JPH0696847B2 - anchor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an anchor, and more particularly to an anchor that can fill a sheath with a hardening material without voids.

(Prior Art) Conventionally, an anchor as shown in FIG. 5 has been used.
That is, a plurality of tension members b are arranged in a deformed sheath a whose length is integrated, and further two injection pipes c and d are arranged. One injection pipe c opens in the deformed sheath a, and the other pipe d opens in the deformed sheath a.

The hardening material e is injected from both of the injection pipes c and d to fill the entire length inside and outside the deformed sheath a with the hardening material e to be hardened.

(Problems to be Solved by the Invention) The above-described conventional techniques have the following problems.

<B> The deformed sheath a and the injection pipe c are fixed by the water blocking material g at the deepest part of the deformed sheath a. The position may shift and the anchor may not work as designed.

<B> A polyethylene sheath or the like is used as the deformed sheath a, but the sheath a of the same material covers the outer circumference regardless of the free length portion and the fixing portion of the tension member b. Therefore, the strength of the fixing part, which requires strength, is not sufficient, and if the upper part of the free length is particularly corrosive, the conventional thin polyethylene sheath is not sufficient, and either way is insufficient, and halfway measures are taken. Often becomes.

<C> The problem that the deformed sheath a is a synthetic resin such as polyethylene is a problem of rigidity. A synthetic resin has low rigidity, and when pressure is applied to inject the hardening material e into the sheath a, it may lose the injection pressure and burst.

Further, the synthetic resin is soft to restrain the hardened material e inside, and the force to restrain the hardened material e is small. When the load acts to break the adhesion between the tensile material b and the hardened material e, the adhesion proof strength is drastically reduced.

The present invention has been made to solve the above problems, and an object thereof is to provide an anchor that can be placed in a drill hole as designed and that can be protected and fixed by a sheath of an appropriate material. To do.

(Means for Solving the Problems) In the anchor according to the present invention, the free length part sheath and the fixing part sheath are continuously arranged in the drilled hole. A polyethylene sheath is used as the free length sheath, and a steel deformed sheath is used as the anchor sheath.

The tension material inserted in the unbonded sheath is exposed in the fixing sheath. A waterproof material is filled in the joint between the free length sheath and the fixing sheath. This makes it possible to integrate the tension member and the fixing portion sheath.

The filling pipe inserted into the drilled hole from the surface of the earth is brought to the vicinity of the innermost portion of the fixing portion sheath.

Arrange the air vent pipe so as to pass through the waterproof material. At this time, the free length part sheath and the fixing part sheath communicate with each other. A plurality of air vent pipes can be arranged.

(Operation) The hardening material is filled from the filling pipe, and the air in the fixing portion sheath is discharged from the air vent pipe. When the hardening material is further filled, the hardening material filled in the fixing part sheath fills the free length part sheath through the air vent pipe.

A large pressure acts on the fixing sheath due to the pressure at the time of press-fitting the hardening material, but since the fixing sheath is a highly rigid steel sheath, it does not burst due to the pressure.

In addition, since the hardened material is constrained by the steel sheath with high rigidity, even if the tension material and the hardened material are cut off, the hardened material is firmly constrained by the steel sheath. Bind to prevent a large decrease in bond strength.

The hardened material also fills the free length sheath through the air vent pipe. The stiffener surrounds the tension material within the free length to prevent water from reaching and also to prevent the free length sheath from collapsing and cracking due to the pressure of the stiffening material injected outside.

Since the free length part sheath and the fixing part sheath are integrally fixed by the water blocking material, the sheath and the tension material are not displaced when being inserted into the drilled hole.

(Example) Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

In the figure, 1 is a free length part sheath, and 2 is a fixing part sheath. The free length sheath 1 uses a polyethylene sheath that is bendable to some extent, and the fixing sheath 2 is a deformed sheath made of steel and having irregularities formed around it. The free length part sheath 1 and the fixing part sheath 2 are continuously arranged in the drilled hole 3.

A plurality of tension members 4 are arranged in the free length sheath 1 and the fixing unit sheath 2, but the tension members 4 are inserted into the unbonded sheath 5 in the free length sheath 1 and then the fixing unit sheath 2 Let's expose it. As the tensile member 4, a stranded steel wire, a steel wire or the like can be used.

A filling pipe 6 is arranged from the surface of the earth in the free length part sheath 1 and the fixing part sheath 2 so that the filling pipe 6 reaches near the innermost part of the fixing part sheath 2.

A water blocking material 8 is filled in the connecting portion between the free length sheath 1 and the fixing portion sheath 2. Blown asphalt or epoxy resin can be used as the water blocking material 8. The water blocking material 8 fixes and integrates the tension material 4 and the sheaths 1 and 2. Therefore, the positional relationship between the tensile member 4 and the sheaths 1 and 2 will not be displaced in the subsequent work.

Before filling the water blocking material 8, the air vent pipe 7 is arranged in advance. The air vent pipe 7 is arranged so as to penetrate the water blocking member 8. As a result, the free length part sheath 1 and the fixing part sheath 2 may communicate with each other through the air vent pipe 7. A plurality of air vent pipes 7 can be arranged in the gap between the plurality of tension members 4 as shown in FIG.

In the state as described above, the hardening material 9 such as cement grout is filled through the filling pipe 6. Since the fixing portion sheath 2 is made of steel, the fixing portion sheath 2 does not burst even if the hardening material 9 is injected under high pressure. Therefore, the hardening material 9 fills the inside and outside of the fixing portion sheath 2 with a high pressure without any gap. Air and water in the fixing unit sheath 2 are discharged through the air vent pipe 7.

By further filling the hardening material 9, the hardening material 9 fills the free length part sheath 1 through the air vent pipe 7. At this time, even if the hardened material 9 is removed from the air vent pipe 7, a considerable pressure is applied to the fixing portion sheath 2 to push up the hardened material 9. However, since the fixing portion sheath 2 is a steel deformed sheath, it does not burst even when this pressure is applied. Therefore, the hardening material 9 can be injected without danger of the fixing sheath 2 rupturing even within a deeply drilled hole.

By blowing out the hardening material 9 from the surface opening of the free length sheath 1, it is possible to know that the hardening material 9 is filled in the fixing portion sheath 2. The pressure of the hardening material 9 which has come out from the tip of the fixing sheath is applied to the outside of the free length sheath 1, but it is balanced with the pressure of the hardening material 9 in the free length sheath 1 through the air vent pipe 7. This prevents the free length sheath 1 from being crushed. Further, the hardened material 9 surrounds the tensile member 4 so that even if the free length sheath 1 is cracked,
Prevent water from reaching.

When the load acts to break the adhesion between the tensile material and the hardened material,
The fixing portion sheath 2 made of steel having high rigidity firmly restrains the hardened material 9. Further, since the hardened material 9 strongly constrains the tensile material 4, the tensile material 4 is constrained by a force close to the adhesive force to obtain the adhesive strength, so that the adhesive strength is not significantly reduced.

(Effects of the Invention) Since the present invention has the configuration as described above, the following effects can be obtained.

<a> Since the tension material and the fixing portion sheath are integrated by the hardening material of the water blocking portion, the problem of the conventional construction method that the tension material and the sheath are displaced during the insertion work of the anchor into the drilled hole has been solved.

<B> By adopting a polyethylene sheath as the free length part sheath and a steel deformed sheath as the anchor part sheath, the anchor can be anchored and the prestressing force can be introduced appropriately. Further, since the expensive steel sheath is used only for the fixing portion, it is possible to prevent the cost from increasing.

<D> Since the deformed sheath made of steel having high rigidity is adopted as the fixing sheath, the sheath does not burst even when the hardening material is injected under high pressure.

<E> Since the steel sheath with high rigidity is used as the fixing sheath, even if the hardened material and the tensile material are no longer attached, the hardened material is restrained by the restraining force of the steel sheath. Bind to obtain adhesion strength close to adhesion strength. Therefore, the adhesive strength does not decrease sharply.

<F> The curing material is pushed up toward the ground through the narrow space outside the air vent pipe and the fixing sheath. Therefore, an extremely large pressure is applied to the hardening material injected into the fixing sheath, but since the fixing sheath is made of a steel material having high strength, it does not burst due to the internal pressure.

<G> The hardening material also fills the free length sheath through the air vent pipe. The outside of the free length sheath is filled with the hardening material that has come out from the tip of the fixing sheath, but since the hardening material also fills the inside of the free length sheath, it is in balance with the outside hardening material and is made of a relatively soft synthetic resin. The free length sheath is not crushed and there are no cracks or cracks. Therefore, the free length sheath does not pass water inside.

<H> Even if a crack is generated in the free length sheath, since the hardened material is filled inside, the water cannot easily reach the tensile material.

[Brief description of drawings]

1 and 2 are sectional views of an embodiment of the anchor according to the present invention, FIG. 3 are sectional views taken along the line AA of FIG. 2, FIG. 4 is an overall view of the anchor, and FIG. 5 is conventional. Sectional view of the example. 1 ... Free length part sheath, 2 ... Fixing part sheath, 3 ... Drilling hole, 4 ... Tensile material, 5 ... Unbonded sheath, 6 ... Filling pipe, 7 ... Air vent pipe, 8 ... Stop Water material, 9 ...
… Hardened material.

Claims (1)

[Claims] 1. A free length sheath made of a polyethylene sheath and a fixing part sheath made of a deformed steel sheath are continuously arranged in a hole, and a tension member inserted in an unbonded sheath is placed in the free length sheath. The tension material was exposed in the fixing part sheath, and the water blocking material was filled in the connection part of the free length part sheath and the fixing part sheath to fix and integrate the tension material and the fixing sheath, and it was inserted into the drilled hole from the ground surface. The filling pipe reaches near the innermost part of the fixing part sheath, and the air vent pipe penetrates the water blocking material to communicate the free length part sheath and the fixing part sheath, and both the free length part sheath and the fixing part sheath. Anchor filled with hardener.