JPH0558084B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for constructing an earth anchor in the ground.

(Prior Art) Various methods of constructing earth anchors that involve grout injection are known in the art, but usually the ground is first excavated, and then a core material is charged into the hole and grout is injected.

However, this method was inefficient because the process involved two steps: excavation and grout injection.

(Problems to be Solved by the Invention) The present invention aims to solve the above-mentioned conventional problems and provide a method for constructing an earth anchor with very high construction efficiency.

(Example) The method for constructing an earth anchor of the present invention (hereinafter referred to as the construction method of the present invention) will be described below with reference to Examples shown in the drawings.

FIG. 1 shows the construction method of the present invention, which uses a core pipe 1 made of a steel pipe or the like.

A tip bit 2 is fixed to the tip of the core pipe 1, and the tip bit 2 has a flange portion 4 that projects laterally.

Further, a cavity 3 is provided within the tip bit 2, and the cavity 3 communicates with the core pipe 1.

On the other hand, the flange 4 is provided with a hole 5 that opens upward, and the hole 5 communicates with the cavity 3.

The core pipe 1 to which the tip bit 2 is fixed is driven into the ground G by being hit, rotated, etc. by a driving device (not shown).

At the same time as this driving, grout 9 is injected into the core pipe 1.

The grout 9 flows from the core pipe 1 through the cavity 3 and hole 5 of the tip bit 2 into the borehole 7 formed by the tip bit 2.

That is, the gap between the drilled hole 7 formed by the tip bit 2 and the core pipe 1 is filled with grout 9 at the same time.

In order to prevent the grout 9 from overflowing onto the ground G, a cover 8 is attached to the upper end opening of the drilled hole 7 in the illustrated embodiment.

With the core pipe 1 driven to a predetermined depth, the core pipe 1 and the tip bit 2 are left in the ground G as they are.

As a result, the grout 9 hardens using the core pipe 1 as a reinforcing bar, and becomes an earth anchor A as shown in FIG. 2 or 3.

FIG. 4 shows an example of a driving device for implementing the construction method of the present invention, and the driving device 11 has a main body 12 equipped with a hammer 15 that applies impact, rotation, etc. to the core pipe 1.

The main body 12 can be tilted at any angle by the cylinder 14.

In addition, the core pipe 1 is connected to the injection pump 16 by the hose 6.
The injection pump 16 pumps out the grout in the mixer 17.

FIG. 5 shows another core pipe and tip bit used in the construction method of the present invention, which have the following features compared to those in FIG.

That is, the hole 5 for injecting the grout 9 is provided in the peripheral wall near the tip of the core pipe 1 (near the tip bit 2).

Further, the top of the tip bit 2 is formed with multiple peaks, and a flange material 20 (the one shown is a bar material wound in a linear shape) is attached to the outer peripheral surface of the core pipe 1.

The flange material 20 restrains the movement of the grout 9 in the axial direction within the drilled hole 7 and improves the penetration pressure of the grout 9 into the ground G when using an expandable grout 9 containing expandable cement or the like. It is.

FIG. 6 shows another core pipe used in the construction method of the present invention, which has a flange material 20 on its outer peripheral surface that has a different shape compared to that of FIG.

Furthermore, a plurality of core pipes 1 are used by being connected by a coupler 21 (threaded).

(Effects of the Invention) The embodiments of the earth anchor construction method of the present invention are as described above, and the effects thereof are listed below.

(1) The construction method of the present invention has the structure described in the claims, and in particular, since the grout is injected at the same time as the core pipe is driven, the process is performed only in one time, and the construction efficiency is very high.

(2) The construction method of the present invention has the same configuration as above, and in particular, since the core pipe itself is used as a reinforcing bar, there is no need for any effort to pull it out.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing the construction method of the present invention, Figs. 2 and 3 are longitudinal sectional views of the earth anchor constructed as above, and Fig. 4 is a driving device for implementing the above construction method. A side view showing an example, Fig. 5 is a partially cutaway front view showing another core pipe and tip bit used in the same construction method, and Fig. 6 is a partially cutaway front view showing another core pipe used in the same construction method. Front view. 1... core pipe, 2... tip bit, 3... void, 4... flange, 5... hole, 6... hose, 7...
...Drilling, 8...Cover, 9...Growing, 11...
Driving device, 12...Main body, 13...Base, 14...
... cylinder, 15 ... hammer, 16 ... injection pump, 17 ... mixer, 18 ... cement,
19...Power source, 20...Tsuba material, 21...Katsu puller, A...Earth anchor, G...Ground.

Claims (1)

[Claims] 1. A core pipe with a tip bit having a side protruding flange fixed to its tip and a hole provided at or near the tip bit is driven into the ground, and at the same time, grout is poured from the core pipe through the hole. An earth anchor construction method in which grout is injected into the hole formed by the tip bit, and then the core pipe is left as is and the grout is hardened as a reinforcing bar.