JPH06272247A - Joint unit with packer for permanent anchor - Google Patents

Abstract

PURPOSE:To block a fixing section without giving an influence by packer pressurization on a corrugate sheath by assembling a rubber packer on a joint sheath at the position apart from the fixing section. CONSTITUTION:A Pc steel product 14 is covered by a corrugate sheath 12 at the fixing section L1 of a permanent anchor 10, and a free length section L2 is covered by a plane sheath Opposite ends of the corrugate sheath 12 and the plane sheath are connected by a rigid joint sheath 18 such as a stainless pipe. A rubber packer 20 having a two-layer structure and capable of injecting an injection agent between an inner layer and an outer layer is assembled between the joint sheath 18 and an anchor hole 11. The injection agent is fed to the packer 20 to pressurize and expand it, and the fixing section L1 is blocked. The corrugate sheath 12 is separated from the packer 20 and is not affected by its pressurization, the corrugate sheath 12 low in height and thin in thickness can be used, and the diameter of the anchor hole 11 can be set to the required minimum value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint unit with a packer for a permanent anchor that uses a packer to close a fixing portion of the anchor.

[0002]

2. Description of the Related Art In a permanent anchor, it is necessary to secure reliability for a long period of time, and the durability of a tension material (usually PC stranded wire) is emphasized. Therefore, for example, a corrugated sheath made of a synthetic resin such as polyethylene is coated on the PC steel strand to isolate and protect the PC steel strand.

Since the corrugated corrugated (corrugated) shape has a large friction resistance, the load applied to the PC stranded wire is the ground of the anchor (wall of the anchor hole) via the corrugated sheath. It is reliably transmitted to the hole-drilling wall) to form the fixing portion.

Thus, the so-called double anticorrosion type permanent anchor, which is covered with a corrugated sheet, is waterproofed by a sealant, and the head cap is filled with anticorrosive oil, is excellent in corrosion resistance, Sufficient durability can be secured.

[0005] A grout such as cement paste, which has a large adhesive force with the PC steel strand, is pressed and injected into the anchor hole.

[0006]

As a general rule, the anchor
The anchorage area is set to a stable formation or a formation where grout adhesion strength can be expected. On the other hand, the free length part of the anchor is set to a soft formation or an unstable formation with many cracks.

When the grout is pressurized and injected into the anchor hole until it returns from the anchor hole through the gap between the outside of the corrugated sheath and the wall of the anchor hole, the anchor is injected.
A large amount of grout is wasted by injecting and infiltrating into the weak and unstable cracks in the free length.
Particularly, in a long anchor hole, a large amount of grout is injected into the free length portion, which is wasteful.

In order to effectively inject grout into the fixing portion while avoiding waste, a packer is generally used near the boundary between the fixing portion and the free length portion. The packer is made of cloth or rubber, and is placed outside the corrugated sheet at the free length side (anchor head side) by about 1 m from the boundary between the fixing portion and the free length portion.

The grout is pressurized and injected into the anchor hole inside the corrugated sheath (internal grout), and when it spreads over the anchor fixing portion, the outside of the corrugated sheath and the anchor hole wall are separated. Flows through the gap toward the anchor head (anchor hole inlet) (external grout).

An injecting agent (pressurizing liquid) such as air, water, cement milk, and foaming urethane is supplied into the packer to pressurize and expand the packer. Then, the pucker is deformed and brought into close contact with the corrugated sheet according to the corrugated shape and the shape of the anchor hole wall to cut off the escape route of the grout and close the fixing portion. Then, the pressure of the backflowed (outside) grout acts on the packer, and the pressure of the infusate of the packer fluctuates, so that it can be recognized that the grout reaches the fixing portion and reaches the packer.

Here, the grout is injected into the fixing portion while following the air in the anchor hole, and the air in the anchor is driven to the tip of the grout, that is, immediately below the packer. Therefore, when it is confirmed that the grout has reached the packer, the pressure applied to the packer is released. Then, the grout pushes out the infusate in the packer, dents the packer, and pushes air to flow back over the packer. When air is removed from the fuser via the packer, the infusate is reinjected into the packer.

When the packer swells to block the fixing portion,
The grout is sufficiently pressurized so that it can be injected into the fixing unit. As the grout is injected and filled in the fixing unit, the resistance of the grout to the pressure and the injection increases, and the situation of the pressure and the injection to the fixing unit can be easily grasped from the ground.
As described above, by using the packer, the pressurization and the injection of grout to the fixing unit can be managed while minimizing the waste of grout.

In the double rustproof permanent anchor, PC
The size of the space for inserting the steel stranded wire corresponds to the inner diameter of the corrugated sheath, and there is a wasted space between the anchor hole diameter (drilling diameter) and the inner diameter of the corrugated sheath. Therefore, if a corrugated sheath having a low height (corrugation height) and a thin thickness (wall thickness) is adopted, the anchor hole diameter can be minimized, which is economically advantageous.

However, the synthetic resin corrugated sheet is inferior in strength, and when the packer is pressurized and expanded, the corrugated sheet is damaged.
Before the packer is deformed and adheres to the corrugated shape of the tooth, it cannot withstand the pressure from the packer and
The waveform of the tooth may be crushed. And Korge
When the waveform of the tooth is crushed, the blocking effect of the packer is impaired, and pressurization and injection of grout to the fixing portion become insufficient.

SUMMARY OF THE INVENTION An object of the present invention is to provide a joint unit with a packer for a permanent anchor that can secure a sufficient blocking effect by blocking the fixing portion with a packer without crushing the corrugated sheet.

[0016]

In order to achieve this object, the joint unit of the present invention is provided with a rigid joint space such as a stainless steel pipe that can withstand the pressure from the packer, and At a position separated from the corrugated sheet, the fixing portion is closed by expanding the packer on the joint sheet.

The packer is composed of a two-layer rubber bag capable of injecting an injecting agent between the inner layer and the outer layer, and the outside of the packer is covered with a stretchable cloth cover to cover the expansion of the packer. Regulated.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 1, in a permanent anchor 10, a corrugated sheath 12 is provided at the anchoring portion L1 of the anchor, and a smooth space 16 (also called plane sheath) 16 is provided as a free length portion. L2
The corrugated sheet and the smooth sheet are connected by a joint pipe 18. The joint pipe 18 is constructed by attaching a packer 20 in advance, and
Together with this, a joint unit 22 is configured.

The corrugated sheath 12 is a polyethylene pipe as in the conventional case, and the smooth sheath 16 is, for example, a pipe of the same quality as the corrugated sheath, that is, a polyethylene pipe. . Also, joint pipe 18
Is a thin-walled pipe made of, for example, stainless steel having a strength capable of withstanding the pressure of the packer 20.

As will be described later, the smooth sheath 16 is directly attached to the joint pipe 18, but the corrugated sheath is used.
12 is attached to the joint pipe using a spiral spring 24.

Normally, the spiral spring 24 is formed in a shape having flat portions at both ends. However, in the embodiment, as can be seen from FIG. 2 in addition to FIG. It has a spiral free end 24a and a flat portion 24b at the other end.

The spiral free end 24a extends from the right end of the joint pipe 18, and the flat portion 24b of the spiral spring is fixed to the joint pipe at one end (the right end in the figure) of the joint pipe. For example, as shown in FIG. 2, the spiral spring 24 is spot-welded, but may be fixed by an adhesive or the like.

It is needless to say that the spiral spring 24 is selected so that it can be screwed into the corrugated sheet 12. Further, the joint pipe has an outer diameter slightly smaller than the inner diameter of the smooth pipe so that the smooth pipe 16 can be firmly attached to the joint pipe 18.

The smooth frame 16 is attached to the other end (left end in the figure) of the joint pipe 18, and as shown in FIGS. 2 and 3, in the embodiment, an annular projection 26 is formed on the left end of the joint pipe. Has been done. The protrusion 26 is preferably a curved surface in consideration of prevention of falling out after mounting and waterproofing. In such a configuration, the protrusions (curved protrusions) 26 are smooth and smooth.
It is in close contact with 16, and the joint pipe 18 and the smooth-sheath 16 are firmly connected to secure good water-stopping.

Further, a pair of annular protrusions (protrusions having curved surfaces) having the same shape as the protrusion 26 of the smooth-smooth are smooth-smooth.
The inner surface of 16 may be molded, and the projection 26 of the smooth frame may be sandwiched between these projections.

As shown in FIG. 3, if the slit 28 is provided at one end (right end) 16a of the smooth-sheath 16, the elastic force is smoothed.
By combining this slit with the protrusion 26, which is generated at the right end of the sushi, even better connection and water blocking can be obtained.

As can be seen from FIGS. 3 and 4 in addition to FIG. 2, the rubber ring 30 for sealing is closely attached and fixed to the joint pipe 18 at the anchor head side (left side in the figure). ing. A tube-shaped mounting port 32 is fixed to the rubber ring 30, and an injection liquid hose 33 (see FIG. 1) for injecting the injection liquid into the packer 20 is attached to the mounting port.

The rubber ring 30 is formed in a bulged shape only in the portion where the mounting port 32 is provided, in consideration of the economical efficiency of boring the anchor hole 11 (see FIG. 3).

The packer 18 is a two-layer rubber bag capable of injecting an injecting agent between the inner layer and the outer layer, and a cloth cover 34 covers the rubber packer. Then, each left end of the cover 34 and the packer 18 is fixed to the joint pipe 18 with a rubber ring 30 by a band 36 such as a steel band, a plastic band, a cloth band, and a wire. A steel band may be used as the band 36 in terms of durability.

As described above, the spiral spring 24 for connecting to the corrugated sheath 12 is provided at one end (the right end in the figure) of the joint pipe 18 on the anchor fixing portion L1 side, and the rubber packer 20 is provided. , Cover with a cloth cover 34, fix to the joint pipe 18, and attach the joint unit 22 with a packer.
Are configured.

According to the joint unit 22 with the packer, since necessary members are unitized, it is easy to carry the anchor construction to the site and store it at the site, and work at the site is required. Minimal, anchor
Construction work can be started quickly.

Further, since the packer is expanded between the joint pipe 18 capable of withstanding the strength of the packer 20 and the wall of the anchor hole 11, the corrugated sheet 12 of the fixing portion L1 is separated from the packer. And is not affected by the pressurization of the packer.

Therefore, the corrugated sheath 12 having a low height (corrugation height) and a thin thickness (wall thickness) can be adopted, and the diameter of the anchor hole is the minimum necessary, which is economical. Perforations are possible.

Further, without worrying about the deformation of the corrugated sheet 12, the packer 20 is pressurized to a high pressure, the fixing portion is firmly closed, and the grout is injected into the fixing portion under sufficient pressure to fill it. it can.

The joint unit 22 having the above structure is assembled, for example, as follows, and inserted into the anchor hole 11. First, the joint unit 22 is rotated, and the spiral spring 24 is turned on from the free end 24a side of the spiral spring.
It is screwed onto the tooth space 12.

Since the left end of the spiral spring is the flat portion 24b,
When the flat part of the spiral spring reaches the end face of the corrugated sheath,
The spiral spring 24 cannot be screwed any further and stops. Thus, the flat portion 24b of the spiral spring acts as a stopper for the corrugated sheath 12, and the end surface 12a of the corrugated sheath 12 and the flat portion 24b of the spiral spring are located at substantially the same position.

Then, the joint unit 22 is pushed in while covering the left end of the joint unit 22 with the smooth sheet 16, so that the smooth sheet is smoothed.
Attach the joint to the joint unit and combine it. Pickpocket 28,
The presence of the protrusions 26 allows the smooth-sheath 16 to be easily mounted and securely connected.

Here, if a male thread which can be screwed into the corrugated sheath 12 is cut into the joint pipe 18,
The processing cost is high, and the joint unit 22 and thus the anchor 10 are expensive. However, in this invention, the corrugated sheath 12 is attached to the spiral spring 24 fixed to the joint pipe 18.
The joint unit 22 can be obtained at low cost because it is only screwed to the.

Further, if a thread is cut on the joint pipe 18, the joint pipe must be made thicker by the amount corresponding to the cutting depth, the inner diameter of the joint pipe becomes smaller, and the effective diameter of the anchor hole 11 ( The insertable diameter of PC steel strand 14) is lost. In addition, thick joint pipe 18
Inevitably, the outer diameter of the joint pipe, and hence the diameter of the anchor hole 11, becomes large, which is uneconomical.

On the other hand, in the structure of the present invention in which the spiral spring 24 is fixed to the joint pipe 18, the inner diameter of the joint pipe can be set to a large value and no loss occurs in the effective diameter of the anchor hole. Further, it is not necessary to increase the thickness of the joint pipe 18 more than necessary, and the increase in the outer diameter of the joint pipe is suppressed as much as possible.

From the side of the free end 24a of the spiral spring, the spiral spring 24 is screwed onto the corrugated sheath 12. Since the left end of the spiral spring is the flat portion 24b, when the flat portion of the spiral spring reaches the left end (end surface) of the corrugated sheet, the spiral spring 24 can no longer be advanced and stops.

Then, the smooth-sheath 16 is mounted on the joint pipe 18 and pushed in until it abuts against the end face of the rubber ring 30, and the rubber ring serves as a smooth-smooth stopper. Since the projection 26 and the slot 28 are provided, the smooth attachment and connection of the smooth frame 16 to the joint pipe 18 is quick,
Can be done reliably.

In this way, the flat portion 24b of the spiral spring and the rubber ring 30 serve as stoppers so that the corrugated sheet 12 and the smooth sheet 16 can be accurately positioned with respect to the joint pipe 18, and the joint pipe 18 can be accurately positioned. The smooth and corrugated sheaths can be connected quickly and easily via the.

Then, the corrugated sheet 12 and the smooth sheet 16 are banded, and the corrugated sheet and the smooth sheet are fixed to the joint pipe 18, respectively, and the corrugated sheet, The smooth frame is firmly connected via the joint pipe.

After banding, for example, a heat shrink tu
Bubs are covered on the corrugated sheet 12 and the smooth sheet 16 respectively so as to cover the band. When heated, the heat-shrinkable tube shrinks and firmly adheres to the band 36, the corrugated sheet 12, and the smooth sheet 16 to stop the water at the connecting portion.

Instead of the heat shrinkable tube, a tape such as a cloth tape or a vinyl tape is wound on the band around the corrugated sheet 12 and the smooth sheet 16 and covered. Water may be secured at the connecting portion.

The corrugated sheath 12 is inferior in strength because of its shape. However, the spiral spring 24 has sufficient elastic force in the radial direction, and the spiral spring 24 has a corrugated sheet.
Since it becomes a reinforcing material for the belt, even if you tighten it firmly with a band,
In addition, even if the contraction force of the heat shrink tube acts, the corrugator
Toshisu does not transform.

Joint pipe of joint unit 22
After connecting the corrugated sheet 12 and the smooth sheet 16 to the end of 18, respectively, the hose 33 of the injection liquid is replaced with the rubber ring 30.
It is pushed into the upper hose attachment port and attached to the joint unit. In addition, PC steel material, for example, PC steel stranded wire 14
Is fixed to the tip of the corrugated sheet 12.

Then, with the corrugated sheet 12 first,
PC together with joint unit 22 and smooth-sheath 16
A steel strand 14 is inserted into the anchor hole 11 (see FIG. 1).
The PC steel stranded wire 14 is a partial ampoule in which the sheath 14a is covered with the free length portion L2.

After the PC steel stranded wire 14 is inserted into the anchor hole 11, the grout is reinforced with a smooth frame 16 and a corrugated frame 12.
It is pressurized and injected into the anchor hole 11 via.

In the embodiment, since the packer 20 is made of rubber, air, water or urethane having excellent fluidity can be used as the injecting liquid (pressurizing liquid), and the hose 33 has a small diameter. For example, a hose having an inner diameter of 4 mm and an outer diameter of 6 mm can be used. The hose 33 for the injection liquid is disposable, but since the hose having a small diameter is sufficient as described above, it is not necessary to unnecessarily increase the diameter of the anchor hole 11 and no economical loss occurs.

Also, air, water, urethane, etc.
1, the packer swells as indicated by the solid line in FIG. 1 and the alternate long and short dash line in FIG. 2, and closes the fixing portion L1 so as to cut off the escape route of the grout. As the joint pipe 18,
A material having a strength capable of withstanding the pressure from the packer 20 is selected, and the joint pipe is not deformed by the pressure of the packer 20 to impair the closing property.

When the grout is injected into the blocked fixing portion L1 and flows back through the gap between the outside of the corrugated sheath 12 and the wall of the anchor hole, and the pressure of the grout acts on the packer 20,
The pressure of the injection liquid in the packer fluctuates. Thereby,
It is recognized that the grout reached the packer 20 through the fixing section L1.

When the supply of the injection liquid to the packer 20 is released, the grout pushes the injection liquid out of the packer 20 and dents the packer because the injection liquid is air, water, urethane having excellent fluidity, or the like. No, it flows backwards over the packer. Then, the tip of the grout, that is, the air in the anchor hole 11 that has been driven right below the packer 20, is removed from the fixing portion L1.

When the grout flows backwards over the packer 20 and air is evacuated from the fixing section L1, the injecting liquid is supplied again to the packer, inflating the packer and closing the fixing section L1.

When the fixing portion L1 is closed by the packer 20 after bleeding air, the grout is sufficiently pressurized and injected, and the grout spreads under high pressure to the fixing portion. Then, the resistance of the grout to the pressure injection increases, and the pressure and the injection to the fixing portion can be easily controlled from the ground due to the fluctuation of the resistance.

Generally, a rubber packer does not have sufficient strength and continues to swell and burst even at a pressure of about 1 kg / square cm. However, in the embodiment, since the rubber cover 20 is covered with the cloth cover 34, the cloth cover serves as a reinforcing material,
The bulge of the rubber packer is restrained, and the packer can be expanded within the range of the strength of the cover while preventing the packer from bursting.
Therefore, it is not difficult to pressurize the packer 20 with a high pressure of about 3 kg / square cm, and the grout can be injected with a high pressure into the fixing portion L1 under the strong blockage by the high pressure packer.

Further, since the cloth cover 34 covers and protects the rubber packer 20, the packer is not exposed and damage to the packer is prevented. In the embodiment, the cloth cover 34 is provided separately from the rubber packer 20, but the cloth cover 34 may be integrally formed by coating the outer surface of the rubber packer with the cloth cover 34.

The known packer has a single-layer structure having no inner layer. In this structure, the pressure of the grout acts only on the outer surface of the packer, so that the packer is deformed inward in the radial direction and the anchor is formed. -A gap is likely to be formed between the hole and it is difficult to obtain sufficient clogging property.

On the other hand, in the present invention, the packer 20
Has a two-layer structure in which the injection liquid is injected between the inner layer and the outer layer, the pressure of the grout acts not only on the outer surface of the packer but also on the inner surface (the surface in contact with the joint sheath), and the inner radial direction , Try to deform the packer from both outside. However, in a structure in which pressure is applied from two opposite directions, a gap is unlikely to be formed between the anchor hole side and the joint sheath side with the packer 20, and sufficient closing performance can be secured.

In the embodiment, the smooth length is set to the free length portion L2.
16 are arranged. However, like the fixing portion L1, the free length portion L2 may be provided with a corrugated sheet. Fixing unit L
1. When the corrugated sheath is arranged on both the free length portion L2, the spiral spring 20 is fixed to both ends of the joint pipe 18.

The above-described embodiments are intended to explain the present invention, and do not limit the present invention at all, and all modifications and alterations made within the technical scope of the present invention are also included in the present invention. It goes without saying that it will be done.

[0064]

As described above, the permanent anchor of the present invention.
According to the joint unit with a packer, the corrugated sheet of the fixing portion is separated from the packer and is not affected by the pressure applied to the packer. Therefore, a corrugated sheath having a low height and a thin thickness can be adopted, the diameter of the anchor hole is the minimum necessary, and economical drilling is possible.

Further, without worrying about deformation of the corrugated sheet, the fixing part is firmly closed by pressurizing the packer to a high pressure, and the grout can be injected and filled into the fixing part under sufficient pressure.

Since the packer is made of rubber, air, water, foaming urethane or the like is used as an injection liquid, and a small diameter hose is used.
Since the spacer can be used, it is not necessary to unnecessarily increase the diameter of the anchor hole. Also, air can be removed from the anchor holes while minimizing grout waste.

Since the rubber packer is covered with the cloth cover, the cover serves as a reinforcing material to restrain the bulge of the packer and prevent the rubber packer from rupturing within the range of the strength of the cover. -Is inflated. Therefore, even though it is made of rubber, the packer can perform the closing action at high pressure,
Grout can be injected into the fixing section at high pressure.

Protected by a cloth cover, a rubber packer
Since the pad is not exposed, damage to the packer is prevented.

Further, since the necessary members are unitized, the transportation to the anchor construction site is easy, the work on the site is minimized, and the anchor construction can be started quickly.

If the corrugated sheath is screwed to the spiral spring, the corrugated sheath can be quickly and easily connected to the joint pipe.

Since the spiral spring serves as a reinforcing material for the corrugated sheet, the corrugated sheet and the smooth sheet can be firmly connected by banding.

The corrugated sheath is simply screwed to the inexpensive spiral spring without cutting the male screw, and the corrugated sheath can be inexpensively connected.

Further, since the corrugated sheath is screwed to the spiral spring fixed to the joint pipe, the inner diameter of the joint pipe can be set large and no loss occurs in the effective diameter of the anchor hole. Further, the outer diameter of the connecting portion does not become larger than necessary.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a double rust preventive type permanent anchor using a joint unit with a packer of the present invention.

FIG. 2 is a schematic front view of the joint unit of the present invention with the upper half section being a cross section.

FIG. 3 is an exploded perspective view of a joint unit.

FIG. 4 is a perspective view of a joint unit.

[Explanation of symbols]

 10 Double rust preventive permanent anchor 11 Anchor hole 12 Corrugated sheath 14 PC steel stranded wire (steel material) 16 Smooth-sheath 16a Smooth-succeed end surface 18 Joint pipe 20 (rubber) Packer -22 Joint unit 24 Spiral spring 30 Rubber ring 32 Hose mounting port 34 (Cloth) Cover 36 Band

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kiichi Hoashi 802-23 Shimizu, Noda City, Chiba Prefecture (72) Inventor Takehito Oshiba Togane City, Chiba 254-5 (72) Inventor Masayoshi Fukai Koto-ku, Tokyo Tosago 6-20-13-501 (72) Inventor Tadashi Yasui 3600, Amitsu, Kotomaki, Aichi Prefecture Oita Kitayama, Tokai Rubber Industry Co., Ltd.

Claims (3)

[Claims] 1. A ground anchor fixing portion covers a PC steel material with a corrugated sheath and a free length portion is pre-coated.
It is covered with a sheath, and the opposite ends of the corrugated sheath and the plain sheath are connected with a rigid joint sheath such as a stainless pipe, and a rubber joint is used between the joint sheath and the anchor hole. Packer
A joint unit with a packer for permanent anchors. 2. The ground anchor fixing portion covers the PC steel material with a corrugated sheath and the free length portion is pre-coated.
It is covered with a sheath, and the opposite ends of the corrugated sheath and the plain sheath are connected with a rigid joint sheath such as a stainless pipe, and a rubber joint is used between the joint sheath and the anchor hole. Packer
The packer is a rubber bag with a two-layer structure that can inject the injectable agent between the inner layer and the outer layer. The stretchable cloth cover covers the outside of the packer and the expansion of the packer is regulated by the cover. A joint unit with a packer for permanent anchors. 3. A spiral spring for connection with a corrugated sheath is provided at one end of a joint pipe on the anchor portion side of the anchor, and the spiral spring for coupling has a spiral free end on the corrugated sheath side. A pack for a permanent anchor according to claim 1 or 2, wherein the smooth side has a flat end.
With joint unit.