JPH0841872A - Anchorage device for anchoring front end of anchor - Google Patents

Abstract

PURPOSE:To prevent the slippage of an anchor body by providing an air reactor and a movable ring-shaped bag body to the front end of an anchor fixing body, and expanding the air reactor to pull out a casing after an anchorage section of the anchor body is inserted up to depth exceeding the casing. CONSTITUTION:An air reactor 20 is provided to the end of a screw shaft 5 of an anchor fixing body. A movable ring-shaped bag body 25 is provided to a main body 21 of the air reactor 20. The movable ring-shaped bag body 25 inserts an air injection section 26 in a mounting hole 22a of a flange 22 and is held with a flange section 24, a normal state before the air injection is formed in a gourd shape, and the largest diameter is smaller than an outside diameter of the flange 24. After that, in the case it is inserted in a casing B, the bag body 25 is inserted up to depth projected to a hole D side from the casing. Then, in the case the casing B is pulled out, when air is injected into the bag body 25, the bag body 25 is expanded to adhere the peripheral surface to the internal circumference of the hole D, a state of reaction force is made against pulling out of the casing B, and an anchor body is prevented from slipping out of the hole D.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device for a tip of an anchor during construction of an earth anchor.

[0002]

2. Description of the Related Art First, an example of conventional earth anchor construction using a packer system will be described with reference to FIG.

At the time of construction, a hole is drilled in the ground A, a casing B is inserted, a double pipe (not shown) is inserted into the casing B to feed water, and the earth and sand are drained out. After inserting an anchor body, which is provided with a packer 9 as a whole with a reference numeral 1A, at the boundary between the anchor fixing long portion La and the anchor free length portion Lf, the casing B is pulled out to expand the packer 9, and the anchor fixing long portion La is Then, the injection material C is injected to fix the anchor fixing member indicated by reference numeral 2A to the ground A. Therefore, the stranded wire 8 is tensioned and fixed with the anchor plate 10, the anchor head 11 and the wedge 12 while leaving the tension surplus portion Lo. Reference numeral 3 in the drawing is a lantern spacer, 4 is a bearing ring, 5 is a screw shaft, 6 is a cable, and 7
Is the setting pipe.

[0004]

In the construction of the earth anchor described above, since the casing B is pulled out while leaving the anchor body 1A, the anchor body 1A may slip down in the case of the upward anchor.

Further, when the ground A is bad, even if the injection material C is injected, the injection material C escapes from the tip.

It is an object of the present invention to provide a fixing device for an anchor tip which prevents the anchor body from sliding down and prevents the injection material from escaping.

[0007]

According to the present invention, an air reactor main body attached to the tip of an anchor fixing member, a flexible annular bag attached to the main body, and the flexible annular bag. And a means for supplying air to.

Further, according to the present invention, a plurality of locking pins are projected on the peripheral surface of the flexible annular bag body.

[0009]

In the fixing device of the anchor tip constructed as described above, the anchor body is inserted to such a depth that the anchor fixing portion exceeds the casing. Then, by expanding the air reactor and applying a reaction force to the ground to pull out the casing,
The anchor body is prevented from sliding down.

Therefore, the injected material is prevented from escaping from the tip to the ground.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. In these figures, parts corresponding to those in FIG. 4 are designated by the same reference numerals, and duplicated description will be omitted.

In FIG. 1, an air reactor generally designated by the numeral 20 is attached to the end of the screw shaft 5 of the anchor fixing member generally designated by the numeral 2.

Referring also to FIG. 2, the main body 21 of the air reactor 20 is screwed onto the screw shaft 5, and the flange portion 22 and the shaft portion 2 are joined together.
3 are formed, and the flange portion 22 is provided at the end of the shaft portion 23.
A flange portion 24 having the same diameter as that of is screwed. A flexible annular bag 25 is attached to the main body 21.

In its normal state, the bag body 25 has a gourd-like outer shape, the maximum diameter d1 of which is smaller than the outer diameter d of the flange portion 24, and an air injection portion 26 is provided on the threaded portion 5 side. . The insufflation unit 26 is connected to a compressed air source via a tube (not shown), and these members constitute an insufflation means. A plurality of locking pins 27 are provided on the outer peripheral surface of the bag body 25 so as to project therefrom.

Next, the operation will be described.

The flexible annular bag body 25 is inserted into the attachment hole 22a of the flange portion 22 through the air injection portion 26, mounted on the main body 21, and held by the flange portion 24.

At the time of insertion into the casing B, the bag body 25 is inserted to a depth H protruding from the casing B to the hole D side.

When the casing B is pulled up, air is supplied to the bag body 25 from a compressed air source through a tube. Then, the bag body 25 is inflated, the outer peripheral surface is brought into close contact with the inner peripheral surface of the hole D, the locking pin 27 bites, and a reaction force is exerted against the pulling out of the casing B. Therefore, even in the case of the upward anchor, the anchor body 1 is prevented from sliding down from the hole D.

At the time of injecting the injecting material, the packer 9 is expanded to inject the injecting material C between the packer 9 and the bag body 25, that is, in the anchor fixing long portion La. Therefore, the injection material C is prevented from escaping to the hole D side, and is reliably filled in the anchor fixing long portion La, and as a result, the anchor fixing long portion La is grounded.
Securely fixed to.

[0020]

Since the present invention is constructed as described above, it is possible to prevent the anchor body from sliding down due to the expansion of the air reactor and to prevent the injection material from escaping.

[Brief description of drawings]

FIG. 1 is a side view of an anchor body showing an embodiment of the present invention.

FIG. 2 is a side sectional view showing the air reactor of FIG.

FIG. 3 is a side sectional view showing the air reactor during expansion.

FIG. 4 is a side view showing an example of a conventional packer-type earth anchor.

[Explanation of symbols]

 A ... Ground B ... Casing C ... Pouring material D ... Hole La ... Anchor fixing length Lf ... Anchor free length Lo ... Tension extra length 1, 1A ...・ Anchor body 2, 2A ・ ・ ・ Anchor fixing body 3 ・ ・ ・ Lunch spacer 4 ・ ・ ・ Bearing ring 5 ・ ・ ・ Screw shaft 6 ・ ・ ・ Cable 7 ・ ・ ・ Setting pipe 8 ・ ・ ・ Stranded wire 9 ・..Packer 10 ... Anchor plate 11 ... Anchor head 12 ... Wedge 20 ... Air reactor 21 ... Main body 22, 24 ... Flange 23 ... Shaft 25 ... OK Flexible annular bag 26 ... Insufflation part 27 ... Locking pin

Claims (2)

[Claims] 1. An air reactor main body attached to a tip of an anchor fixing body, a flexible annular bag body attached to the main body, and an air feeding means to the flexible annular bag body. Anchor tip fixing device. 2. The anchor tip fixing device according to claim 1, wherein a plurality of locking pins are provided on a peripheral surface of the flexible annular bag body.