JPH02279818A - Ground anchor assembly and ground anchor method - Google Patents

Abstract

PURPOSE:To obtain a sufficient 'covering' of a solidifiable material by winding a solidifiable material injection and positioning hose on the anchorage length range of a ground anchor built-up body having the solidifiable material and the anchorage length to provide. CONSTITUTION:It is constituted of a free length 4 coated with a sheath material 3 on the surface of an exposed anchorage length 2 of a tension steel material 1 and the tension steel material 1 and a positioning hose 5 to be wound on the whole length of the anchorage length 2, and a center line of the anchorage length 2 is corresponded with a center line of an excavated hole 6 inside the anchor excavated hole 6. An injection function of the anchorage solidifiable material 7 and a function to correspond the center line of the excavated hole 6 with the center line of the anchorage length 2 are given to the positioning hose 5. The end of the positioning hose 5 is fixed to the end of the anchorage length 2, and a spiral pitch of the hose 5 in the anchorage length 2 is decided with a hole diameter, etc. of the excavated hole 6. According to the constitution, a 'covering' of the solidifiable material in the anchorage length can be secured.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a ground anchor and a method for constructing the same, in which a ground anchor assembly can be fixed along substantially the center line of a drilled hole for the anchor.

<Conventional technology> Ground anchors are generally composed of tensile steel and a solidifying material such as cement milk, and are used for various purposes by transmitting the tension introduced into the tensile material from the solidifying material to the hole wall. .

By the way, in general, the yield strength of a ground anchor is greatly influenced by (1) the adhesion force between the tensile steel material and the consolidation material, and (2) the adhesion force between the consolidation material and the earth.

For this reason, in order to ensure a certain distance between the tensile steel material and the ground, an auxiliary tool called a spacer is currently installed in the middle of the tensile steel material.

<Problems to be Solved by the Present Invention> The conventional ground anchor technology described above has the following problems.

<A> When installing spacers and spacers, if the pitch is wide,
The middle part of the tensile steel bends and tends to approach the hole wall.

On the other hand, if the pitch of the spacers is narrowed, the number of spacers increases, which is not only uneconomical but also difficult to insert into the anchor hole.

<Opening> If the middle of the tensile steel material is abnormally close to the hole wall, sufficient "cover" by the consolidation material cannot be ensured.

If the cover, which also functions as a waterproof layer, is insufficient, water will seep in and corrode the tensile steel.

<C> If the middle of the tensile steel material approaches the hole wall abnormally and the covering is insufficient, the adhesion surface between the tensile steel material and the solidified material will drop, and the adhesion between the solidified material and the hole wall will be reduced. Since the adhesion strength decreases, the yield strength of the ground anchor decreases as a result.

OBJECT OF THE INVENTION The present invention was made to solve the above problems, and its purpose is to provide good corrosion resistance of tensile steel and sufficient ground anchor strength with a simple structure. An object of the present invention is to provide a ground anchor assembly and a ground anchor construction method that can secure the ground anchor assembly.

Configuration of the Present Invention> An embodiment of the present invention will be described below with reference to the drawings.

<A> Structure of ground anchor assembly FIG. 1 shows an example of a ground anchor sum body according to the present invention.

This ground anchor assembly consists of an exposed anchoring length part 2 of a tensile steel material 1, a free length part 4 whose surface is covered with a sheath material 3, and a positioning member wrapped around the entire length of the anchoring length part 2. It consists of hose 5.

Since the present invention has a structure in which the center line of the fixing length part 2 is approximately aligned with the center line of the anchor drilling hole 6 in the anchor hole 6, the fixing length part 2 is formed over the entire length of the anchor. Of course, the present invention can be applied to various types of ground anchor assemblies.

<Exposure> Tensile steel material Tensile steel material 1 is PC, iiQ line, P (Jal Yosu 49,
Known materials such as PC steel can be used.

<C> Positioning Hose The positioning hose 5 has both the function of injecting the fixing material 7 and the function (spacer function) of making the center lines of the anchor hole 6 and the fixing length portion 2 substantially coincide.

As the color fixing hose 5, a hollow hose made of flexible or stretchable resin or cloth can be used.

The positioning hose 5 can be attached by arranging the free length portion 4 linearly along either the inside or outside of the sheath material 3, as shown in FIG. 1.2.

The tip of the positioning hose 5 is fixed to the tip of the fixing length section 2 with tape or the like.

The diameter of the positioning hose 50 is selected so that it does not become an obstacle when inserting the ground anchor assembly into the anchor hole 6.

In addition, the screwing pitch of the positioning hose 5 in the anchoring length section 2 depends on the diameter of the PC and L wires, the hole diameter of the anchor hole 6, the subtype and installation angle of the ground anchor assembly, and the injection pressure of the consolidation material. Decisions will be made taking into account such factors.

Alternatively, a plurality of positioning hoses 5 may be used to wrap around the fixing length section 2.

<Construction Method> Next, the construction method of the ground anchor construction method will be explained using the case of a diagonal anchor as an example.

<A> Assembling and inserting the ground anchor assembly As shown in FIG.
Insert inside.

At this time, the positioning hose 5 is crushed.

It does not interfere with the insertion work of the ground anchor assembly.

FIG. 3 shows a cross-sectional view of the tip of the anchoring length section 2 when the ground anchor assembly has been inserted.

As seen in the figure, the anchoring length portion 2 is located below the center line of the anchor hole 6 due to its own weight before being filled with the consolidation material.

<Port> Filling with caking material Next, as shown in Fig. 4.5, caking material 7 such as cement milk is injected from the base end of the positioning hose S.

The consolidation material 7 passes through the positioning hose S and is discharged from the tip of the fixing length section 2.

When the consolidation material 7 passes through the positioning hose 5 wrapped around the fixing length section 2, the positioning hose 5, which had been collapsed until then, expands and lifts the tensile steel material 1 upward.

As a result, alignment is performed to the extent that the center line of the anchor length portion 2 approaches the center line of the anchor hole 6.

Therefore, by injecting the consolidation material 7, there are no places where the circumferential surface of the tensile steel material 1 in the anchor length portion 2 is extremely close to the hole wall of the anchor hole 6.

Since the positioning hose 5 is wound in a spiral manner, the flow of the consolidation material 7 within the anchor hole 6 is not obstructed.
It flows through the anchor hole 6 and penetrates into every corner of the hole wall, etc., between the positioning hose 5 and the tensile steel material 1.

This also applies when the ground anchor assembly is fixed vertically.

In addition, since the pressure inside and outside of the positioning hose 5 is equal, there is no fear that the positioning hose 5 will be crushed by injection of the consolidation material.

<C> Tension fixation Wait for the hardening of the consolidation material 7, and then apply tension from the base end of the ground anchor assembly to fix it using a known method.

<Other Embodiments> In the above embodiments, the positioning hose is used both for injecting the consolidation material and for positioning the ground anchor assembly. It can also be used only for positioning.

When the positioning hose is used for positioning the ground anchor assembly, it is necessary to separately provide a hose for injecting the consolidation material.

<Effects of the Present Invention> As explained above, the present invention has the positioning hose wrapped around the anchoring part of the ground anchor assembly so that the center line of the ground anchor assembly almost coincides with the center line of the anchor hole during grout injection. The following effects can be obtained because the positioning can be performed until the

<B> Sufficient "cover" of the consolidation material in the fixing length part can be ensured.

Therefore, it is possible to avoid a decrease in the strength of the ground anchor assembly.

<Exposure> Since a sufficient "cover" which also functions as a waterproof layer can be secured, high corrosion resistance of the tensile steel material can be obtained.

(kuha) There is no need to attach a large number of spacers as in the conventional method, and the operation of simply winding the hose is required, making it easy to assemble the ground anchor assembly.

<2> Since the injection work inside the positioning hose and the injection work inside the anchor hole can be performed at the same time, construction is easy and efficient.

[Brief explanation of drawings]

Fig. 1 2 Overall view of the ground anchor assembly according to the present invention Fig. 2; Cross-sectional view of the tip of the anchoring length when inserting the ground anchor assembly Fig. 3: Cross section of m = m in Fig. 2 Figure 4: Cross-sectional view of the tip of the fixing length part when injecting the consolidation material Figure 5: Cross-sectional view along v-■ in Figure 4

Claims (2)

[Claims] (1) In a ground anchor assembly having a fixing length section that is fixed together with a compacting material in a drilled hole for the anchor, a hose for injecting the compacting material and for positioning is wrapped and attached over the range of the fixing section. Features: Ground anchor assembly. (2) In the ground anchor construction method, in which the ground anchor assembly is inserted into the anchor hole, the anchor hole is filled with consolidation material, and the anchor is fixed under tension, the consolidation material is injected into the anchoring part of the ground anchor assembly. A ground anchor characterized by wrapping a hose for use and positioning around the ground anchor, and using the expansion pressure of the hose to move the center line of the fixed length of the ground anchor closer to the center line of the anchor hole when injecting the consolidation material. Construction method.