JPH0378893B2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to an anchor construction method.

<Prior Art> As one of the anchor construction techniques, there is a construction method shown in FIG. 7.

In this construction technique, a rigid mortar cone E is first formed by filling a solidifying material such as mortar into a sheath material C that covers a portion of an anchor steel material B to be anchored.

The anchor hole A is filled with a fixing material F such as concrete or mortar in advance.

Then, a mortar cone E is driven into the anchor hole A and buried therein, thereby pressing the fixing material F onto the surrounding ground.

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

(1) In order to drive the mortar cone E into the fixing material F in the anchor hole A, a press-fitting device such as an air hammer or jack is required.

(2) Since the mortar cone E is driven after hardening, a crane or scaffolding is required to support the mortar cone E.

(3) The longer the total length of the mortar cone E, the greater the design strength of the anchor.

However, in consideration of actual workability, if there is an obstacle above the anchor hole A and the working space is restricted, construction becomes difficult, and the total length of the mortar cone E is limited.

(4) It takes a long time to complete the construction of the anchor.

<Objective of the present invention> The present invention has been made in order to solve the above-mentioned problems, and provides excellent workability and a high anchor effect. The purpose is to provide anchor construction methods.

<Example> Hereinafter, an example of the anchor construction method according to the present invention will be described with reference to the drawings.

<A> Structure of anchor cable (Fig. 1) 1 is an unbonded type anchor tension material in which a polyethylene sheath material is coated around the PC steel wire, etc., and anti-rust treatment is applied by sealing grease etc. inside. It is.

Reference numeral 2 denotes a corrugated sheath made of a flexible material made of steel, synthetic resin, or the like, and the peripheral surface of which is molded into an uneven shape.

A conical cap 21 is attached to the distal opening of the corrugated sheath 2.

The corrugated sheath 2 is longer than the entire length of the anchor hole A.

<B> Construction method [Filling the solidifying material into the anchor hole] (Fig. 2) An external solidifying material 5 such as concrete or mortar is filled into the anchor hole A made in a predetermined ground up to a predetermined position h1.

[Inserting into the anchor hole] (FIG. 3) Insert the grout hose 4 and the anchor tension member 1 deep into the corrugated sheath 2, and then position the tip of the corrugated sheath 2 directly above the anchor hole A.

[Filling with internal solidifying material] The anchor tensile material 1 and the corrugated sheath 2 are successively built into the anchor hole while filling the internal solidifying material 3 such as mortar or resin into the corrugated sheath 2 via the grout hose 4.

The above operations are performed before the external hardening material 5 hardens.

[Relationship between internal solidifying material and external solidifying material] The filling level h2 of the internal solidifying material 3 that is finally filled into the corrugated sheath 2 is determined by the filling level h2 of the internal solidifying material 3 that is finally filled into the corrugated sheath 2, as shown in FIG. Until it reaches a position higher than the filling level h1.

In the present invention, when inserting the corrugated sheath 2 into which the anchor tensile material 1 is inserted into the anchor hole A, it is possible to easily insert the corrugated sheath 2 into the anchor hole A without using a conventional air hammer or jacking device.

This is due to the relative pressure difference between the internal solidifying material 3 filled in the corrugated sheath 2 and the external solidifying material 5 filled in the anchor hole A. In short, it is sufficient that the entire weight of the corrugated sheath 2 including the uncured internal solidifying material 3 is higher than the buoyant force due to the external solidifying material 5 in the anchor hole A.

That is, as shown in FIG.
Comparing the internal pressure of the internal solidifying material 3 within the corrugated sheath 2 with the internal pressure of the internal solidifying material 3 within the corrugated sheath 2 reveals that the internal pressure of the internal solidifying material 3 within the corrugated sheath 2 is high.

As a result of the internal pressure of the corrugated sheath 2 being maintained higher than the pressure within the anchor hole A over the entire length of the anchor tension member 1, "apparent rigidity" is generated in the anchor cable.

Furthermore, since the amount of internal solidifying material 3 filled in the sheath 2 increases compared to the conventional construction method, the weight of the anchor cable increases accordingly, making it easier to insert it into the anchor hole A. .

Therefore, by pressurizing and filling the internal solidifying material 3 into the corrugated sheath 2, it is also possible to enhance the "apparent rigidity".

Finally, the corrugated sheath 2 and anchor tension material 1 protruding to the ground side are cut to complete the anchor fixing work. (FIG. 4) It goes without saying that even if the corrugated sheath 2 is made of a rigid material, it can be inserted into the anchor hole A without using a press-fitting device.

<Other Examples> As another method for making the entire weight of the corrugated sheath 2 including the internal solidifying material 3 higher than the buoyancy due to the external solidifying material 5 in the anchor hole A, the internal solidifying material 3 and the external solidifying material 5 are each There is a method of using materials with different specific gravities.

As a method of generating a difference in specific gravity between the internal solidifying material 5 and the external solidifying material 5, for example, adding an additive with a large specific gravity such as iron powder to the mortar constituting the internal solidifying material 3, or One possible method is to mix lightweight sand or the like with low specific gravity.

<Effects> As described above, according to the present invention, the sheath material is inserted into the anchor hole while maintaining the overall weight higher than the buoyancy caused by the solidifying material in the anchor hole, so that the following effects can be obtained.

<B> The anchor can be inserted without using an air hammer or jacking device as in conventional anchor insertion techniques.

<B> Since "apparent rigidity" can be imparted to the sheath, the sheath becomes difficult to bend and the anchor insertion work becomes easier.

<C> The internal solidifying material is separated from the external solidifying material by a corrugated sheath.

Therefore, the quality of the internal solidification material can be adequately controlled.

As a result, the friction strength between the anchor tensile material and the solidified material is improved.

<D> Since the internal pressure of the corrugated sheath is greater than the pressure within the anchor hole, when the corrugated sheath is inserted into the external solidifying material within the anchor hole, the external solidifying material is strongly pressed against the surrounding hole wall.

Therefore, an excellent anchor effect can be expected.

<E> If the corrugated sheath is made of a flexible material, the anchor cable can be installed in the anchor hole without using a hanging crane or scaffolding.

In particular, even if the work space is restricted due to an obstacle located above the anchor hole, construction can be carried out without being restricted by the length of the anchor cable to be inserted.

<F> Since the anchor tensile material inserted into the anchor hole uses a corrugated sheath material over the entire length of the cable, a high rust prevention effect can be obtained.

[Brief explanation of drawings]

Figure 1: An explanatory cross-sectional view showing the creation of the anchor, Figures 2 to 4: An explanatory diagram of the construction method, Figures 5 and 6: An explanatory diagram comparing the pressure in the anchor hole and the internal pressure of the corrugated sheath, Figure 7. : Explanatory diagram of conventional technology. 1: anchor tensile material, 2: corrugated sheath, 3: internal solidifying material, 5: external solidifying material, A: anchor hole.

Claims (1)

[Claims] 1. An anchor construction method in which an anchor is inserted and fixed in an uncured solidified material filled in an anchor hole, the anchor tensile material being attached to a bottomed sheath material having a corrugated peripheral surface. and filling the sheath material with the solidifying material, the sheath material is inserted into the anchor hole in a state in which the entire weight of the sheath material including the uncured solidifying material is higher than the buoyancy due to the solidifying material in the anchor hole. Anchor construction method.