JP2002081066A - Pull-out method and device for foundation pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To pull out a pile without leaving any remnant by supporting the bottommost end of the pile even if an established pile is easily torn off due to corrosion and buckling, it is a splice pile, or the penetration is unknown and to effectively pull out without any use of a large-scale heavy machine in a densely built-up area. SOLUTION: A nozzle is arranged in a position surrounding a pile, high pressure water is diagonally downward jetted to lower the soil in the circumference of the pile while fluidizing it, a compressed air is jetted into the fluidized soil so as to reduce the nozzle lowering resistance and a pile pull-out resistance, and after detecting the lower end of the pile, it is pulled out by retaining the lower end of the pile. A nozzle and a retaining piece are fitted to a guide frame, the retaining piece is made to abut on the pile so as to lower it, the pile lower end is detected by separating from the pile surface to the lower part, and the pile lower end is retained by the retaining piece to be pulled up. The guide frame is lowered by a self traveling system. The retaining part of the lower end of the pile is pulled up by a wire rope.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for extracting an existing foundation pile buried underground.

[0002]

2. Description of the Related Art It is said that Japan is one of the world's leading earthquake nations, and that many buildings, such as buildings, are built on foundation piles, in combination with the fact that there are many soft ground layers. It is not an exaggeration. By the way, buildings such as buildings need to be dismantled because of their longevity, and further rebuilding to large ones, etc. In recent years, dismantling works have been particularly active in urban areas. At that time, the existing foundation piles are obstructed during the construction of the new building, and must be removed.

[0003] In order to pull out the existing foundation pile, the friction resistance between the soil around the pile and the pile is reduced by rotating the casing pipe along the leader while rotating the casing pipe with an earth auger supported by heavy equipment. It is common practice to raise piles. Japanese Unexamined Patent Application Publication No. 7-8 / 1995 discloses that by lowering a nozzle while injecting high-pressure water or compressed air, sediment is separated from the surface of a pile to facilitate pile pulling.
It is known from Japanese Patent No. 2744 and the like.

[0004] Japanese Patent Publication No. 3-57247 discloses that, for many years, a foundation pile buried in the soil has a reduced tensile strength due to corrosion or distortion and is torn off during drawing. Measures have been proposed. In other words, the casing is driven below the lower end of the pile, the soil surrounding the pile is muddy with water or bentonite, the locking projection is protruded from the lower end of the casing, and then the casing is pulled up. In this method, a lifting force is applied, and the upper end of the pile is gripped and pulled out with a fastening ring provided on the inner surface of the casing.

Further, Japanese Patent Application Laid-Open No. 11-193528 discloses that as a means for removing an existing pile having a joint pile structure, a projecting piece provided below a casing is projected by high-pressure water injection.
A construction method has been proposed in which the lower pile and the casing are pulled out together while being positioned at the lower end of the lower pile.

[0006]

In the case where an existing foundation pile is corroded or buckled on the way, or when a plurality of piles are joint piles, the above-mentioned Japanese Patent Publication No. Hei 3-5724 is used.
It is necessary to support and pull out the lowermost end of the pile by a construction method as proposed in Japanese Patent Application Laid-Open No. 7-193 and Japanese Patent Application Laid-Open No. 11-193528.

[0007] However, many existing foundation piles have a poor record at the time of construction due to the long elapsed period after casting, and there are many piles whose burial length is unknown. In such a case, it cannot be determined how far the casing should be lowered to reach the lowermost end,
The bottom end of the pile cannot be supported. For this reason, there is a possibility that a part of the pile may remain in the ground due to breakage during the lifting operation. In the event that a new pile is left behind and an obstacle occurs during the driving of the new pile, a great deal of labor and time is required, such as pulling out the new pile and excavating the remaining pile. In addition, it was difficult to use large-scale heavy equipment such as a densely-built building, which hindered the drawing operation and required a long period of time, and also had problems of vibration and dust generation.

The problem to be solved by the present invention is
Even if the existing foundation pile is easily broken due to corrosion, buckling, etc., or if it is a joint pile, or if the buried length is unknown,
To support the lowermost end of the buried pile and pull it out completely without removing it. In addition, in consideration of pollution problems such as vibration and dust generation, it is necessary to effectively pull out heavy-duty equipment in densely populated areas.

[0009]

According to the method of the present invention for solving the above-mentioned problems, a nozzle is arranged at a position surrounding a foundation pile buried underground, and high-pressure water is jetted obliquely downward from the nozzle. The nozzle is lowered while fluidizing the soil around the pile, and compressed air is blown into the fluidized soil to reduce the nozzle descent resistance and the pile pull-out resistance. It is a method of pulling out a foundation pile, which is characterized by pulling out.

In the method of the present invention, a guide frame is provided which descends from the surface of the foundation pile at an interval from the surface of the pile, and the nozzle and a holding piece which is in contact with the surface of the pile are attached to the guide frame. The lower end of the pile can detect the lower end of the pile by moving away from the surface of the pile, and the lower end of the pile can be held by the holding piece.

The guide frame can be lowered by providing a drive wheel and a pressing mechanism for the wheel. Furthermore, the foundation pile can be pulled out by attaching a wire rope to the holding portion that holds the lower end of the pile in advance and pulling up the wire rope by the wire clamp mechanism and the elevating mechanism.

According to another aspect of the present invention, there is provided a guide frame installed around a foundation pile buried underground at an interval from a surface of a pile, a lifting mechanism for the guide frame, and a guide frame. High pressure water jet nozzle, compressed air jet hole, pile bottom detector and pile bottom holding mechanism attached to
This is a device for pulling out a foundation pile, comprising a high-pressure water supply mechanism connected to the nozzle and a compressed air supply mechanism connected to the ejection hole.

In the apparatus of the present invention, the pile lower end detector includes a holding piece that descends while being in contact with the pile surface while being inclined, and a rotation mechanism that changes the inclination of the holding piece when the corresponding contact portion reaches the lower end of the pile. And the holding piece is attached to the guide frame via the rotating mechanism.

Further, a drive wheel and a pressing mechanism for the wheel may be attached to the guide frame, and the guide frame may have a mechanism for lowering the pile surface with the wheel as a track. Further, a wire rope is attached to the guide frame, and a wire clamp mechanism for clamping the wire rope, an elevating mechanism for elevating and lowering the wire clamp mechanism, a clamp and unclamping of the wire rope by the wire clamp mechanism, and an elevating movement by the elevating mechanism May be provided on the ground.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The prerequisites for pile removal work that the present inventors have learned through practical experience include (1) reduction of frictional force between a pile and soil, and (2) along the pile of a frictional force reduction device. (3) Detection of bottom of pile, (4) Holding of bottom of pile, (5)
Holding and pulling loose piles against the surrounding soil,
(6) Ensuring the resistance against buckling or cutting of the pile during pulling, and (7) Ensuring that the operation is pollution-free. And (1)
In order to reduce the frictional force, it was effective to use high-pressure water and compressed air together to fluidize the soil around the pile over the entire length of the pile.

Therefore, the method of the present invention fluidizes the soil around a foundation pile buried in the ground, reduces the frictional force between the pile and the soil, reduces the nozzle descent resistance and the pile pull-out resistance,
After detecting the lower end of the pile, it is a method of holding and pulling out the lower end of the pile. For fluidization and friction reduction around the pile, a nozzle is placed at the position surrounding the pile, high-pressure water is ejected from the nozzle diagonally downward, and the nozzle is lowered while fluidizing, and compressed air is injected into the fluidized soil. Spout out. The target foundation pile 1 can be applied to all kinds of foundation piles, for example, concrete piles, wooden piles, concrete piles, cast-in-place pedestal piles, franky piles, or steel pipes such as steel pipes and H-section steels. it can.

The method of the present invention will be described with reference to specific examples shown in the drawings. As shown in FIG. 1, the ground surface is dug down in advance to expose the upper end of the foundation pile 1, and a supporting column 3 which is slightly longer than the entire length of the pile 1 is supported by the heavy equipment 5 and set above the pile 1. I do. The guide frame 2 is attached to the lower end of the support column 3, and the guide frame 2 is provided with a nozzle 10 and a detection and holding mechanism for the lower end of the pile as shown in FIG.

The nozzle 10 is supplied with high-pressure water from a high-pressure water pump 6 through a hose 8 and a support column 3. A compressed air ejection mechanism is attached to the guide frame 2, and compressed air is supplied from the air compressor 7 through the hose 8 and the support pillar 3. In this example, the support column 3 is formed of two thick pipes, one for supplying high-pressure water and the other for supplying compressed air. 4 is a vibration generator, 9 is an upper end holding device.

After aligning the center of the guide frame 2 with the center of the foundation pile 1 by operating the heavy equipment 5, first, high-pressure water is jetted obliquely downward from the nozzle 10 as shown in FIG.
The nozzle 10 is piled up by lowering the guide frame 2
Lower along. In this example, four nozzles 10 are provided at approximately 90 ° intervals as shown in FIG. 2 and the center of the ejected high-pressure water flow is directed obliquely downward so that the center of the high-pressure water flow contacts the outer periphery of the pile 1. Flows around 1.

In the example of FIG. 3, the nozzle 10 is connected to the high-pressure water conduit 16.
Directly attached to. The conduit 16 is annular, and the nozzle 10 is mounted in an inner recess 19 as shown in FIG. 1
5 is a compressed air conduit. The compressed air conduit 15 or the high-pressure water conduit 16 can be used as the guide frame 2.

When the high-pressure water is ejected from the nozzle 10 in this manner, the high-pressure water flow penetrates the soil around the pile 1 and flows around the pile 1 while fluidizing. Since the high-pressure water flow has a downward vector, the separation and fluidization of the soil around the pile by the high-pressure water automatically proceeds downward.

When the nozzle 10 enters the soil and enters a depth of, for example, about 1 m, compressed air is sent into the fluidized soil. Then, most of the supplied air is dispersed in the fluidized soil and finally released into the air. The amount of compressed air continuously fed, the amount of air released from the fluidized soil around the pile 1 into the air, and the amount of air dispersed into the surrounding soil are finally balanced.

That is, macroscopically, it is considered that the amount of air sent in is distributed almost uniformly over the entire fluidized soil at a constant rate, which reduces the bulk density of the fluidized soil, The countless air particles existing in the fluidized soil have an important function of reducing the penetration resistance of the guide frame 2 to which the nozzle 10 and the lower end detection mechanism are attached in the soil, and further reducing the pull-out resistance at the time of removing the pile.

The compressed air is supplied to a compressed air conduit 15 provided in an annular shape above the high-pressure water conduit 16 as in the example shown in FIG.
Can be jetted from the compressed air jetting hole 17 provided directly in the nozzle. In this example, the compressed air is ejected obliquely upward. However, since the action of the compressed air is as described above, directivity in the ejecting direction is not particularly required. For this reason, a sufficient effect can be exhibited only by dispersing and opening the compressed air ejection holes 17 at substantially equal intervals around the circumference and the circumference of the annular compressed air conduit 15.

Even if the soil around the pile 1 is fluidized by the high-pressure water, the pressurization by the heavy equipment 5 is effective for allowing the device such as the nozzle 10 to enter the soil, and the vibration by the vibration generator 4 is not effective. Further, it is effective in reducing the entry resistance. What is important here is that the soil around the pile is fluidized and a large number of air particles are generated by blowing compressed air, so the vibration caused by the vibration is effectively attenuated and the vibration pollution around the construction site can be prevented. . Furthermore, because it is wet, there is no problem of dust generation,
The pollution-free operation is ensured.

In this way, the soil around the pile is fluidized over the entire length of the foundation pile 1 and the pulling resistance of the pile is reduced by air particles. Here, if the total length of the foundation pile 1 is known in advance from records at the time of construction, etc.,
May be set to be slightly longer than the total length of the foundation pile 1, but if it is not known, it can be set to the expected length, and if there is a shortage, it can be added during descent.

Here, the object of the present invention can be solved by reliably detecting the lower end of the pile even if the total length of the existing foundation pile 1 is unknown, and holding and pulling out the detected lower end. In this example, a holding piece 11 as in the examples of FIGS. 2 to 5 is employed as a mechanism for detecting and holding the lower end of the foundation pile 1. 2 is a plan view of the guide frame 2 as viewed from below, and FIGS. 3 to 5 are longitudinal sectional views. As shown in FIGS. 2 and 3, the holding piece 11 is, for example, in the form of four plates, the inscribed circle diameter at the tip of the holding piece is smaller than the outer diameter of the pile 1, and the mounting piece 11 is fixed to the guide frame 2. It is rotatably supported on a shaft 13. When the pile 1 is located above the upper end, the spring 14
The holding piece 11 is kept substantially horizontal by the spring force of.

As shown in FIG. 4, when the guide frame 2 descends around the pile 1, each holding piece 11 rotates in contact with the outer periphery of the pile 1 and rises obliquely upward. This rising is caused by the rotation detector 1
2 detected. Then, as shown in FIG.
When it reaches below the lower end of the stake 1, it rotates again to the horizontal position by the action of the spring 14, and the rotation is
Is detected by The holding piece 11 is locked by a locking piece 18 so as not to rotate downward.

When the rotation detector 12 detects that the holding piece 11 has rotated to the horizontal position, the operator can detect the lower end of the pile using a buzzer, a lamp, or the like. At this point, when the support column 3 is lifted by the heavy equipment 5,
The lower end of the pile is held by the holding piece 11, and the pile 1 is pulled out. At this time, the upper end of the pile is held by the upper end holding device 9 in the same manner as in the prior art, and the pile 1 is safely pulled out. The rotation detector 12 can be configured by a limit switch, a proximity switch, a photoelectric switch, or the like that is activated by rotation of the mounting shaft 13. The signal in this case can be guided to the ground by a cord provided along the support column 3 formed of a thick-walled tube or the like.

In this embodiment, since the four holding pieces 11 are arranged at intervals of about 90 °, the lower end of the pile is reliably detected, and the pulling load is dispersed. In addition, the buzzer and the lamp at the time of detecting the lower end are attached to the four holding pieces 11 respectively, and before entering the ground, the buzzer and the lamp corresponding to each of the four holding pieces 11 are set when the holding pieces 11 are in a horizontal state. By starting the approach after confirming that the lamp operates, reliability of the lower end detection can be obtained. That is, before reaching the bottom of the pile,
Even if the rotation detector 12 is activated due to a trouble with any one of the four holding pieces 11, it can be determined that the detection is not the lower end of the pile unless all four pieces are activated.

Next, a specific example of holding and removing the foundation pile 1 when pulling out the pile will be described. In FIG. 1, a wire (not shown) is spirally wound around the support column 3,
One end is fixed to the lower end of the support column 3, and the other end is held at the upper end of the support column 3. When the support pillar 3 is lowered along the foundation pile 1, the pile 1 is automatically wound by this wire. When the support pillar 3 is pulled up after the detection of the lower end of the pile and the holding of the lower end of the pile, the wire held at the upper end of the support pillar 3 is pulled, whereby the pile 1 and the support pillar 3 can be tightly bound by the wire. By pulling up the stake 1 to the ground and loosening the wire at the position where the stake 1 is removed from the support column 3, the stake 1 can be safely lowered to a predetermined position.

In the example of FIG. 1, the support column 3 is composed of two thick pipes, one for supplying high-pressure water and the other for supplying compressed air. It is also possible to supply. In this case, a check valve is provided at the connection between the high-pressure water hose and the compressed air hose, respectively.
Only one of the high-pressure water conduit 16 and the compressed air conduit 15 in FIGS.

The support column 3 may be of a split type. For example, a guide frame mounting portion, a vibration generator mounting portion, an upper end holding and hitting mounting portion, and a unit length (for example, 2
m), the intermediate portion having the same shape, and the intermediate portion being connected to have a required length according to the length of the pile 1, is compact and efficient when transporting and storing.

It is effective to improve the work efficiency by preparing several types of guide frames 2 according to the thickness of the foundation pile 1. Alternatively, the annular high-pressure water conduit 16 and the compressed air conduit 15 shown in FIG. 3 may be divided in the circumferential direction and assembled according to the outer diameter of the pile 1. In these cases, several types of holding pieces 11 are prepared, and one having an appropriate length according to the distance between the mounting portion and the pile 1 is selected. The guide frame 2 can be made of a sheet pile or a U-shaped steel. In this case, a conduit for supplying high-pressure water and compressed air is separately provided.

As a means for detecting the lower end of the pile, a method using eddy current is used when the foundation pile 1 is made of a metal such as a steel pipe or an H-section steel in which an iron material is put inside such as a concrete pile. You can also. For example, a penetrating coil having substantially the same outer diameter as the guide frame 2 is used as the detection end, and the lower end of the pile is detected by a change in eddy current when the coil falls below the lower end of the pile 1. Further, as the pile lower end holding mechanism, in addition to using four holding pieces 11 as shown in FIGS. 2 to 5, for example, one holding piece 11 as shown in FIG. 7 can be employed.

When the eddy current coil 20 is used as shown in FIG. 7, the holding piece 11 is set up so as not to come into contact with the stake 1 as shown by the broken line in FIG. After the lower end of the pile is detected by the coil 20, the hydraulic motor 22 can be used to tilt the pile as shown by the solid line in FIG.
Then, as shown in FIG. 7B, the tip of the holding piece 11 is held by the holding tool 21, and the pile 1 is supported and pulled up from below. In the example of FIG. 7 as well, a spring 14 is mounted on the mounting shaft 13 as shown in FIG. 2, and the holding piece 11 is brought into contact with the surface of the pile 1 while descending by using the spring force. It can be defeated by force as shown by the solid line.

When the holding piece 11 is used as the pile lower end detecting means, if the pulling device needs to be pulled up halfway for some reason, if the holding piece 11 is pressed against the pile 1 by the spring 14, the holding piece 11 is left as it is. I can't pull it up. In such a case, for example, as shown in FIG. 8, the tip of the wire 23 is fixed to the holding piece 11, and the wire 23 is pulled through the pulling-up spring 24 having a tension sufficiently larger than the tension of the pressing spring 14. Then, the holding piece 11 may be separated from the pile 1.

Next, in the method of the present invention, the guide frame 2 can be lowered by making the guide frame 2 self-propelled without using the support pillar 3 which rises above the ground. Examples are shown in FIG. 9 and FIG. For example, three drive wheels 26 are attached to the guide frame 2 at 120 ° intervals as shown in FIG. The drive wheel 26 is pivotally supported by a support rod 29 rotatably mounted on the guide frame 2 as shown in FIG. 9, and when the rod 28 of the hydraulic cylinder 27 is pulled up, the support rod 29 rotates and the drive wheel 26 Is pressed against the stake 1. The drive wheels 26 are driven to rotate by a hydraulic motor (not shown). The hydraulic pressure is supplied to the hydraulic cylinder 27 and the hydraulic motor from the ground via a hydraulic device 34.

As shown in FIG. 9, the driving wheel 26 is rotated while jetting high-pressure water from the nozzle 10 to fluidize the soil around the pile and jetting compressed air to reduce the frictional resistance of the fluidized soil. The rod 28 is pulled up by the hydraulic cylinder 27. Then, the guide frame 2 descends in a self-propelled manner with the surface of the pile 1 as a track while the three drive wheels 26 sandwich the pile 1. Then, when reaching the lower end of the pile, the rods 28 of the three cylinders 27 are all further contracted and hold the lower end of the pile. In this example, the drive wheel 26 functions as the holding piece 11. When the driving wheel 26 comes off the pile 1, the driving force of the wheel 26 is also lost at the same time, so that the device does not descend further. Therefore, the lower end of the pile is automatically detected and held.

After the lower end of the pile is held by the driving wheels 26, the wire rope 30 is wound up to pull up the guide frame 2 and the pile 1 as shown in FIG. Wire rope 30
Are attached to the guide frame 2 at two or three locations, and are wound on a winder 32 via a one-way stopper 33 and a reel 31. The one-way stopper 33 holds the wound wire rope 30 so as not to move downward, and furthermore, holds the wire 30.
It is also effective to add a mechanism for applying an upward force to the motor.

Further, in the method of the present invention, the wire rope 30 is previously attached to the holding portion for holding the lower end of the foundation pile 1, for example, the guide frame 2 as described above, and as shown in FIG. The foundation pile 1 can be pulled out by being pulled up by the wire clamp mechanism and the elevating mechanism. In the present embodiment, the wire clamp mechanism comprises a wire clamp cylinder 35, and the elevating mechanism comprises an elevating cylinder 36.

The lifting cylinder 36 is fixedly mounted on a base 38 on the ground surface, and raises and lowers a wire clamp cylinder 35 fixed on a platform 39. A pile clamp cylinder 37 is fixedly mounted on the gantry 38. FIG.
Has a wire rope 30, a wire clamp cylinder 3
5, lifting cylinder 36 and pile clamp cylinder 3
7 are shown two each, but if necessary, 3-4
It can be individual.

To pull out the pile 1, the wire rope 30 is clamped by the wire clamp cylinder 35, and the lifting cylinder 36 is raised to a predetermined position. After the pile 1 is held by the pile clamp cylinder 37, the wire rope 30 is unclamped by the wire clamp cylinder 35, and the lifting cylinder 36 is lowered to a predetermined position. Then, the wire rope 30 is clamped by the wire clamp cylinder 35 and the pile clamp cylinder 37 is clamped.
The stake 1 is unclamped to raise the elevating cylinder 36, and these are sequentially repeated. These series of operations are controlled by the controller 42.

In order to clamp the wire rope 30 with the wire clamp cylinder 35, wire clamps 40 and 41 are provided on the rod of the cylinder 35, and FIG.
2, the wire rope 30 is passed through the gap between the wire clamps 40 and 41. Wire clamp cylinder 35
When the rod is extended, the wire clamp 41 is pressed against the pile 1, and the wire rope 30 is firmly clamped between the wire clamps 40 and 41.

When the wire rope 30 is unclamped by the wire clamp cylinder 35 and the lifting cylinder 36 is lowered, it is more effective to wind the wire rope 30 with the winding machine 32 as shown in FIG. It is.
Further, the wire rope 30 may be held by another wire clamp cylinder or the like above the wire clamp cylinder 35, and in this case, the pile can be held without using the pile clamp cylinder 37. in this case,
The pulled-up wire rope 30 may simply be stored on the ground, for example, by forming a loop without using the winder 32.

Next, the apparatus of the present invention comprises a guide frame 2 as described in the above method of the present invention, its lifting mechanism,
High pressure water injection nozzle 10, compressed air jet hole 17, pile lower end detector and pile lower end holding mechanism attached to the nozzle, high pressure water supply mechanism connected to nozzle 10, and compressed air supply connected to jet hole 17 Mechanism.

The guide frame 2 comprises a foundation pile 1 buried underground.
It is installed at the center of the pile and at an interval from the pile surface. The lifting mechanism of the guide frame 2 is not only a heavy machine as in the example of FIG.
The self-propelled descent by the driving wheel 26 and the hoisting by the wire rope 30 as shown in FIGS. 9 and 10, or the clamp push-up by the wire clamp cylinder 35 and the elevating cylinder 36 as shown in FIG.

The lower end detector of the pile can be a holding piece 11 and its rotation detector 12 as shown in the examples of FIGS. 2 to 5 and 7, a vortex coil 20 as shown in FIG. 8, and the like. The pile lower end holding mechanism can be a holding piece 11 and its locking piece 18 as in the examples of FIGS. 2 to 5, and a holding piece 11 and a holding tool 21 as shown in FIGS. 7 and 8.

The high-pressure water supply mechanism comprises a high-pressure water pump 6 and a water supply path up to a nozzle 10 such as a hose 8 as shown in FIG. The compressed air supply mechanism includes an air supply path to the compressed air ejection hole 17 such as the air compressor 7 and the hose 8 as in the example of FIG. The detailed mechanism and operation of the device of the present invention are as described in the description of the method of the present invention.

[0050]

According to the present invention, in the demolition work of a building such as a building, the existing foundation pile can be pulled out safely and easily without pollution, and the pile is easily broken due to corrosion or buckling, or Even if it is a joint pile or the embedded length is unknown, the lowermost end of the embedded pile can be supported, and the entire length can be reliably pulled out without any removal. Furthermore, in a densely populated area, etc., it is also possible to effectively pull out without using a heavy equipment.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory diagram of the present invention.

FIG. 2 shows an example of a guide frame portion according to the present invention, and FIG.
FIG. 3 is a plan view taken along the line AA of FIG.

3 shows an example of a guide frame portion in the present invention, and FIG.
It is a longitudinal cross-sectional view corresponding to the BB arrow.

FIG. 4 is a longitudinal sectional view showing another example of the guide frame portion according to the present invention, which is equivalent to the view taken along the line BB of FIG. 2;

FIG. 5 is a longitudinal sectional view showing another example of the guide frame portion according to the present invention, corresponding to the view taken along the line BB of FIG. 2;

FIG. 6 is a plan view showing an example of mounting a nozzle according to the present invention.

FIG. 7 shows another example of holding the lower end of the pile according to the present invention,
(A) is a vertical sectional view taken along the line DD of (b), (b) is (a)
FIG. 5 is a cross-sectional view taken along the line CC in FIG.

FIG. 8 is a longitudinal sectional view showing an example of pulling up the device in the present invention.

FIG. 9 is a longitudinal sectional view showing another example of the guide frame portion in the present invention.

10 shows another example of the guide frame portion in the present invention, and is a plan view taken along the line EE in FIG.

FIG. 11 is an explanatory view showing an example of a pile pull-out mechanism in the present invention.

FIG. 12 is a horizontal sectional view showing an example of a pile pull-out mechanism in the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Pile 2 ... Guide frame 3 ... Support pillar 4 ... Vibration generator 5 ... Heavy machinery 6 ... High pressure water pump 7 ... Air compressor 8 ... Hose 9 ... Upper end holding device 10 ... Nozzle 11 ... Holding piece 12 ... Rotation detector DESCRIPTION OF SYMBOLS 13 ... Mounting shaft 14 ... Spring 15 ... Compressed air conduit 16 ... High pressure water conduit 17 ... Compressed air jetting hole 18 ... Locking piece 19 ... Concave 20 ... Eddy current coil 21 ... Holder 22 ... Hydraulic motor 23 ... Wire 24 ... Pulling up Spring 25 ... Ring 26 ... Drive wheel 27 ... Hydraulic cylinder 28 ... Rod 29 ... Support rod 30 ... Wire rope 31 ... Reel 32 ... Winding machine 33 ... One-way stopper 34 ... Hydraulic device 35 ... Wire clamp cylinder 36 ... Elevating cylinder 37: pile clamp cylinder 38: mount 39: platform 40, 41: wire clamp 42: control device

Claims (8)

[Claims] Claims 1. A nozzle is disposed at a position surrounding a foundation pile buried in the ground, and high-pressure water is jetted obliquely downward from the nozzle to lower the nozzle while fluidizing soil around the pile, A method for pulling out a foundation pile, comprising: ejecting compressed air into fluidized soil to reduce nozzle descent resistance and pile pull-out resistance; detecting a pile lower end; 2. A guide frame which descends at an interval from a pile surface around the foundation pile, and the nozzle and a holding piece which is in contact with the pile surface are attached to the guide frame, and the holding piece is separated from the pile surface. 2. The method according to claim 1, wherein the lower end of the pile is detected by moving downward, and the lower end of the pile is held by the holding piece. 3. The method according to claim 1, wherein a drive wheel and a pressing mechanism for the wheel are provided on the guide frame to lower the guide pile. 4. The foundation pile is pulled out by attaching a wire rope to a holding portion holding the lower end of the pile in advance, and pulling up the wire rope by a wire clamp mechanism and a lifting mechanism. 4. The method for pulling out a foundation pile according to 2 or 3. 5. A guide frame installed around a foundation pile buried in the ground at an interval from the surface of the pile, an elevating mechanism for the guide frame, a nozzle for jetting high-pressure water attached to the guide frame, A foundation pile pull-out device comprising an air ejection hole, a pile bottom detector, and a pile bottom holding mechanism, a high-pressure water supply mechanism connected to the nozzle, and a compressed air supply mechanism connected to the ejection hole. 6. The pile lower end detector comprises a holding piece that descends while being in contact with the pile surface while being inclined, and a rotating mechanism that changes the inclination of the holding piece when the contact portion reaches the lower end of the pile. 6. The device for pulling out a foundation pile according to claim 5, wherein the holding piece is attached to the guide frame via the rotating mechanism. 7. A driving wheel and a pressing mechanism for the wheel are attached to the guide frame, and the guide frame has a mechanism for descending the pile surface by using the wheel as a track. 6. The device for pulling out a foundation pile according to 6. 8. A wire clamp mechanism for attaching a wire rope to the guide frame, clamping the wire rope, raising and lowering the wire clamp mechanism, and clamping, unclamping and lifting the wire rope by the wire clamp mechanism. 6. A control device for controlling lifting and lowering by a mechanism is provided on the ground.
8. The device for pulling out a foundation pile according to 6 or 7.