JP2002188145A - Drawing casing for underground concrete pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily draw an underground concrete pile without crushing it. SOLUTION: A ribbon screw blade having an inner diameter slightly larger than the outer diameter of the underground concrete pile to be drawn is provided on the inner periphery of a steel pipe casing, and many lock pawls are protruded inward from the inner side of the blade at fixed intervals to form this extracting casing for the underground concrete pile.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for removing H remaining in the ground.
The present invention relates to a drawing casing for removing a concrete pile such as a concrete pile containing a core material such as a shaped steel, a PC or RC concrete pile, and a cast-in-place concrete pile.

[0002]

2. Description of the Related Art Conventionally, as a means for removing a concrete pile remaining in the ground, a steel pipe casing is vibrated by a vibratory hammer and pressed into the surroundings of the concrete pile in the ground. A method is known in which the earth and sand in the steel pipe casing is consolidated into a compacted state, and then the steel pipe casing is pulled out by a crane or the like, and simultaneously the underground concrete pile held by the compacted earth and sand is pulled out.

However, the above-mentioned conventional method has a drawback in that considerable noise and vibration are generated by driving the vibro-hammer, which adversely affects residents and buildings around the site, and requires a great force to pull out the steel pipe casing. In addition, there was a problem that the underground concrete pile was easily dropped out of the casing when being pulled out.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to pull out an underground concrete pile relatively easily without noise and vibration.

[0005]

As a means for solving the above problems, the present invention provides a ribbon screw blade having an inner diameter slightly larger than the outer diameter of an underground concrete pile to be drawn on the inner peripheral surface of a steel pipe casing. The present invention proposes an underground concrete pile pull-out casing in which a plurality of locking claws projecting inward from the inner side of the blade are provided at the ribbon screw blade at a certain interval. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A drawing casing (1) shown in FIG. 1 has a ribbon screw blade (3) having an inner diameter slightly larger than the outer diameter of an underground concrete pile to be drawn on the inner peripheral surface of a steel pipe casing (2). Projecting over the entire length of the casing,
On the inner side of the screw blade (3), a locking claw (4) ...
Are fixed to each other in a state of projecting inward from the screw blade (3) at a ratio of two per spiral. (5) ... is a discharging hole opened in the casing (2),
(6) is a digging blade formed at the lower end of the casing (2).

The locking claws (4) are formed by forming a trapezoidal three-dimensional chip (8) at the tip of a rectangular substrate (7) as shown in FIG. 2 as an example. 7)
In addition, two slots (9), (9), (9), (9) are provided in the row (9), (9), (9), (9) at right angles to the chip (8), and the slot (9) is formed on one surface of the substrate (7). ) Are formed in the direction perpendicular to the longitudinal direction of the ribbon screw blade (3), while the score lines (12) are formed on the upper surface of the ribbon screw blade (3) where the locking claws are to be attached. Base plate with (11)
Are welded so that the score lines (12) are oriented at right angles to the diametric direction of the casing (2), and the elongated holes (9) are formed in the screw blade (3) and the base plate (11).
Are provided at positions corresponding to.

The above-mentioned engaging claw (4) is provided with a notch line (10).
… Stack on the surface with bolts (14) ... through holes (13)
And the slot (9), and adjust the protrusion of the tip (8) of the locking claw (4) in the length range of the slot (9) to adjust the nut (15) at a desired protrusion. Tighten.

The operation of the above example will be described below together with a usage example. In this example, as shown in FIG. 1B, a hydraulic jack (17) for press-fitting a casing is erected on a base frame (16) having a rectangular frame shape, and the jack (17) is mounted on a lifting frame (18). ) Is supported so as to be able to move up and down by driving the jack, a rotatable cylinder (19) is rotatably supported by the elevating frame (18), and a chuck (20) for gripping a casing is provided on the rotatable cylinder (19). In addition, the casing rotating hydraulic motor (2) on the lifting frame (18)
1) A casing rotary press-fitting device that transmits rotation from (21) to the rotary cylinder (19) is used.

First, the rotary press-fitting device is installed on the ground centered on the underground concrete pile (P), and the drawing casing (1) is placed at the center of the rotary press-fitting device as shown in FIG. It is vertically held and is intermittently pressed into the ground by a fixed length while being rotated by the drive of the rotary press-fitting device. Thereby the drawing casing (1)
Is scraped by the ribbon screw blades (3) and conveyed upward in the casing (1) while descending around the underground concrete pile (P).
In the meantime, the tips (8) of the locking claws (4) bite into the brittle surface of the underground concrete pile (P).

When the drawing casing (1) is press-fitted to the lower end of the underground concrete pile (P), the underground concrete pile (P) is in the casing (1), and the surrounding soil and sand are removed or the underground concrete pile (P) is removed. Only the part of the soil that has been unpacked remains, thereby leaving the underground concrete pile (P) in a state where the connection with the ground is sufficiently released and easy to pull out.

Therefore, if the drawing casing (1) is intermittently raised by a predetermined length, the underground concrete pile (P) gripped by the locking claws (4) in the casing (1) is drawn together. be able to. In this case, the casing (1) may be rotated to facilitate pulling out of the casing (1).

In some cases, the casing (1) and the concrete pile (P) may be lifted by a wire using a crane.

In another embodiment shown in FIG. 3, the steel pipe casing (2a) is divided into two parts, one end of both halves is openably and closably connected by hinges (22a)... Are detachably connected by bolts (23a)... And nuts (24a). The other structures are substantially the same as those in FIGS. According to the present example, when the casing (2a) is opened, the work for adjusting the protrusion of the locking claw, the work for cleaning the inside of the casing (2a) after use, and the like become easy.

[0015]

According to the underground concrete pile pull-out casing of the present invention, when the underground concrete pile is pressed into the underground concrete pile while being rotated, the sediment around the underground concrete pile is rotated by the ribbon screw blades. Drains upwards, or leaves only part of the soil unsealed around, thereby leaving the underground concrete pile in a state where it can be easily pulled out with its connection with the ground sufficiently interrupted, Thereafter, the underground concrete pile gripped by the locking claws can be easily pulled out together with the casing.

[Brief description of the drawings]

FIG. 1A is a partially cutaway front view of a drawing casing according to the present invention. (B) A partially cut-away schematic diagram of a use state.

FIG. 2A is an enlarged vertical sectional view of a locking claw portion. (B) An enlarged perspective view of a locking claw.

FIG. 3 is an enlarged transverse cross-sectional view of a part of another embodiment.

[Explanation of symbols]

 1, 1a Pull-out casing 2, 2a Steel pipe casing 3, 3a Ribbon screw blade 4 Locking claw P Concrete pile

Claims (1)

[Claims] 1. A ribbon screw blade having an inner diameter slightly larger than the outer diameter of an underground concrete pile to be pulled out is provided on the inner peripheral surface of a steel pipe casing, and the ribbon screw blade is provided with an inside from an inner side of the blade. A drawing casing for underground concrete piles, in which a large number of locking claws protruding in the direction are protruded at regular intervals.