JP2582719B2 - Piling method and casing pipe used in the method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a method for removing concrete piles, pine piles, and the like that are no longer necessary for removing old buildings and making them uncovered in redevelopment of an urban area. Related to casing pipes used for

[0002]

2. Description of the Related Art An upper end of a casing pipe having an inner diameter 100 to 200 mm larger than an outer diameter of a pile is connected to an auger via a joint, and the casing pipe is rotated along a periphery of the pile with a friction cutter provided at a lower end while rotating the casing pipe. When the pipe reached the lower end of the pile, the casing pipe was pulled out, and a wire rope was hung on the pile and pulled out. FIG. 3 shows a state in which digging is performed with a friction cutter at the lower end of the casing pipe. In the figure, 1 is a pile, 2 is a casing pipe, 3 is a friction cutter, and 5 is a discharge hole, which is bored at an appropriate interval in the longitudinal direction of the casing pipe 2. The casing pipe 2 is rotated around the axis as shown by the arrow 6 to dig around the pile 1, and the excavated soil passes between the inside of the casing pipe 2 and the pile 1 as earth removal, and is above the ground surface. It is discharged from one of the several discharging holes 5 that have come out. Water is supplied into the casing pipe 2 as necessary, and a part of the water is supplied to the inner and outer peripheral surfaces of the casing pipe 2 by discharging a part of the water to the outside from an earth discharging hole 5 in the middle of the pipe. In some cases, water or air may be ejected from the lower end of the casing pipe. This is to reduce the frictional resistance of the rotation of the casing pipe.

[0003]

The frictional resistance reducing means of such a conventional method mainly reduces the frictional resistance of the outer peripheral surface of the casing pipe, and reduces the frictional resistance of the inner peripheral surface of the casing pipe. Not very effective. According to such a method, when digging with a friction cutter, when the frictional resistance between the inner peripheral surface of the casing pipe and the pile side increases, the pile may be broken by a torsional force in the middle. In this case, when excavating around the pile and extracting the pile, there is a problem that the lower part from the broken position of the pile remains in the ground and can not be extracted, and the upper part from the broken position of the pile is There is a problem that it remains firmly fixed in the casing pipe and cannot be easily taken out of the casing pipe. An object of the present invention is to provide a pile removal method capable of preventing a pile from being broken by preventing a pile to be removed from being fixed in a casing pipe.

[0004]

According to the present invention, there is provided a pile removing method comprising:
When digging along the outer periphery of the pile with a casing pipe having a friction cutter at the lower end, extracting the casing pipe after digging to the lower end of the pile, and then digging with the casing pipe in the pile removal method of extracting the pile, to guide the lower end of the casing pipe along the pile by guide means friction cutter is always provided at the lower end of the casing pipe to drill the outer side of the outer peripheral surface of the pile, on the且one casing pipe
Supplying end Karake over single pipe to the pressurized fluid, delivery to the surface side through between the inner peripheral surface of the outer peripheral and drilled borehole of the casing pipe with Kezudo drilling from the lower end of the supplied pressurized fluid to the casing pipe It is characterized by digging while digging. In the method, compressed air is preferably used as the pressurized fluid. In the method, the pressurized fluid is preferably compressed air and water. Further, casing pipe to be used for the pile vent construction method, overtake it and auger coupling means to the upper end portion provided with a friction cutter at the lower end of sufficiently large internal diameter of the steel tube than the outer diameter of the pile which及beauty the steel pipe in the
A pressurized fluid supply unit is provided, and an annular convex portion whose inner diameter is larger than the outer diameter of the pile protrudes from the inside of the cutter or the inner peripheral surface of the steel pipe near the cutter slightly above the cutting edge position of the friction cutter. The configuration characterized by the following is optimal.

[0005]

According to the above-mentioned construction method, the friction cutter provided on the ordinary casing pipe excavates a range slightly larger than the thickness range of the casing pipe, and the inner peripheral surface of the excavation hole and the outer peripheral surface of the casing pipe are excavated. , An inner small gap is formed between the outer peripheral surface of the pile and the inner peripheral surface of the casing. Pressurized fluid is supplied through the inner small gap. Most of the excavated soil does not enter the inside of the casing pipe but exits to the outer small gap. That is, since the pressurized fluid exists in the inner hole of the casing pipe, the pressurized fluid moves to the outside of the casing pipe through the cutter portion at the tip of the casing pipe, and passes through the outer small gap, that is, the outer periphery of the casing pipe. The pressure fluid and the excavated soil move upward between the surface and the inner peripheral surface of the excavation hole, and at this time, the excavated soil moves. Therefore, the pressurized fluid and the excavated soil are sent to the ground surface along the outer periphery of the casing pipe. For this reason, the frictional resistance between the inner peripheral surface of the casing pipe and the pile side is almost eliminated, and the mixture of the supplied fluid and the discharged soil is interposed between the outer peripheral surface of the casing pipe and the inner peripheral surface of the drilling hole. The frictional resistance is small because of good fluidity. Therefore, the rotation resistance of the casing pipe is small, and the inner peripheral surface of the casing pipe is not fixed to the pile side . Casing pipes and piles in connection with these
Deviation from the axis, that is, eccentricity is expected.
Because the cutter does not touch the pile, the pile is shaved and folded.
There is nothing to make the cause.

[0006] The casing pipe used in the pile removal method has an annular projection, so that even if the casing pipe is eccentric when digging along the pile, the annular projection is formed before the cutter contacts the pile. Prevents cutting piles in contact. In addition, between the inner peripheral surface of the casing pipe and the outer peripheral surface of the pile, soil that cannot be reached by the friction cutter remains on the outer peripheral surface of the pile, but the soil remaining on the outer peripheral surface of the pile is equivalent to an annular convex portion. Since the portion is scraped off, the amount of excavated soil between the pile and the bore of the casing pipe is further reduced.

[0007]

An embodiment of the present invention will be described with reference to FIGS. The casing pipe 11 used in this embodiment is:
It is almost the same as the casing pipe 2 shown in FIG.
The difference is that there is no earth discharging hole 5 and that the annular convex portion 4 is provided. As shown in FIG. 2, the casing pipe 11 is used by being connected to an auger via a joint 12 connected to the upper end thereof. The auger has, for example, a configuration supported by a truck crane or a rough terrain crane. An air source capable of supplying compressed air of 10 kg / cm ² is separately prepared, and compressed air is supplied from the auger to the casing pipe 11 through the joint 12. Be ready to supply. In addition, water can be supplied through the joint 12 as needed.

In this embodiment, a pile to be removed is a concrete pile 13 having a diameter of 400 mm, and a casing pipe 11 having an inner diameter of 500 mm is used. In FIG. 2, the joint 12 and the casing pipe 11 are connected by three L-shaped notches 14 provided at the lower edge of the joint 12 and three horizontal notches 14 welded to the upper end of the casing pipe 11. This is a configuration in which the projection 15 is engaged. In the figure, reference numeral 16 denotes an airtight packing. Friction cutter 3
Is the same as that shown in FIG. This cutter 3 is welded to the lower end of the casing pipe 11. Annular protrusion 4
Is obtained by welding a round bar for a reinforcing bar having a diameter of 25 to 32 mm in an annular shape inside the cutter slightly above the cutting edge of the friction cutter 3.

[0009] Concrete pile 1 using such a device
3 can be pulled out of the casing pipe 11 from directly above the pile 13.
Is lowered and rotated to dig along the outer periphery of the pile 13. At this time, compressed air and water are supplied. The compressed air passes through the inner hole of the casing pipe 11, passes through the position of the friction cutter 3, exits the casing pipe 11, and moves upward through the gap 18 between the outer peripheral surface of the casing pipe 11 and the inner peripheral surface of the excavated hole 17. It moves and erupts to the surface. At this time, since the compressed air moves with the excavated soil, the excavated soil rises in the gap 18 and is discharged to the ground surface side. In addition, water cools the friction cutter 3 during excavation and mudifies excavated soil to give fluidity, thereby facilitating transfer by air by a water sealing action. In addition, it is not necessary to supply water in the case of soil containing considerable moisture. Friction cutter 3
Reaches the lower end of the pile 13, the casing pipe 1
1 is pulled up, a wire rope is wound around the upper end of the pile 13 and joined, and the pile 13 is pulled out by a crane through the wire rope.

When the casing pipe 11 is rotated and excavated, air pressure acts on the inside of the casing pipe 11 so that the excavated soil moves almost outward, so that the outer peripheral surface of the pile 13 and the inner peripheral surface of the casing pipe 11 There is no clogging of soil or sand between the piles,
The force for rotating 3 hardly acts. Therefore, the pile 13 is not broken by the torsional force.

In the above embodiment, the friction cutter 3 used was the same as the conventional one, but was provided with vertical cutouts and grooves so that the excavated soil could easily move upward and outward on the friction cutter portion by air pressure. May be used. Further, the direction of the blade of the cutter may be provided in consideration of the direction such that the excavated soil is pushed outward by rotation. Moreover, although the circular convex part 4 used the round bar,
The cross section does not necessarily have to be a circular cross section, and may be a quadrilateral or hexagonal cross section. The point is that even if the casing pipe is eccentric when digging, the annular projection 4 hits before the cutter 3 hits the pile 13 so that the cutter does not cut the pile. It may be provided. The annular projection 4 is essentially the tip of the casing pipe
Is guided along the pile substantially.
The ter does not cut the pile. In the above embodiment, the casing pipe 11 is formed separately from the joint 12 so as to be detachable. However, even if it is formed integrally, there is no particular problem.

[0012]

According to the method of the present invention, when digging with a casing pipe along the outer periphery of a pile to be removed, a casing pipe having no earth discharging hole is used, and a pressurized fluid is supplied into the casing pipe. The extruded material is pushed out along the outside, so that the excavated soil does not become clogged between the inner peripheral surface of the casing pipe and the outer peripheral surface of the pile, so that the casing pipe and the pile are stuck. Is prevented. Therefore, <br/> or al little torsional force is not acted on the pile, and the pile since there also be cut with a cutter,
It never fold is. Further, since the pile is not broken in the casing pipe, there is no need to take out the pile.
Therefore, there is an effect that the pile removing operation can be performed efficiently without failure. ADVANTAGE OF THE INVENTION According to the casing pipe of this invention, the damage by the friction cutter of a pile is prevented, excavated soil is hard to enter between a pile and a casing pipe, breakage by the torsional force of a pile, and the pressurized fluid This has the effect of securing the supply passage.

[Brief description of the drawings]

FIG. 1 is a schematic vertical sectional side view for explaining an excavation process according to an embodiment of the present invention.

FIG. 2 is a partially cutaway enlarged view of a casing pipe and a joint used in the embodiment, partially omitted.

FIG. 3 is a schematic longitudinal sectional side view showing a conventional excavation process using a casing pipe for removing piles.

[Description of Signs] 3 Friction cutter 4 Annular convex portion 11 Casing pipe 12 Joint 13 Concrete pile 17 Drilling hole 18 Gap

Claims (4)

(57) [Claims] 1. A pile removing method in which a casing pipe having a friction cutter at a lower end digs along an outer periphery of a pile, digs to a lower end of the pile, extracts a casing pipe, and then extracts the pile. when burrowing by pipes, to guide the lower end of the casing pipe along the pile by guide means friction cutter is always provided at the lower end of the casing pipe to drill the outer side of the outer peripheral surface of the pile,且one Keshi
The pressurized fluid supplied to the upper portion Karake over single pipe of Ngupaipu, the lower end of the casing pipe to supply the pressurized fluid
Pile vent method, wherein a burrowing while feeding on the ground side through between drilling of the inner peripheral surface of the excavation hole was excavated and the outer periphery of the casing pipe with Kezudo. 2. The pile removing method according to claim 1, wherein the pressurized fluid is compressed air. 3. The pile removing method according to claim 1, wherein the pressurized fluid is compressed air and water. Wherein the pressurized fluid supply unit for auger coupling means及beauty said steel tube provided at an upper end portion provided with a friction cutter at the lower end of sufficiently large internal diameter of the steel tube than the outer diameter of the pile to be overtake, the friction An annular projection having an inner diameter larger than the outer diameter of the pile is protrudingly provided on the inside of the cutter or on the inner peripheral surface of the steel pipe close to the cutter at a position slightly higher than the cutting edge of the cutter. To the casing pipe.