JP3563133B2 - Pre-boring method by auger - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a pre-boring method for digging a burial hole with an auger when constructing a foundation pile or the like.
[0002]
[Prior art]
In the construction of foundation piles and the like, a preboring method of forming a drilling hole with an auger and burying the foundation pile and the like in the hole is often used. In this method, generally, as shown in FIG. 4, a driving device 4 is provided on a guide rail 3 provided on a yagler 2 of a pile driving machine 1 so as to be able to move up and down, and a vibration-preventing pipe 6 is provided at a lower portion of the yagler 2. The upper end of the spiral auger 5 that is inserted through the vibration-prevention pipe 6 is connected to the drive unit 4, and the spiral auger 5 is pushed into the ground while rotating to perform excavation.
[0003]
In this case, the excavation must be properly ground at the position where the pile will be buried. Conventionally, as shown in FIG. 5, a tubular panel 7 (indicated by a dashed line) having substantially the same diameter as the buried hole is placed on the ground, and powder 8 such as lime is sprayed around the tubular panel 7. The excavation is started by setting the tip 5a of the spiral auger 5 to the center of the excavation site 9 in the area surrounded by the marking powder 8.
[0004]
[Problems to be solved by the invention]
However, in practice, it is very difficult to correctly align the tip 5a of the spiral auger 5 with the center of the excavation site 9, so that misalignment often occurs. In addition, even when the alignment is performed correctly, if the strength of the ground is uneven or there is a stone or the like, misalignment often occurs, so that it is necessary to excavate the buried hole correctly at a predetermined position. It is a difficult situation.
[0005]
The present invention has been made in order to solve the above-mentioned problem, and a guide tube of a considerable length is erected at a predetermined position on the ground, and a spiral auger is inserted into the guide tube to perform excavation, which is troublesome. It is an object of the present invention to easily and accurately excavate a buried hole without performing centering.
[0006]
[Means for Solving the Problems]
The configuration of the present invention for achieving the above object will be described with reference to the drawings corresponding to the embodiments. The present invention provides a spiral auger 5 connected to a driving device 4 on a yagler 2 of a pile driver 1. Guide pipes 10 formed vertically long to penetrate the spiral auger 5 are provided so as to be able to move up and down, and a tubular panel 7 having substantially the same diameter as the burial hole is placed on the ground at the excavation position, and markings 8 are formed around the panel. After that, the tubular panel 7 is removed, the spiral auger 5 and the guide tube 10 are pulled up , the pile driving machine 1 is moved to a position where the guide tube 10 matches the excavation site, and the guide tube 10 is lowered. After the lower end of the spiral auger 5 is erected, the spiral auger 5 is lowered and inserted into the guide tube 10, and excavation is performed using the guide tube 10 as a guide.
[0007]
[Action]
Prior to excavation of a burial hole, a marking powder 8 is sprayed around a predetermined excavation site 9. When the guide tube 10 is lowered so as to be able to match the excavation site 9 surrounded by the powder 8, the guide tube 10 is cut into the ground by the blade-shaped portion 12 at the lower end thereof and stands upright. Then, when the spiral auger 5 is lowered, the tip is inserted into the guide tube 10 and the guide tube 10 serves as a guide to excavate and form a buried hole.
[0008]
【Example】
Hereinafter, embodiments of the present invention will be described 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 essential part, and FIG. 3 is a perspective view of a guide tube of a spiral auger used in the present invention.
[0009]
In the drawing, reference numeral 1 denotes a pile driver, 2 denotes a yagler of the pile driver 1, and 3 and 3 denote a pair of guide rails. The guide rails 3 and 3 are arranged in a vertical direction at a required interval, and are connected to each other by a large number of connecting members 21 and 21. It is attached via 22,22.
[0010]
A drive device 4 is provided on the guide rails 3, 3 so as to be able to move up and down. The wire rope 23 attached to the guide rails 3, 3 is lifted and extended to be adjusted up and down along the guide rails 3, 3. A spiral auger 5 that is rotated by the driving device 4 is suspended from the device 4. 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 able to move up and down.
[0011]
The guide tube 10 is formed to be vertically long by a steel tube or the like, and the upper end thereof is expanded in a trumpet shape 11 to facilitate insertion of the spiral auger 5, and the lower end is formed in the blade-shaped portion 12. An engagement member 13 for projecting the guide tube 10 to the guide rails 3 and 3 so as to be able to move up and down is protruded from an upper outer surface of the guide tube 10.
[0012]
The engaging member 13 includes a pair of mounting plates 15, 15 having an engaging groove 14 having a semicircular cross section circumscribing the guide rail 3, a connecting member 16 interposed therebetween, and the mounting plates 15, 15. It is formed by fastening bolts 17, 17 for connecting to the connection member 16. The distance between the mounting plates 15, 15 can be slightly changed depending on the degree of tightening of the tightening bolts 17, 17, so that the joining pressure to the guide rail 3 can be adjusted.
[0013]
A small ring 18 protrudes from the upper end of the guide tube 10, and a terminal of a wire rope 19 for moving the guide tube 10 up and down is connected to the small ring 18. The wire rope 19 is stretched via a pulley 20 provided on the upper part of the yagrel 2, and the guide tube 10 is moved up and down along the guide rails 3 and 3 by pulling up and extending the wire rope 19.
[0014]
The construction method of the present invention is carried out using the above-described pile driver 1. When excavating a buried hole such as a foundation pile, as shown in FIG. 5, a tubular panel 7 having substantially the same diameter as the buried hole is placed on the ground at the excavation position, and lime or the like is placed around the excavated hole. 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 an excavation site 9. In addition, the pile driver 1 moves to a position where the guide tube 10 matches the excavation site 9 with the spiral auger 5 and the guide tube 10 pulled up.
[0015]
Next, the wire rope 19 of the guide pipe 10 is extended to lower the guide pipe 10, and the lower end of the guide pipe 10 is cut into the excavation site 9. In this case, the lower end of the guide tube 10 is a blade-shaped portion 12 and the guide tube 10 has a considerable weight. It will be erected. Even when the ground is hard, the guide tube 10 can be surely cut into the ground if the guide tube 10 is suddenly dropped from a certain height.
[0017]
Thereafter, the wire rope 23 at the drive position 4 is extended and lowered, and the tip of the spiral auger 5 is inserted into the guide tube 10 to ground the tip 5a. If the spiral auger 5 is lowered by rotating the spiral auger 5 by the driving device 4 in this state, the excavation proceeds from the excavation site 9 surrounded by the guide tube 10 and a drill hole is formed. At this time, since the spiral auger 5 rotates and excavates using the guide pipe 10 erected on the ground as a guide, it is not necessary to perform complicated centering as in the related art, 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 and the guide tube 10 is pulled up, the pile driver 1 is moved to the next excavation position, and the same operation as described above is repeated.
[0018]
【The invention's effect】
As described above, according to the present invention, when excavating a buried hole, a guide tube through which a spiral auger can be inserted is erected with its lower end biting into the ground at the excavation position, and the guide tube is guided by the spiral auger . Since the excavation is performed as described above, the excavation hole can be easily and reliably formed at a predetermined position without performing the complicated work of centering the tip of the spiral auger as in the related art. In addition, misalignment of the spiral auger due to variation in ground strength or the like is prevented, and excavation can be performed with high accuracy.
[Brief description of 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 main part.
FIG. 3 is a perspective view showing a guide tube of a 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]
DESCRIPTION OF SYMBOLS 1 Pile driver 2 Yagra 3 Guide rail 4 Drive device 5 Spiral auger 6 Shock pipe 7 Tubular panel 8 Powder 9 Excavation ground 10 Guide pipe 12 Blade shape 13 Engaging member 14 Engaging groove 15 Mounting plate 16 Connecting member 17 Tightening Bolts 18 Rings 19, 23 Wire rope

Claims (1)

A scaffold of pile driver, a vertically elongated guide tube for inserting the spiral auger and said spiral auger connected to the drive unit, respectively vertically movably provided, tubular substantially the same diameter as the burying holes in ground drilling site After placing the pile and marking around it, remove the tubular panel, lift the spiral auger and guide tube, and move the pile driver to a position where the guide tube matches the excavation site Pre-boring in an auger characterized by lowering the guide pipe, cutting the lower end thereof into the ground, standing upright, lowering the spiral auger, inserting the spiral auger into the guide pipe, and excavating using the guide pipe as a guide. Construction method.

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