JP2004239041A - Pull-out device for pile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method being smoothly driven by decreasing frictional resistance between a pile and the ground by a device for pulling out the unnecessary pile in the ground. <P>SOLUTION: A copper pipe 12 with a short length is welded to the front end of a sheet pile 11, the copper pipe 12 having an inside diameter slightly larger than an outside diameter of the pile to be pulled out, and it is piled on the sheet pile 11 to weld. The copper pipe 12 is so mounted that the frictional resistance between the pile 1 and the ground is decreased. A water supply pipe 13 is mounted to the inside of the sheet pile 11. Since a closing part F surrounded by the sheet pile 11 and the pile 1 can be loosened by jetting high pressure water from a jet nozzle on the front end of the water supply pipe 13, as a result, a pull-out device 10 can be smoothly driven. Since the copper pipe can be driven in the ground by the time not longer than a half in comparison with a method 20 using the conventional copper pipe by using the sheet pipe 11, the method is very efficient and economical. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention eliminates the need for a support pile for a structure installed in the ground, so it is an apparatus for pulling out from the ground, reducing the surface area of the material to be driven into the ground as compared to the conventional method, Further, the present invention relates to a pile pulling device for reducing the driving time of the pulling device and improving the efficiency of the pulling operation by alleviating the closed state of the soil between the material to be driven and the pile.
[0002]
[Prior art]
As a device for pulling out unnecessary piles from the ground, use a steel pipe with an inner diameter larger than the outer diameter of the pile to be pulled out, in order to cut the frictional resistance between the pile and the ground under the ground, Attach a jet nozzle to the water guide pipe and the tip of the pipe, insert a pulling pile into the steel pipe, drive the steel pipe using a vibro hammer, and furthermore, while discharging high pressure water from the jet nozzle, The friction resistance with the ground has been cut.
In addition to a method of disposing a water pipe inside a steel pipe, a method of disposing a water pipe outside a steel pipe is generally and generally performed.
[0003]
[Problems to be solved by the invention]
The conventional method of using a steel pipe to cut the frictional resistance between the underground pile and the ground requires a long steel pipe to the tip of the pile to be withdrawn.
The frictional resistance of the soil when the steel pipe is driven into the ground is proportional to the sum of the surface area of the outer peripheral portion and the surface area of the inner diameter of the steel pipe.
If the pile to be withdrawn is long and has a large diameter, the pulling device is installed up to the tip of the pile because the frictional resistance of the soil is too large due to the large surface area of the steel pipe, even if high pressure water is ejected from the jet nozzle while driving. It is taking so much time.
[0004]
[Means for Solving the Problems]
Reducing the surface area of the device itself to be driven into the ground is the largest necessary condition for reducing the frictional resistance with the ground under the ground.
Therefore, claim 1 of the present invention is to shorten the steel pipe to be driven in order to cut the frictional resistance around the pile to be drawn, having a short tip only, weld it to the tip of the sheet pile, and apply high-pressure water inside the sheet pile. One or a plurality of feed pipes to be sent are attached, and high-pressure water is discharged from the jet nozzle at the tip of the feed pipe, and a sheet pile is driven by a vibro hammer while drilling around the pile.
Claim 2 uses two sheet piles and welds them so that a short length of steel pipe is pinched at the tip, and attaches the steel pipes at appropriate positions to reduce the buckling strength of joining the sheet piles to each other with a plate. It is an enhanced drawing device.
The pulling device according to claim 2 is highly effective when the pile to be pulled is long or when it is used on hard ground.
[0005]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a side view showing a pile pulling device according to the present invention. FIG. 2 is a cross-sectional view of a sheet pile portion AA, and FIG. 3 is a cross-sectional view of a front end portion BB of the present device. A short steel pipe is welded to the sheet pile.
FIG. 4 shows the same shape as that of FIG. 3 except that the position of the water guide pipe attached to the inside of the sheet pile is attached to the center of the flange surface of the sheet pile. It is a figure showing that it may be attached anywhere.
FIG. 5 is a side view showing the actual driving state of the drawing device of the present invention.
A specific construction and casting method will be described with reference to FIG.
A general method for driving both a vibro hammer and a jet is shown in FIG.
If the sheet pile 34 in FIG. 15 is replaced with the drawing device of the present invention, the construction procedure is the same.
First, a backhoe excavates from the ground surface to about 1.0 m below the top of the pile. Next, the pile pulling device 10 is lifted by the crawler crane 31 and inserted into the pile 1 from which the steel pipe 12 at the tip is pulled out. After the insertion is completed, the web at the top end of the sheet pile 11 is chucked to the chuck 34 attached to the tip of the vibro-hammer.
After the chucking is completed, the vibro of the vibro-hammer is driven, and driving is performed while jetting high-pressure water from the jet nozzle. As the driving proceeds, the frictional resistance of the soil to the driving increases. Specifically, as shown by the hatched portion in FIG. 6 showing the positional relationship between the pile and the sheet pile and the cross section taken along the line CC, the closed portion F between the pile and the sheet pile is compacted, and the soil of this portion is soiled. As the frictional resistance becomes very strong and the driving becomes deeper, the driving speed drops sharply due to the frictional resistance of the soil.
By discharging high-pressure water from the jet nozzle to the closed portion as described in claim 1 of the present invention, the ground of the closed portion can be loosened. As a result, the compacted state of the closed portion does not occur. In addition, the sheet pile of the drawing device can be driven smoothly.
FIG. 7 is a cross-sectional view taken along the line D-D showing the tip of the sheet pile. The steel pipe at the tip is welded to the sheet pile, and is provided for the purpose of separating the friction surface between the pile and the ground to eliminate frictional resistance of the soil. Furthermore, since the steel pipe is inserted into the pile, it also plays a role in driving the sheet pile vertically along the pile.
[0006]
FIG. 8 is a side view of the drawing device of claim 2. When the ground on which the pile is driven is hard or when the pile length is long, the buckling strength of one sheet pile is weak and the driving load is increased when the sheet pile length is long. Is insufficiently transmitted vertically.
In order to solve this point, in claim 2, two sheet piles are used, and in order to further increase the buckling strength, the sheet piles are joined to each other at a suitable position with a plate to reduce the buckling strength. In the form of an increased drawing device. By adopting this method, the buckling strength of the sheet pile is greatly increased, and the driving load is completely transmitted even to a long pile, so that the effect of pulling out the long pile is exhibited.
FIG. 9 is a cross-sectional view taken along the line EE of the sheet pile portion, and FIG. 10 is a cross-sectional view of the front end portion FF of the sheet pile.
[0007]
FIG. 11 is a front view showing a conventional general construction method used as a pile pulling device, FIG. 12 is a cross-sectional view of a steel pipe portion GG, and FIG. FIG. 4 is a cross-sectional view of the HH portion in a state where the water guide pipe is disposed inside the steel pipe. FIG. 14 shows a state in which the water guide pipe is attached to the outside of the steel pipe, and this shape is also commonly used.
[0008]
The difference between the present invention shown in FIG. 1 and the conventional general construction method shown in FIG. 11 with respect to the frictional resistance of the soil will be described with specific examples. There is a correlation between the frictional resistance of the soil and the surface area of the drawing device. That is, the smaller the surface area of the device, the easier it is to drive.
As an example,
Diameter of the pile to be drawn; D = 50 cm; pile length of the pile to be drawn; L = 20 m; conventional total surface area using a conventional steel pipe; A ₁
Considering the arrangement of the water pipe on the inner diameter,
Assuming that the outer diameter of the steel pipe is D ₁ ≒ 61 cm and the thickness is 1.2 cm,
A ₁ = {D ₁ + (D _1-2 × 1.2)} × π × L = 75.1 m ²
Total surface area of the drawing device of the present invention; A ₂
Outer diameter D _{2 of} steel plate = 53.5 cm, thickness 1.2 cm, length of steel plate 1 = 70 cm,
Assuming that the sheet pile FSP5L used (surface area: 1.75 m ² / m), A ₂ = {D ₂ + (D ₂ -2 × 1.2)} × π × 1 + 1.75 × L = 37.3 m ²
_{A 2 / A 1 = 37.3 /} 75.1 = 0.50 , and the
The device of the present invention shown in FIG. 1 has a surface area half that of the conventional general construction method shown in FIG. 11, and furthermore, the closed portion F between the pile and the sheet pile can be loosened with high-pressure water. It can be driven with less than half the frictional resistance of the conventional method.
[0009]
【The invention's effect】
As described above, according to the present invention, since the surface area is １ ／ as compared with the conventional drawing device, and the closed portion between the pile and the sheet pile can be loosened with the high-pressure water of the jet nozzle, the driving operation is reduced. Can be done in a very short time. Further, since the driving resistance is small and a large vibro hammer is not required, the crawler crane can be operated with a small object, so that it can be constructed at a low cost.
[Brief description of the drawings]
1 is a side view of a pile pulling device of the present invention; FIG. 2 is a cross-sectional view of a sheet pile portion AA; FIG. 3 is a cross-sectional view of a tip BB of the present device; FIG. 5 is a side view of a driving state according to the present invention. FIG. 6 is a cross-sectional view of a positional relationship CC between a pile and a sheet pile in a driving state. FIG. 7 is a sheet in a driving state. FIG. 8 is a side view of a drawing device for two sheet piles. FIG. 9 is a sectional view of a drawing device for two sheet piles EE. FIG. 10 is a drawing of two sheet piles. FIG. 11 is a side view of a conventional drawing device in a driven state. FIG. 12 is a side view of a conventional drawing device GG. FIG. 13 is a side view of a conventional drawing device. FIG. 14 is a side view of a portion HH into which a pile is inserted. FIG. 14 is a cross-sectional view of a water guide pipe outside type of a conventional drawing device. [15] General vibro-hammer over method status view implantation jet combination EXPLANATION OF REFERENCE NUMERALS
1. Pull-out pile 21. Long steel pipe10. Pile pull-out device 30. 10. Vibro hammer and jet combined use Sheet pile 31. Crawler crane 35. Sheet pile 32. Boom 12. Short steel pipe 33. Vibro hammer 13. Water pipe 34. Chuck 22. Water guide pipe 37. Jet nozzle 36. Water guide pipe 38. Aquarium 15. 39. Pulling device for two sheet piles Unit 16. Plate joint material F Blockage caught between pile and sheet pile 20. Conventional pile pulling unit

Claims (2)

In a device for extracting an underground pile, a steel pipe having a short length is welded to the end of one sheet pile, and the steel pipe has an inner diameter slightly larger than the outer diameter of the pile to be extracted, and is overlapped with the sheet pile. One or more water guide pipes are attached inside the sheet pile, and high pressure water is ejected from the jet nozzle at the tip of the water guide pipe while driving to reduce the frictional resistance between the pile and the ground. A pile pulling device, characterized in that: The inner diameter is slightly larger than the outer diameter of the pile to be pulled out, and a short steel pipe is welded so that it is sandwiched between the ends of two sheet piles. If the sheet pile to be used is long, place the sheet piles at appropriate positions. The pile pulling device according to claim 1, wherein the joint material is removed by a plate.

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