JPH08144673A - Pre-boring method using auger - Google Patents

Abstract

PURPOSE: To easily excavate an embedding hole with high accuracy by performing a pre-boring. CONSTITUTION: An introducing pipe 10 for insertion of a spiral auger 5 is vertically movably provided in a scaffold 2 of a pile driving machine 1, on which the spiral auger 5 connected to a drive device 4 is mounted so as to be vertically movable. Before excavating an embedding hole for a pile or the like, the pipe 10 is lowered at a predetermined excavation site and the lower end thereof is forced into the ground to erect it and the spiral auger 5 is inserted into the pipe 10 so that an embedding hole is excavated using the pipe 10 as a guide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pre-boring method for excavating a buried hole with an auger when constructing a foundation pile or the like.

[0002]

2. Description of the Related Art In the construction of foundation piles and the like, a pre-boring method is often employed in which an excavation hole is formed by an auger and the foundation pile or the like is embedded in the hole. As shown in FIG. 4, this construction method generally includes a guide rail 3 provided on a yagler 2 of a pile driving machine 1 on which a drive device 4 can be raised and lowered, and a shake prevention tube 6 is provided on a lower portion of the yagler 2, The upper end of the spiral auger 5 which is inserted into the swing stop pipe 6 is connected to the drive device 4, and the spiral auger 5 is rotated and pushed into the ground for excavation.

In this case, the excavation must be properly cut at the position where the pile is buried. Therefore, conventionally, as shown in FIG. 5, a tubular panel 7 (shown by a chain line) having substantially the same diameter as the buried hole is placed on the ground, and powder 8 such as lime is scattered around the tubular panel 7 and then the tubular panel 7 is placed. The excavation site 9 is surrounded by the marking powder 8, and the excavation is started by aligning the tip 5a of the spiral auger 5 with the center of the excavation site 9.

[0004]

However, in practice, it is quite difficult to correctly align the tip 5a of the spiral auger 5 with the center of the excavation site 9, and misalignment often occurs. In addition, even if the centering is performed correctly, if the ground strength is uneven or there are stones, etc., misalignment often occurs, so that it is possible to correctly excavate the buried hole at a predetermined position. It is a difficult situation.

The present invention has been made to solve the above problems, and a guide pipe of a considerable length is erected at a predetermined position on the ground, and a spiral auger is inserted through the guide pipe to perform excavation. The purpose of the present invention is to make it possible to excavate a buried hole accurately and easily without complicated alignment.

[0006]

The structure of the present invention for achieving the above object will be described with reference to the drawings corresponding to the embodiments. The present invention relates to a yagura 2 of a pile driving machine 1,
A spiral auger 5 connected to the drive unit 4 and a guide pipe 10 through which the spiral auger 5 is inserted are provided so as to be vertically movable, and the guide pipe 10 is lowered to the ground in accordance with the excavation position of a buried hole such as a foundation pile. The bottom end of the spiral auger 5 is inserted into the guide pipe 10, and the guide pipe 10 is used as a guide for excavation.

[0007]

Before the excavation of the buried hole, the marking powder 8 is sprinkled around the predetermined excavation site 9. Induction tube 10 is powder 8
If you descend so that it can match the excavated area 9 surrounded by
The guide pipe (10) is erected by cutting into the ground by a blade-shaped portion (12) at its lower end. Then, when the spiral auger 5 is lowered, the tip end thereof is inserted into the guide tube 10, and the guide tube 10 serves as a guide to excavate and form a buried hole.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view showing a construction state according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view of the same part, and FIG. 3 is a perspective view of a spiral auger guide tube used in the present invention.

In the figure, 1 is a pile driver, 2 is a yagura of the pile driver 1, and 3 and 3 are a pair of guide rails. The guide rails 3, 3 are arranged in parallel in the vertical direction at a required interval and are connected to each other by a large number of connecting members 21, 21.
It is attached to one side of the yagura 2 via a large number of support members 22, 22 with a space from the yagura 2.

A drive device 4 is provided on the guide rails 3 and 3 so as to be vertically movable, and is attached to the wire rope 23.
It is adapted to be vertically moved along the guide rails 3 and 3 by pulling up and feeding out, and a spiral auger 5 which is rotated by the drive device 4 is suspended from the drive device 4. Further, a guide tube 10 through which the spiral auger 5 is inserted is provided on the guide rails 3 and 3 so as to be vertically movable.

The guide tube 10 is formed of a steel tube or the like so as to be vertically long, the upper end thereof is expanded into a trumpet shape 11 to facilitate the insertion of the spiral auger 5, and the lower end thereof is a blade portion 12.
Is formed. On the upper outer surface of the guide tube 10, the guide tube
Engaging members 13 for attaching the 10 to the guide rails 3 and 3 so as to be able to move up and down are projected.

The engaging member 13 is a pair of mounting plates 15 and 15 having an engaging groove 14 having a semicircular cross section, which circumscribes the guide rail 3.
It is formed by the connecting member 16 interposed between them, and the fastening bolts 17, 17 connecting the mounting plates 15, 15 and the connecting member 16. The distance between the mounting plates 15 and 15 can be slightly changed depending on the degree of tightening of the tightening bolts 17 and 17, whereby the joining pressure to the guide rail 3 can be adjusted.

A small ring 18 is provided at the upper end of the guide tube 10, and a wire rope 19 for raising and lowering the guide tube 10 is provided on this.
Terminals are combined. The wire rope 19 is stretched via a pulley 20 provided on the upper portion of the yagura 2, and the guide tube 10 is moved up and down along the guide rails 3 and 3 by pulling up and feeding it out.

The construction method of the present invention is carried out by using the pile driving machine 1 described above. When excavating a buried hole such as a foundation pile, as in the conventional case, a tubular panel 7 having a diameter substantially the same as that of the buried hole is placed on the ground at the excavation position as shown in FIG. After the powder 8 is sprayed and marked, the tubular panel 7 is removed, and the area surrounded by the powder 8 is defined as the excavation site 9. For the pile driver 1, the spiral auger 5 and the guide pipe 10 are pulled up and the guide pipe is
10 moves to a position corresponding to the excavated site 9.

Next, the wire rope 19 of the guide tube 10 is paid out to lower the guide tube 10 and the lower end of the guide tube 10 is cut into the excavation site 9. In this case, the lower end of the guide tube 10 is a blade portion 12 and the guide tube 10 has a considerable weight, so that the lower end thereof is a corresponding portion (5 to 10 cm) as shown in the figure.
It is set up by cutting into the ground. Even when the ground is hard, it is possible to surely make the guide pipe 10 bite if it is made to fall suddenly from a certain height.

After that, the wire rope 23 of the drive unit 4 is paid out and lowered, the tip of the spiral auger 5 is inserted into the guide tube 10, and the tip 5a thereof is grounded. In that state, if the spiral auger 5 is lowered while being rotated by the drive device 4, the excavation will proceed from the excavation site 9 surrounded by the guide pipe 10, and the excavation hole will be formed. At that time, since the screw auger 5 rotates and excavates by using the guide pipe 10 erected on the ground as a guide, it is not necessary to perform the complicated centering as in the conventional case, and the predetermined excavation site is surely dug down. be able to. After the formation of the excavation hole, the spiral auger 5 is pulled up, the guide pipe 10 is pulled up, the pile driver 1 is moved to the next excavation position, and the same work as above is repeated.

[0018]

As described above, according to the present invention,
When excavating a buried hole, a guide pipe through which a screw auger can be inserted is erected upright at the bottom of the excavation position, and the guide pipe is used as a guide for the screw auger. In addition, it is possible to easily and surely form a drill hole at a predetermined position without performing the troublesome work of aligning the tip of the screw auger. Further, misalignment of the screw auger due to variations in ground strength, etc. is prevented, and excavation can be performed accurately.

[Brief description of drawings]

FIG. 1 is a schematic view showing a construction state according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of the same main part.

FIG. 3 is a perspective view showing a guide tube of the spiral auger used in the present invention.

FIG. 4 is a schematic view showing a conventional construction technique.

FIG. 5 is an enlarged sectional view of the main part.

[Explanation of symbols]

 1 Pile driver 2 Yagura 3 Guide rail 4 Drive device 5 Spiral auger 6 Swing pipe 7 Tubular panel 8 Powder 9 Excavation site 10 Guide tube 12 Edge portion 13 Engaging member 14 Engaging groove 15 Mounting plate 16 Connecting member 17 Tightening Attached bolt 18 Annular body 19,23 Wire rope

Claims (1)

[Claims] Spiral auger connected to the driving device and a guide pipe through which the spiral auger is inserted are provided in the yagura of the pile driver so that they can be moved up and down, respectively, in accordance with the excavation position of the buried hole of the foundation pile, etc. A pre-boring method using an auger, which comprises lowering the bottom end of the auger to stand upright by digging into the ground, inserting a spiral auger into the guide pipe, and excavating using the guide pipe as a guide.