JPH0641959A - Withdrawing device for existing concrete pile - Google Patents

Abstract

PURPOSE:To improve withdrawing efficiency by fittedly inserting the tip of a screw blade attached to the tip of an auger shaft into the hollow hole of a concrete pile, and rotating and lowering it, and applying centrifugal pressing force to the peripheral wall of a pile from its inside to crush the peripheral wall. CONSTITUTION:A casing 7 having an auger shaft 5 set in its inside is set on the head part of an existing pile P, and lowered as the shaft 5 is rotated to fit the tip side 10a of a screw blade 10 in the hollow hole P1 of the pile P. Since the outside diameter of the blade 10 enlarges gradually with the lowering of the shaft 5, the blade 10 is pressed in the inside of the hole P1. Since the blade 10 is in rotation in this case, centrifugal pressing force acts on the peripheral wall P2 of the pile P from inside, and the above force acts concentratedly from the wall P2 toward an end face P4 to crush the lowest strength end face P4 first and then the peripheral wall P2 in order. In addition, a screw blade 5a discharges crushed scraps together with a reinforcement cut by a cutter 11. Thus withdrawing hour can be sharply shortened, and the occurrence of noise and dust can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an existing concrete pile removing device for crushing and removing concrete piles, concrete piles and the like (hereinafter simply referred to as concrete piles) remaining in the ground after dismantling an existing building.

[0002]

2. Description of the Related Art When dismantling an existing building and constructing a new building at that location, it is necessary to remove the concrete piles driven into the ground because they interfere with the construction. As a removal device of this kind, while pouring water around the concrete pile, insert a casing equipped with a digging blade into the ground, pull out the casing after this insertion, and then remove the wire rope from the top of the concrete pile. A device was used to remove the concrete pile by lifting it up. However, according to this removal device, when the concrete pile is lifted, the wire rope entangled in the upper part of the concrete pile extends upward from one place on the outer periphery of the concrete pile, so that the pulling force is increased. It will be off from the axis of the pile. Then, the outer peripheral surface of the pile is pressed against the soil around the concrete pile, and there is a difficulty in that the concrete pile cannot be smoothly pulled out and removed. Therefore, recently, a pile crushing device for crushing the end surface of the concrete pile and removing the concrete pile has been proposed (as one example, JP-A-63-16122).
No. 2).

In this crushing device, a screw having a crushing blade is provided at the lower end of an auger shaft connected to a rotation driving means, and a guide cap having a cutting blade is provided. As a result, when the auger shaft is driven and lowered, the outer peripheral soil of the concrete pile is excavated by the cutting blade and the end surface of the concrete pile is crushed by the crushing blade. At this time, the crushed concrete fragments are discharged by the screw, but the rebar exposed due to the crush is projected from the upper end opening of the guide cap and is entangled in the rod. Then, after crushing the concrete pile, the concrete pile can be removed by pulling out the rod and gas-melting the reinforcing bar.

[0004]

However, since the concrete pile crushing device uses a crushing blade that rotates together with the cutting blade, the end face of the concrete pile is scraped off, which requires a considerable amount of time for crushing. However, the efficiency was low. Further, since the rebar exposed by the crushing needs to be entangled in the rod and pulled out and then melted by gas, there is also a drawback that a complicated work is involved.

An object of the present invention is to solve the above problems.

[0006]

In the present invention, in order to achieve the above-mentioned object, the outer diameter of the auger shaft connected to the rotation driving means is gradually increased from the tip fitted into the hollow hole of the concrete pile. It is provided with a screw blade to be enlarged.

[0007]

With the above construction, when the auger shaft is rotated and lowered, the tip of the screw blade is fitted into the hollow hole of the concrete pile. When the auger shaft is further lowered, the outer diameter of the screw blade is gradually increased, so that the screw blade is pushed into the hollow hole. At this time, centrifugal force is applied from the inside to the peripheral wall of the concrete pile by the rotation of the screw blade. And since this pressing force acts in a concentrated manner from the peripheral wall of the concrete pile to the end face as the screw blade descends, the end face with the lowest strength is first crushed, and the peripheral wall is sequentially destroyed from the inside. , The concrete pile will be removed.

[0008]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall configuration diagram of an existing concrete pile removing device.

In this existing concrete pile removing device, a drive device 4 is provided on a leader mast 2 of a crawler crane 1, and the drive device 4 includes an auger shaft 5 for mounting a screw blade 10 and a casing rotating device for mounting a casing 7. The mechanisms 6 are connected to each other and configured to crush the existing concrete piles P buried in the ground.

The drive unit 4 contains a motor and a speed reducer in a main body case 4a. And body case 4
A wire 3 is stretched between the upper portion of a and the headstock 2a of the leader mast 2, and a guide portion 4b is provided on a side portion of the main body case 4a. Thereby, the drive device 4 is
By winding and unwinding the wire 3, the leader mast 2
It is movable up and down along the guide rail 2b. Two
Reference numeral c is an antivibration tool for the casing 7.

The auger shaft 5 is connected at its upper end to a speed reducer, and is provided on its outer periphery with screw blades 5a for discharging crushed concrete fragments, rebar chips, and the like. A rod 8 is detachably attached to the lower end of the auger shaft 5. A pair of guide members 9, 9 for guiding the descent of the auger shaft 5 are fixed to the lower end of the rod 8 by welding.

The screw blade 10 is shown in FIGS.
As shown in Fig. 10, the tip side 10a is gradually reduced in the centripetal direction
Of the inner peripheral surface P2 (shown by an imaginary line in FIG. 3) of the hollow hole P1 of the concrete pile P to be removed is the minimum outer diameter portion 10b (the portion having the smallest radius from the axis of the auger shaft 5) The inner diameter of the hollow hole P1 is smaller than the inner diameter W1 of the hollow hole P1.
It is easy to fit in 1. Further, the maximum outer diameter portion 10d (the portion having the maximum radius from the axial center of the auger shaft 5) on the upper side 10c where the outer diameter gradually increases in the centrifugal direction is a concrete
It is inside the outer circumference of the toe P and has a smaller diameter than its outer diameter W2. As a result, when the auger shaft 5 descends with rotation, the auger shaft 5 is gradually pushed into the hollow hole P1 from the tip end side 10a to apply a pressing force in the centrifugal direction to the peripheral wall P3 of the concrete pile P, thereby breaking the peripheral wall P3. It has a so-called seri arrow structure, and the crushed concrete piece can be further crushed by the maximum outer diameter portion 10d.

On the opposite side of the screw blade 10, as shown in FIG.
Further, as shown in FIG. 4, a cutter 11 for cutting the reinforcing bar is provided. In this cutter 11, the lower end on the tip side 11a is substantially parallel to the end face P4 of the concrete pile P,
It facilitates cutting of the reinforcing bar exposed when the concrete pile P is crushed. The cutter 11 and the screw blade 10 are provided from the rod 8 to the auger shaft 5, but the cutter 11 and the tip side portions 10a, 11a of the screw blade 10 are exchangeable. That is, the tip end side portions 10a and 11a are firmly fixed to the rod 8 by welding. When the upper portion of the rod 8 is connected to the lower portion of the auger shaft 5, they are connected to the screw blades 5a and 5b, respectively. It is like this.

The casing rotating mechanism 6 includes a body portion 6a.
The main body 6a including a motor is fixed to the drive device 4 and the lower rotary portion 6b is rotated.

The casing 7 has a diameter slightly larger than the outer diameter W2 of the concrete pile P, and the upper side thereof is connected to the rotating portion 6b, which is interlocked with the rotation of the rotating portion 6b. Then, at the lower end of the casing 7, as shown in FIG.
As shown in FIG. 5, an excavating blade 7a is provided so that the outer peripheral soil of the concrete pile P is excavated when the casing 7 rotates.

Next, the concrete pile crushing process by the existing concrete pile removing device will be described. First, the casing 7 in which the auger shaft 5 is set,
As shown in FIG. 5, the concrete pile P remaining in the ground is built on the head, and the casing 7 is inserted into the outer periphery of the concrete pile P.

Next, when the auger shaft 5 is rotated and lowered, the tip side 10a of the screw blade 10 is, as shown in FIG.
Is inserted into the hollow hole P1 of the concrete pile P.

Further, when the auger shaft 5 descends, the outer diameter of the screw blade 10 gradually increases, so that the hollow hole P1
The screw blade 10 is pushed into the inside. At this time, since the screw blade 10 is rotating, a pressing force in the centrifugal direction is applied to the peripheral wall P2 of the concrete pile P from the inside. The pressing force acts in a concentrated manner from the peripheral wall P2 of the concrete pile P toward the end face P4 as the screw blade 10 descends, and is thus crushed from the end face P4 having the lowest strength, as shown in FIG. Thus, the peripheral wall P2 is sequentially destroyed. Where the concrete debris is
Further crushed at the maximum outer diameter portion 10d. Further, since the lower end of the cutter 11 is substantially parallel to the end face P4 of the concrete pile P, the reinforcing bar (not shown) exposed when the concrete pile P is crushed is cut as shown in FIG. It Thus, the crushing of the end face P4 by the screw blade 10 and the cutting of the reinforcing bar by the cutter 11 are performed simultaneously, so that the peripheral wall P2 is efficiently destroyed. Then, the crushed concrete fragments, the chips of the reinforcing bars, etc. are discharged by the screw blades 5a, so that the concrete pile P is removed to the lower end portion. The casing 7
Since it descends while excavating the soil around the concrete pile P, noise generated due to crushing of the concrete pile P in a portion near the ground can be suppressed and dust scattering can be prevented.

[0020]

As described above, according to the present invention, when the auger shaft is rotated and lowered, the tip of the screw blade whose outer diameter is gradually enlarged is fitted into the hollow hole of the concrete pile, and Since the pressing force in the centrifugal direction is applied to the peripheral wall from the inside, the peripheral wall can be crushed sequentially from the end face having the lowest strength. Therefore, as compared with the conventional case where the end surface of the concrete pile is removed while being cut with a crushing blade or the like, the removal time of the concrete pile is significantly shortened, and the work efficiency is significantly improved.

Further, if a cutter for cutting the reinforcing bar is provided in the vicinity of the screw blade, the reinforcing bar in the concrete pile is also cut at the same time when the concrete pile is crushed, and the concrete pile is efficiently crushed, further improving the work efficiency. Can be made.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention.

FIG. 2 is a front view of a screw blade.

FIG. 3 is a front view of the cutter.

FIG. 4 is a back view of a screw blade and a cutter.

FIG. 5 is an explanatory diagram showing a preparatory stage when removing an existing concrete pile.

FIG. 6 is an explanatory view showing a state where the existing concrete piles have begun to be crushed.

FIG. 7 is an explanatory diagram showing a state where an existing concrete pile is being crushed.

FIG. 8 is an explanatory view showing the middle of crushing an existing concrete pile.

[Explanation of symbols]

 1 Crawler Crane 2 Leader Mast 4 Rotational Drive Means 5 Auger Shaft 10 Screw Blade 10a Tip 11 Cutter for Cutting Rebar P Concrete Pile P1 Hollow Hole

Claims (2)

[Claims] 1. An apparatus for removing an existing concrete pile, comprising a screw blade whose outer diameter is gradually increased from a tip end inserted into a hollow hole of the concrete pile at a lower end portion of an auger shaft connected to a rotation driving means. 2. The existing concrete pile removing device according to claim 1, further comprising a cutter provided near the screw blade for cutting the reinforcing bar.