at a predetermined position by a method similar to the conventional anchor method. Specifically, as shown in FIG. 2, excavation is performed to a predetermined depth of the ground G by penetrating the retaining wall W using the casing pipe 20 by a known method. Then, as shown in FIG. 3, the anchor body 10 in the contracted state is inserted into the casing pipe 20 together with the tendon 12 and the supply hose 10I, and is installed at a predetermined position (the end of the casing pipe 20).

From the state shown in FIG.
4 and a fluid (indicated by an arrow F) is supplied into the anchor body 10 through a supply line 10I from a fluid supply source and a pressure supply means (not shown) as shown in FIG. Inflated state. Thereby, the anchor body 10
Exerts the supporting force or proof stress as an anchor.

When the fluid F is a liquid such as water and has a high fluidity, the expansion state of the anchor body 10 cannot be maintained while the supporting force or the proof stress as the anchor is exerted. In order to prevent the fluid F from flowing out of the anchor body 10, an unillustrated means (for example, closing an on-off valve provided in the supply line 10I) from the inside of the anchor body 10 to a ground side not shown is used. The path to the fluid source is closed.

Here, when the fluid F is relatively poor in fluidity such as earth and sand, there is a small possibility that the fluid F will flow out of the anchor body 10. The requirement for means for closing (from the ground to the unillustrated fluid source) is relatively modest.

Regardless of whether it is water or earth and sand, the content of the anchor body 10, ie, the injection material, is extremely inexpensive as compared with cement or mortar, and the construction cost can be kept low.

When it is no longer necessary to exert the supporting force or strength as an anchor due to the completion of the desired construction or other circumstances, the tendon 12 is first removed as shown in FIG. 5 or FIG.

FIG. 5 shows a case where the fluid F is a liquid (such as water).
When the path from the inside of the anchor body 10 to the fluid supply source (not shown) on the ground side is opened, the fluid F can be completely discharged to the outside of the anchor body 10 and the anchor body 10 is in a contracted state.

When the anchor body 10 is in the contracted state, it can be easily removed from the portion where the anchor has exhibited the supporting force or the proof strength in the expanded state. Therefore, unlike the conventional anchor body, it is completely prevented that it becomes a hindrance to post-construction after the necessity of exhibiting the supporting force or the proof stress is eliminated.

On the other hand, when the fluid F is earth and sand (FIG. 6), after the tendon 12 is removed, the anchor body 10 is buried in an expanded state. Here, since the anchor body 10 is made of woven fabric and earth and sand, it is integrated with the ground.
Therefore, it is possible to prevent the post-construction from being hindered as with the conventional cement or mortar. In addition, since it becomes integral with the ground after it is no longer necessary to exhibit the supporting force or the proof strength, in other words, it can be said that the anchor is "environmentally friendly".

Next, a second embodiment of the present invention will be described with reference to FIGS. Also in the second embodiment, the anchor is installed at a predetermined position using the casing pipe 20, and the basic procedure of installation and removal is shown in FIG.
-As shown in FIG.

FIG. 7 shows one process of installing the anchor body at a predetermined position. In FIG. 7, a casing pipe denoted by reference numeral 20 extends from the ground side to a location where the anchor body is to be installed. A rubber cover 22 is inserted into the casing pipe 20, and a rubber packer 24 is mounted inside the rubber cover 22.

The rubber cover 22 and the rubber packer 24 constitute a fixing member (corresponding to the anchor member in FIG. 1) which exhibits a supporting force or a proof strength. Here, although not explicitly shown in the drawings, a plurality of rubber packers 24 are provided.

A tendon 26 is wrapped around the rubber cover 22. In the embodiment shown in FIG.
Are wound three times. As the tendon 26, for example, a PC steel strand is used.

As shown in FIG. 8, the tendon 26 is fixed to a sheave portion 28 on the distal end side (the left side in FIG. 8). Is attached to a fixing member composed of a rubber cover 22 and a rubber packer 24.

As clearly shown in FIGS. 9 and 10, the sheave portion 28 includes the tip sheave 30 and the sheave cover 3.
2 are laminated. As particularly shown in FIG. 10, the tendons 26... Are sandwiched and mounted between the tip sheave 30 and the sheave cover 32.

Referring again to FIG. 8, the rubber packer 24 communicates with a supply line 24IM (main supply line), and an on-off valve 34 is interposed in the supply line 24IM. On the other hand, a secondary supply line 2 is connected to the rubber packer 24.
4IS is communicated, and an open / close valve 36 is interposed in the supply line 24IS. And the supply line 24IM,
The 24IS communicates with an unillustrated injection material supply means on the ground side.

As an injection material supplied to the rubber packer 24, water is used in the embodiment shown in FIGS.

Next, the construction procedure and operation of the embodiment shown in FIGS. 7 to 10 will be described. First, by a casing pipe excavating means (not shown), the casing pipe 20 is
Install from the ground side to the anchor anchorage point. This method itself is implemented by a conventionally known technique.

Next, as shown in FIG. 8, the rubber cover 22 containing the rubber packer 24 is attached to the casing pipe 20 with the sheave portion 28 and the tendons 26.
To move or guide to the anchor anchoring point. At this time, since the surface of the rubber cover 22 guided in the casing pipe 20 does not come into direct contact with the ground, the surface of the rubber cover 22 may be damaged by friction with the ground. Is prevented.

Rubber cover 2 containing rubber packer 24
2 is where the anchor is fixed, the rubber cover 22 containing the rubber packer 24 is located outside the casing pipe 20. In this state, high-pressure water is supplied to the rubber packer 24 from the high-pressure water supply means (not shown) on the ground side via the supply line 24IM. Then the rubber packer 24
Expands to a shape (for example, a shape similar to that shown in FIG. 1 or a cylindrical shape having a large radial dimension) that exerts an anchor supporting force or a proof stress, and the tendons 26. You can do it. Even if the rubber packer 24 expands, the rubber packer 24 is built in the rubber cover 22 and does not directly contact the ground. for that reason,
The rubber packer 24 is prevented from being damaged or broken due to friction with the ground at the time of expansion.

Then, only water is injected to exhibit the supporting force as the anchor, and it is not necessary to use cement, admixture, and the like. Therefore, there is no danger of leakage of cement milk at the time of injection, so that wastewater treatment and industrial waste treatment are not required.

The on-off valve 34 is closed to prevent the high pressure water from flowing out of the packer 24 so that the expanded state of the packer 24 cannot be maintained while the supporting force or the proof strength as the anchor is exerted. I do. Here, as described above, a plurality of rubber packers 2 are provided in the rubber cover 22.
4 is provided, even if one rubber packer 24 is damaged for any reason, the high-pressure water is supplied to the separate packer 24 via the supply line 24IS, and the separate packer 24 is inflated. It is possible to do.

When it is no longer necessary to exert the supporting force or the proof strength as an anchor due to completion of the desired construction or the like, the on-off valve 34 is opened, and the high-pressure water in the rubber packer 24 is supplied to the ground via the line 24IM. Then, the rubber packer 24 that has expanded is contracted. When the rubber packer 24 is in the contracted state, the sheave portion and the tendon are pulled to the ground side, so that the rubber cover 22 and the rubber packer 24 are guided in the casing pipe 20 and are easily removed from the anchor fixing portion. Therefore, the anchor body is completely removed after it is no longer necessary to exhibit the supporting force or the proof strength as the anchor, so that there is no obstacle to post-construction.

The removed rubber cover 22 and rubber packer 24 can be used again. In addition, sheave part 2
8 and tendons 26... Can also be reused.

The illustrated embodiment is merely an example, and does not limit the technical scope of the present invention. For example, the anchor body is not limited to the shape shown in FIG. 1 or the shape shown in FIG. 8, but it is also possible to adopt a conical anchor or an anchor having a plurality of continuous spheres. is there.

[0046]

The effects of the present invention are listed below. (1) An anchor fixing body exhibiting proof stress or bearing pressure can be formed without using cement or mortar. (2) There is no need for cement, admixtures, mixers, cement silos, etc., and no wastewater treatment facility or industrial waste treatment facility is required. (3) If the injection material to be injected into the anchor (or the rubber packer) is a liquid such as water, the liquid such as water is discharged from the anchor body when the anchor supporting force becomes unnecessary. The anchor is completely removed. (4) If the anchor body is made of a woven cloth and the injection material injected into the anchor is earth and sand or the like, after the anchor supporting force becomes unnecessary, the anchor is buried and killed to be integrated with the ground. . Therefore, there is no spontaneous destruction. (5) There is no possibility that the post-construction will be hindered by the presence of the anchor after use. (6) The fixing body (anchor body, or rubber cover and rubber packer) and tendon can be reused. (7) Bare wires can be used for removal anchors, so costs can be reduced. (8) When a casing pipe is used, a non-grease steel wire used as tendon can be used, so disposal is easy. (9) When a rubber cover and a rubber packer are used as the anchor body, since a plurality of rubber packers are provided, even if the expanding rubber packer is damaged, water is re-injected into another rubber packer. , Can be inflated. (10) There is no need to wait for solidification of the injected material (usually 3 days or more) necessary for normal tensioning of the ground anchor, and tensioning can be performed immediately after completion of anchor placement.

[Brief description of the drawings]

FIG. 1 is a side view showing a first embodiment of the present invention.

FIG. 2 is a view showing one step of anchor construction.

FIG. 3 is a view showing one step following the step of FIG. 2 in anchor installation.

FIG. 4 is a view showing one step following the step of FIG. 3 in anchor installation.

FIG. 5 is a diagram showing an example of a stage after it is no longer necessary to exert an anchor supporting force.

FIG. 6 is a view showing another example of the stage after the need to exert the anchor supporting force has been eliminated;

FIG. 7 is a cross-sectional view showing a second embodiment of the present invention.

FIG. 8 is a side sectional view showing a second embodiment.

FIG. 9 is a side view showing a tip sheave portion in the second embodiment.

FIG. 10 is an enlarged cross-sectional view illustrating an attached state of a tip sheave portion and a tendon.

FIG. 11 is a diagram showing an example of a conventional technique.

FIG. 12 is a diagram showing another related art different from FIG. 11;

[Explanation of symbols]

 10 anchor body 12, 26 ... tendon 12 is wound around. F: Fluid 10I, 24IM, 24IS: Supply line 14: Inlet 16: Seal member 20: Casing pipe 22: Rubber cover 24: Rubber packer 28: Sheave part 30 ・ ・ ・ Sheet at tip 32 ・ ・ ・ Sheave cover 34,36 ・ ・ ・ On-off valve

Continued on the front page (72) Inventor Fumio Kadota 1-6-4 Moto-Akasaka, Minato-ku, Tokyo F-term in Chemica Lugrout Co., Ltd. 2D041 GA03 GB03 GC03 GC06 GC14

Claims (6)

[Claims] The method includes the steps of: installing a anchor body that can be expanded by injecting an injectable material into an anchor anchoring position in a contracted state; and injecting the injectable material into the anchor body to expand it. An anchor construction method, wherein the anchor body is configured to have a surface that exerts a supporting force when inflated. 2. The anchoring method according to claim 1, wherein the injection material is a liquid, and a supply line for supplying the injection material liquid from the ground side into the anchor body is provided. 3. The anchoring method according to claim 1, wherein earth and sand are used as the injection material, and a supply line for supplying earth and sand from the ground side into the anchor body is provided. 4. A step of installing a casing pipe to an anchor anchoring position, and inserting the casing pipe into the casing pipe in a state where a tendon is wrapped around a cover made of a flexible material containing a plurality of packers made of a flexible material. A step of moving the cover with the tendon wrapped around to the anchor anchoring point, a step of positioning the cover outside the casing pipe at the anchor anchoring point, and a step of high-pressure water on the ground side through a high-pressure water supply line. A step of supplying high-pressure water into the packer from a supply unit to expand the packer. 5. A step of draining high-pressure water through a high-pressure water supply line to shrink the packer, and pulling the tendon wrapped around the cover to the ground side, so that the cover incorporating the packer is closed. 5. The method according to claim 4, further comprising the step of moving the anchor from a fixing position. 6. An anchor used in the anchoring method according to claim 1-5, wherein the anchor is constructed so as to be inflatable and contractible, and is connected to a line for injecting or discharging an injecting material, and exerts a bearing pressure when inflated. An anchor configured to have a shape having a surface.