JPS63147013A - Drawing-out of pile and excavating casing therefor - Google Patents

Abstract

PURPOSE:To permit effective operations by a method in which a pile is drawn out while being hugged by a casing. CONSTITUTION:The surrounding ground of an existing pile 5 is excavated by covering the pile 5 while turning a casing 100 having excavating mechanism and a pile-holding mechanism 10. In pulling up the casing 100, the pile 5 is pulled out while being hugged. The pile 5 can thus be effectively and safely drawn-out.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for pulling out foundation piles driven during the construction of a previous building when a building is being rebuilt, and a device used therefor.

[Conventional technology]

When constructing a new building in the same location as the old building,
The foundation piles of the old building need to be removed.

Such removal of foundation piles has conventionally been carried out in accordance with the procedure shown in FIG. 11.

Referring to the same figure, as shown in +a), attach the casing l to the lower end of the earth auger 3 of the pile driver 2, and as shown in (bl and (C)), attach the casing 1 to the tip while rotating. Excavate around the resistor 5 using the tool 4. (d
), after the excavation to the depth of the tip of the shaft 5 is completed, the casing 1 is pulled up as shown in tel. After that, wire 6 is attached to the tip of resistor 5 shown in ffl, and (
As shown in gl, the drag 5 is pulled out by a crane, and finally, as shown in (1), sand 9 is thrown into the excavated hole 7 after the remaining drag is pulled out, as shown in (1). to finish the work.

[Problems to be Solved by the Invention] However, in the above conventional method, the excavation of the casing and the lifting of the piles are performed separately after the casing is pulled up, so efficiency is low, and furthermore, the piles that have been driven are In the case of a multi-stage shaft, there is a disadvantage that the lower pile remains and it takes a lot of effort to pull it out.

The problem to be solved by the present invention is to eliminate the drawbacks of the conventional pulling method described above, and to make it possible to pull out piles more efficiently, and to make it possible to pull out piles even when the piles are multi-stage. The object of the present invention is to provide a method for extracting the same, and an apparatus for carrying out the method.

[Means for solving problems]

The present invention provides an excavation mechanism and a pile entrapment mechanism in the casing itself, excavates around the pile by using the casing to cover the driven pile, and when the casing is pulled up, the pile entrapment mechanism is activated to remove the driven pile. This solves the above problems all at once by lifting the device while it is tucked in.

Referring to FIG. 1 showing an aspect of the pile extraction method of the present invention, a pile enclosing mechanism 10 is provided on the lower side surface of a casing 1, and the casing 1 is rotary excavated in the same manner as the conventional method shown in FIG. (As shown in d+, in the process of pulling up the casing l after reaching the tip of driving the pile 5, the pile holding mechanism 10 is activated to grasp the resistor 5 and simultaneously lift the casing l. This is done by Since the Tgl step is omitted from the conventional method (e) shown in FIG. 11, the overall efficiency of the work can be improved accordingly.

Furthermore, by providing the pile accommodating mechanism 10 at a lower position of the casing 1, the pile can have an upper resistance 5 as shown in the figure.
1 and the lower pile 52, the upper pile 5
It is also possible to lift a multi-stage shaft in one step without having to lift only one shaft.

Furthermore, the present invention is characterized by the structure of a casing for carrying out the above method, and the casing has a water introduction passage that opens inward at the bottom of the casing, and a water introduction passage that is contained in the casing when the casing is pulled up. It is equipped with a pile-engaging mechanism that locks onto the surface of the pile.

FIG. 2 shows a first embodiment of a casing structure for carrying out the method of the invention.

Fig. 3 is a sectional view taken along the mm line in Fig. 2, and Fig. 4 is a sectional view taken from the line IV-IV in Fig. Figure 5 is an external view of the cam used in the pile-engaging mechanism.

In the same figure, it is preferable to provide two or more pile entrapment mechanisms lO around the casing 100 in order to safely enclose the driven piles. However, the installation level must be the same for each pair. However, from the viewpoint of gripping efficiency for a relatively long pile, it is better to install two on the lower facing surface, and two on the upper and lower sides so that the positions intersect with each other to support the pile at two points above and below. This is convenient in terms of support efficiency.Moreover, the upper holding mechanism can be installed at a distance from the bottom end of the casing that is shorter than the length of each pile of the multi-stage shaft. In the case of piles, the lower pile will not be left behind.

As shown in FIG. 5, the pile-engaging mechanism 10 has a rounded abutting part 11 for the pile and a sharply curved tip part 12 at the other end to absorb the resistance of earth and sand. cam 13 with
is rotatably attached.

The cam 13 has a casing 100 as shown in FIG.
The cutting blade 14 at the tip of the casing 100 is attached in a direction opposite to the cutting edge of the cutting blade 14 so that it does not expand when rotated for excavation, but expands due to resistance when rotated in the opposite direction and grips the driven pile. ing.

15 introduces water into the inside of the casing 100 from the auger attachment part 16 during excavation, and as shown in FIG. The water introduction channel for spouting is shown.

FIG. 6 shows the operation of the pile-engaging mechanism 10 when the casing 100 embraces and pulls up the driving shaft 5 after rotary excavation of the casing 100 as shown in FIG. FIG. 3 is an enlarged view showing a rotating state of a cam.

Referring to these figures, while excavating while rotating the casing 100 in the direction shown by the solid line arrow ((bl, t in Fig. 1)
Water is supplied into the casing 100 from the water outlet 17 shown in FIG. At that time, the cam 13 is in the position shown by the solid line.

Next, as shown in FIG. 1 1dl, after the casing 1 reaches the lowest position, the casing 1 is reversely rotated in the direction shown by the dashed line in FIG. At this time, the casing 100
The outer tip 12 of the cam 13 receives a resistance of ±19 at the outer position of
The cam 13 can be rotated in the direction of the dashed line shown in FIG. This rotation causes the abutting portion 11 of the cam 13 to press and lock the surface of the resistor 5.

Therefore, by pulling up the casing 100 while rotating it in the opposite direction to the excavation direction, the existing driven pile can be pulled out while being held inside the casing.

In the first embodiment, the cam 13 of the pile holding mechanism 10
Although the pile is held in with the casing 100 rotated in the opposite direction to the excavation direction, it is possible to adopt a mechanism that carries out the cam holding without such reverse rotation.

FIG. 8 shows a second embodiment of the casing mechanism of the present invention.

In the same figure, the casing 200 has a holding cam mechanism 201 at two opposing locations in the lower position of the casing.
is provided. As shown in FIG. 9, this cam mechanism 201 has an L-shaped cam 202 attached by a pull wire 203 so as to rotate vertically about a fulcrum 204. The wire 203 for the cam 202 of the same type is wound up or unwound by operating a cam rotation mechanism 205 provided above the casing 200 shown in FIG. FIG. 1O shows details of the cam rotation mechanism 205 for this purpose.
06 indicates a piece for winding the wire 203, and when the wire 203 is pulled upward by rotating the ratchet handle 207, the cam 202 rotates in the direction of the arrow as shown in FIG. Lock the stake 5 so as to hug it.

Therefore, in the case of this second aspect, when pulling up the pile held in the casing, the casing is rotated in the opposite direction, making it possible to pull it up reliably.

〔Effect of the invention〕

With the present invention, driven piles can be pulled out efficiently and safely regardless of their form, and the piles used in old buildings, which have traditionally been a bottleneck in land redevelopment, can now be easily removed. , can contribute to improving the overall efficiency of redevelopment.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an aspect of the pile pulling method of the present invention, Fig. 2 is an external view of a first embodiment of the casing structure for carrying out the method of the present invention, and Fig. 3 is a diagram showing the aspect of the pile pulling method of the present invention. Fig. 4 is a sectional view taken from the line rV-rV in Fig. 2, showing the operating state of the pile entrapment mechanism, and Fig. 5 is a sectional view taken from the line rV-rV in Fig. 2. Diagram showing the outline of the cam used for
FIG. 6 is a diagram showing the operation of the pile holding mechanism, FIG. 7 is an enlarged view showing the rotating state of the cam, and FIGS. 8 to 10 are diagrams showing the second embodiment of the casing. FIG. 11 is a diagram showing an aspect of a conventional pile pulling method. 1: Casing 2: Pile driver 3: Earth auger 4: Tool 5' pile 6: Wire 7am drilling 8: Mini sill pel 9: That is, 10: Pile holding mechanism 11: Contact part
12: Pointed end 13: Cam 14: Cutting blade 15: Water introduction path 16: Auger attachment part 17:
Water outlet 18.19: Soil 51: Upward counter
52: Downward resistance 100: Casing

Claims (1)

[Claims] 1. Excavating around the pile while covering the existing pile while rotating a casing having an excavation mechanism and a pile enclosing mechanism, and driving by activating the pile enclosing mechanism when pulling up the casing. A method for pulling out a pile, comprising pulling up the casing while enclosing the pile. 2. The method for extracting a pile according to claim 1, characterized in that water is introduced between the casing and the pile during excavation. 3. An excavation casing used for pulling out piles, characterized by being provided with a water outlet opening inward, and a pile holding mechanism having a cam that is activated during pulling up and holds the outer surface of the pile. 4. The excavation casing according to claim 3, wherein a water discharge port opening inward is provided in a water introduction path communicating with an introduction port provided at the top of the casing. . 5. The excavation casing according to claim 3, characterized in that a plurality of cams are provided around the casing at intervals vertically, and the cams are arranged to engage the outer surface of the pile when the casing is pulled up. 6. The excavation casing according to claim 3, characterized in that the cam of the pile entrapment mechanism is configured to deploy only while the casing rotates in the opposite direction to the excavation rotation direction to carry out the pile entrapment operation. 7. The excavation casing according to claim 3, characterized in that the cam of the pile entrapment mechanism is operated by an operation from outside the casing.