JPH0726393B2 - Pile pulling device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device used for pulling out existing piles.

[0002]

2. Description of the Related Art It is sometimes necessary to demolish an old building and remove an existing foundation pile of the old building in order to build a new building in the same place.

Conventionally, various methods have been proposed for removing the existing foundation piles reliably without damaging the piles, as disclosed in Japanese Patent Laid-Open Nos. 58-54127 and 58-58.
191819, JP60-138116, JP61-922
No. 14 and Japanese Patent Laid-Open No. 63-147013.

Japanese Patent Laid-Open No. 58-54127, in particular, drives in a cylindrical casing provided with a water discharge port that opens inward and a mechanism that holds the pile by holding it when it is pulled up. There is disclosed a method of excavating the outer circumference of a pile and operating a pile holding mechanism when pulling up the casing of the pile to pull up the driven pile while holding the pile.

This construction method has the advantage that the piles can be pulled out efficiently, and even with multiple piles, all the piles can be pulled out in one operation.

However, when the direction in which the driving force transmitted by the rotary drive device acts is slightly deviated or the soil is uneven, the excavation direction is biased and the inner surface of the casing comes into contact with the driving piles, and the work is delayed. The problem remains.

[0007]

SUMMARY OF THE INVENTION The present invention is disclosed in the above-mentioned JP-A-58.
In order to fully exert the advantages of the construction method disclosed in Japanese Patent Laid-Open No. 54127, there is to find a method for maintaining a constant excavation direction by a casing.

[0008]

Means for Solving the Problems The present invention, as means for achieving the above-mentioned object, has a cylindrical shape attached to a tip end of a drive device through a connecting portion having a bendable joint structure in a pile extraction excavating casing. It is characterized in that a screw-shaped ring is provided at the tip of the outer peripheral surface of the casing.

[0009]

The screw-shaped ring functions as the excavation traction force at the tip of the casing during excavation and maintains the excavation directionality. Then, the joint mechanism of the drive device and the casing follows the turning blur in the excavating direction centered on the excavating direction and the screw-shaped ring being excavated, which is connected to the base of the casing, and temporarily displaces in the driving direction and the excavating direction. However, the driving force is directly transmitted to the drive shaft as the excavating force of the spiral blade at the tip, and furthermore, the excavation of the sand around the pile by the screw ring facilitates the operation and lifting of the gripping mechanism of the pile. it can.

In order to give a straight-line traction force to the screw blade at the tip, it is sufficient to wind around the casing 1 to 3 times,
In the usual case, the one whose outer peripheral surface is wound once and a half turns has the best traction.

[0011]

FIG. 1 shows the appearance of a casing 1 of the present invention,
FIG. 2 is a view showing the cross-sectional structure taken along the line AA of FIG. 1, showing a state in which the existing pile K is held inside.

In these figures, water is introduced into the side surface of the casing 1 from a ground auger by a hose 21,
It is made of a steel pipe having a water introducing passage 2 through which water is jetted inward from the water discharge port 22 at the lower end. A plurality of digging blades 3 protruding outward from the outer surface of the casing are fixed to the peripheral surface of the tip of the casing 1 at equal intervals.

A pile pressing cam 4 is rotatably arranged on the lower peripheral side surface of the casing 1. The pile pressing cam 4 is formed in an L shape as shown in FIG. 2, and the casing 1 digs around the existing pile K and is pushed down so that the tip of the casing 1 encloses the existing pile K. When it comes to a position, it is formed by a wire driving device (not shown) to rotate vertically around a fulcrum 6 and the inside of the cam 4 presses the outer surface of the pile to hold the existing pile K. There is.

Further, a screw-shaped ring 7 is provided on the peripheral wall of the casing immediately above the digging blade 3 at the tip of the casing 1 by spirally welding an elongated steel plate, an L-shaped steel material or the like and winding it once and a half turns. .

A mounting plate 8 is provided on the upper end of the casing 1.
Is provided, and the joint plate 10 of the drive unit 15 connected to the earth auger and the joint structure 10 that moves freely.
Are linked by.

FIG. 3 is an exploded perspective view showing the structure of the joint structure 10.

In the figure, the mounting plate 8 of the casing and the connecting plate 9 of the drive unit 15 are each provided with a projection 12 provided with a hole 11, and the shaft body 13 has the connecting shafts in the cross direction. It is mounted in the hole 11 of the protrusion 12. As a result, as shown in FIGS. 1 and 2, the driving force of the driving device 15 for the earth auger is transmitted from the connecting plate 9 to the casing 1 via the mounting plate 8 in any direction.

FIG. 4 is a diagram showing the operation of the pile pulling device having such a structure.

In the figure, the casing 1 is attached to the lower end of the earth auger 16 of the pile driver 14 using the joint mechanism 10 shown in FIG. 3 (a).

Next, while rotating the earth auger 16,
Proceed around the existing pile K (b). At the stage of this excavation propulsion, the excavation direction of the casing 1 is read by the screw-shaped ring 7 provided at the tip portion of the casing 1, and the casing 1 is pushed vertically along the outer peripheral surface of the existing pile K, and The tip reaches the tip of the existing pile K (c). Further, the wire 5 shown in FIG. 2 is pulled up to press the cam 4 against the outer peripheral surface of the existing pile K to strongly hold the pile K (d). Then, the casing 1 is pulled up together with the existing piles K in which the earth auger 16 is rotated (e).
(F) shows the casing 1 and the existing piles K after being pulled up. Then, the work is completed by burying earth and sand in the formed hole (g).

[0021]

In the pile pulling-out device of the present invention, since the mounting portion of the drive unit and the casing has a bendable joint structure and the screw blade is provided only at the tip of the casing, the vertical state can be easily maintained. It becomes possible, and by bouncing up the excavated soil, it is possible to smoothly excavate and pull up the pile.

[Brief description of drawings]

FIG. 1 is a perspective view showing an appearance of a casing of the present invention.

FIG. 2 is a view showing the cross-sectional structure taken along the line AA of FIG. 1 in a state in which a driven pile is placed inside and held in the pile.

FIG. 3 is an exploded perspective view showing the structure of a joint structure between the upper end of the casing and the lower part of the drive device.

FIG. 4 is a diagram showing an aspect of a pile pulling-out method by the device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing 2 Water introduction path 3 Excavation blade 4 Pile pressing cam 5 Wire 6 Support point 7 Screw ring 8 Mounting plate 9 Connecting plate 10 Joint structure 11 Hole 12 Projection body 13 Shaft body 14 Pile driver 15 Drive device 16 Earth auger 21 Hose 22 Spout K Existing pile

Claims (1)

[Claims] 1. A pile pulling-out device in which a cylindrical casing provided with a water discharge port opening inward and a mechanism for holding and holding a pile when it is pulled up is pushed in and attached to the tip of a rotary drive device. In the pile extracting device, the cylindrical casing and the push-in rotation drive device are connected to each other through a bendable joint structure, and a screw ring is provided at the tip of the outer peripheral surface of the cylindrical casing.