Pile extracting method

Abstract

To provide a pile extracting device capable of pulling out a pile straight.SOLUTION: A pile extracting device 10 comprises a plate-shaped base 30 placed on the ground, an engagement portion 40 capable of engaging in the vertical direction with unevenness 102 formed on a pile 100, a jack 20 fixed on top of the base 30 and engaging with the pile 100 via the engagement portion 40 to push the pile 100 up from the ground, and slits 31, 41 formed in the base 30 and the engagement portion 40, respectively, into which the pile 100 fits so that the jack 20 can slide horizontally toward the pile 100.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a pile extraction device. [Background technology]

[0002] Conventionally, a single pipe clamp or a special metal fitting is attached to a pile buried in the ground, which is then engaged with a jack, and the pile is pulled out of the ground without bending by operating the jack. Such a pile extraction device is described, for example, on page 20 of the catalog shown in Non-Patent Document 1. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] "Kuimaru (registered trademark) catalog", [online], [searched on July 13, 2023], Internet<URL:https: / / www.kuimaru.com / pages / catalog.php> Summary of the Invention [Problem to be solved by the invention]

[0004] However, when a pile extractor such as a jack is placed on soft ground, a part of the pile extractor may sink into the ground due to a reaction force when pulling out a pile, causing the pile extractor to tilt relative to the pile. In this case, it becomes difficult to pull out the pile, and in some cases the pile may even be bent.

[0005] The present invention has been made in consideration of the above problems, and an object of the present invention is to provide a pile extraction device that can pull out a pile straight. [Means for solving the problem]

[0006] The means for solving the above problem is a pile extraction device for pulling out a pile from the ground, comprising a plate-shaped base installed on the ground, an engaging portion capable of engaging with the engaged portion of the pile in the vertical direction, a jack fixed to the top of the base and engaging the pile with the engaging portion to push the pile up from the ground, and slits formed in the base and the engaging portion, into which the pile can be inserted so that the jack can be slid horizontally toward the pile.

[0007] The jack is fixed onto a plate-shaped base, and the base has a wider area of ​​surface contact with the ground than the jack, so that when the pile is pushed up from the ground, it can be pulled out stably without sinking into the ground.

[0008] However, if the jack and the pile are separated, force is applied to the engagement part that engages with the pile, which may cause the engagement part to bend and make it difficult to transmit force to the pile. Also, if the pile is tilted relative to the jack, it may also become difficult to transmit force from the engagement part to the pile, causing the pile to bend.

[0009] Therefore, slits are formed in the base and the engagement part so that the pile can be guided close to the jack. This makes it easier to place the pile close to the jack and transmit force from the engagement part to the pile. As slits are also formed in the engagement part, the pile can be positioned above and below, and tilting of the pile relative to the jack can be prevented. In addition, as the slits can be slid horizontally, it is easy to guide the pile close to the jack regardless of the length of the pile. [Brief description of the drawings]

[0010] [Figure 1] FIG. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4]FIG. 4 is a front view of the pile extraction device when the jack is extended in the vertical direction. [Diagram 5] Plan view of the pedestal. [Figure 6] FIG. 13 is a plan view of the engagement portion when the pile is placed. [Figure 7] 1A is a side view of the pile extraction device in an initial state, FIG. 1B is a side view of the pile extraction device when the pile is guided into the slit, and FIG. 1C is a side view of the pile extraction device when pushing up the pile. [Figure 8] Side view of a pile in deformation. [Figure 9] FIG. [Figure 10] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the "pile extraction device" according to the present invention will be described with reference to the drawings. In the following embodiments and modifications, the same reference numerals are used in the drawings to designate the same or equivalent parts, and the explanations of the parts with the same reference numerals are incorporated herein. In addition to the combinations of the configurations explicitly shown in the description of the embodiments and modifications, it is also possible to combine the embodiments and modifications as long as there is no particular problem with the combination.

[0012] The pile extraction device 10 shown in FIG. 1 is a device for extracting a pile 100 from the ground. The pile 100 is formed in a metal rod shape. The shape of the pile 100 may be any shape as long as it is long, and may be a steel pipe. A metal fitting 101 (see FIG. 8(a) and the like) such as an orthogonal clamp, a free clamp, or a single pipe clamp can be attached to the pile 100. In addition, the tip of the pile 100 (the part that is protruded from the ground) may be provided with a flange-shaped unevenness 102 as shown in FIG. 8(b). In the following, these will be collectively referred to as an engaged part 103 of the pile 100.

[0013] 1 to 3, the pile extraction device 10 includes a jack 20 for pushing up a pile 100 from the ground, a base 30 to which the jack 20 is fixed, and an engaging part 40 that is fixed to the jack 20 and engages with the pile 100. For ease of explanation, the engaged part 103 of the pile 100 is not shown in FIG. 1.

[0014] The jack 20 is a well-known pantograph jack, and includes a base 21, a diamond-shaped arm portion 22 rotatably fixed to the base 21, and a load receiving portion 23.

[0015] The arm section 22 is composed of a pair of lower arms 22a, 22b and a pair of upper arms 22c, 22d. The lower arms 22a, 22b and the upper arms 22c, 22d are formed to be approximately the same length. The first ends of the lower arms 22a, 22b are rotatably fixed to the base 21, and the lower arms 22a, 22b are rotatable in a predetermined direction (the direction in which the arm section 22 extends). The first ends of the upper arms 22c, 22d are rotatably fixed to the second ends of the lower arms 22a, 22b. The second ends of the upper arms 22c, 22d are rotatably fixed to the load receiving section 23.

[0016] As a result, as shown in Figures 2 and 4, by extending the arm portion 22 in the vertical direction, the base 21 and the receiving portion 23 can be moved away from each other, and by extending the arm portion 22 in the horizontal direction (the horizontal direction in Figures 2 and 4), the base 21 and the receiving portion 23 can be brought closer to each other.

[0017] A threaded rod 24 is stretched between a first joint portion where the lower arm 22a and the upper arm 22c are connected, and a second joint portion where the lower arm 22b and the upper arm 22d are connected. A first end of the threaded rod 24 is rotatably fixed via a bearing 25 provided at the second joint portion. A square pillar 24a is formed at the tip of the first end side of the threaded rod 24, and the threaded rod 24 can be rotated by turning the square pillar 24a with a wrench or the like. The tip shape of the first end side of the threaded rod 24 can be arbitrarily changed, and may be formed into a hexagonal pillar shape or a ring shape.

[0018] A male screw is provided on the second end of the threaded rod 24, and is adapted to screw into a female screw provided on the first joint portion. As a result, when the threaded rod 24 is rotated in a predetermined direction, the arm portion 22 is extended in the vertical direction, and the base 21 and the goods receiving portion 23 can be moved away from each other, and when the threaded rod 24 is rotated in the opposite direction, the arm portion 22 is extended in the left-right direction (horizontal direction), and the base 21 and the goods receiving portion 23 can be moved closer to each other.

[0019] 3, the base 21 of the jack 20 is provided with wide portions 21a on both sides in a first direction (corresponding to the up-down direction in FIG. 3) in which the arm portion 22 extends, the wide portions 21a having a width that increases in a second direction (corresponding to the left-right direction in FIG. 3) perpendicular to the first direction. In other words, the base 21 of the jack 20 is provided with a narrow portion 21b having a narrow width in the second direction in the center in the first direction.

[0020] The base 30 is formed of a substantially square metal plate, and the base 21 of the jack 20 is fixed onto the base 30 by welding or the like. In this embodiment, the vertical dimension of the base 30 is 200 mm, and the horizontal dimension is 200 mm. The thickness dimension of the base 30 is about 2 mm to 5 mm. Note that each dimension of the base 30 may be changed as desired, and the base 30 may be rectangular.

[0021] The method of fixing the jack 20 is arbitrary, and the jack 20 may be fixed by screws, adhesive, etc. The area of ​​the lower surface of the base 30 (the surface that contacts the ground) is larger than the area of ​​the bottom surface of the base 21 of the jack 20. The base 21 of the jack 20 is fixed near the center of the base 30.

[0022] However, if the base 21 of the jack 20 is fixed near the center of the base 30, the distance from the jack 20 to the outer edge of the base 30 becomes long, and if this continues, it will be necessary to lengthen (enlarge) the engagement part 40 that engages with the pile 100. If the engagement part 40 becomes long, a force will be applied to the engagement part 40 that engages with the pile 100, and it may bend, making it difficult to transmit the force to the pile 100, or the engagement part 40 may bend.

[0023] Therefore, a slit 31 is formed in the base 30 to guide the pile 100 closer to the jack 20 so that the jack 20 can be slid toward the pile 100 in the horizontal direction. The slit 31 is formed to be recessed horizontally toward the base 21 of the jack 20, and the pile 100 is inserted into the slit 31. As shown in FIG. 5, the slit 31 in the base 30 is formed to be recessed straight from the outer edge of the base 30 toward the jack 20. The width dimension L11 of the slit 31 is larger than the diameter of the pile 100 (for example, 48.6 mm), and is formed to be, for example, about 52 mm. The depth dimension L12 from the opening of the slit 31 is larger than the diameter of the pile 100, and is formed to be, for example, about 65 mm. The side of the base 21 (rear side) of the slit 31 is a semicircular (arc-shaped) notch with a radius of about 26 cm according to the outer diameter of the pile 100.

[0024] In a plan view of the pile extraction device 10, that is, when the pile extraction device 10 is viewed from above, the slits 31 of the base 30 are provided to extend in a second direction perpendicular to the first direction in which the arm portion 22 extends, as shown in Fig. 3. In addition, in a plan view, the slits 31 of the base 30 extend to between a pair of wide portions 21a provided on both sides of the base 21 in the first direction (that is, to the vicinity of the narrow portions 21b of the base 21).

[0025] The engagement portion 40 is fixed to the load receiving portion 23 of the jack 20. The fixing method may be any method such as welding, adhesive, or screwing. The engagement portion 40 is formed in a plate shape of 10 cm x 10 cm, and is provided so as to protrude horizontally from the load receiving portion 23. Specifically, it is provided so as to protrude from the load receiving portion 23 in the same direction as the direction of the slit 31 of the base 30. In this embodiment, the size of the engagement portion 40 is smaller than the size of the base 30, but the various dimensions and shapes of the engagement portion 40 may be changed as desired.

[0026] Similarly to the base 30, the engagement part 40 is also provided with a slit 41 into which the pile 100 fits so that the jack 20 can be slid toward the pile 100 in the horizontal direction. As shown in FIG. 6(a), the slit 41 of the engagement part 40 is formed in a tip 42 that protrudes from the load receiving part 23 of the jack 20, and is formed so as to be recessed in the same direction as the slit 31 formed in the base 30. Therefore, the tip 42 of the engagement part 40 is divided into two and has a claw shape.

[0027] Similarly to the base 30, the slit 41 of the engagement part 40 is formed to be recessed straight toward the jack 20. The pile 100 is guided into the slit 41 of the engagement part 40, and is positioned so that the pile 100 is sandwiched between the two divided tip parts 42.

[0028] The width dimension L21 of the slit 41 of the engagement portion 40 is slightly larger than the diameter of the pile 100 (e.g., 48.6 mm), and is formed to be, for example, about the same as the width dimension L11 of the slit 31 of the base 30 (52 mm). Note that the width dimension L21 of the slit 41 may be changed arbitrarily as long as the tip portion 42 can be engaged with the engaged portion 103 of the pile 100 in the up-down direction when the pile 100 is guided into the slit 41. Also, the depth dimension L22 of the slit 41 from the opening is larger than the radius of the pile 100, and is formed to be, for example, about 30 mm.

[0029] Furthermore, when viewed in a plan view of the pile extraction device 10, i.e., when viewed from above, as shown in Figure 3, each slit 31, 41 is provided so that the rear end of the slit 41 of the engagement portion 40 is positioned at the same position as the rear end of the slit 31 of the base 30.

[0030] Next, a method of using the thus-formed pile extraction device 10 will be described.

[0031] First, the threaded rod 24 is rotated to extend the arm portion 22 in the left-right direction, bringing the base 21 and the load receiving portion 23 closer to each other, and the jack 20 is set to the initial state. The initial state refers to the state in which the arm portion 22 is retracted and the base 21 and the load receiving portion 23 are closest to each other, as shown in FIG.

[0032] Then, the openings of the slit 31 of the base 30 and the slit 41 of the engagement portion 40 are directed toward the pile 100 embedded in the ground. Then, as shown in Fig. 7(a), the pile extraction device 10 is moved horizontally to guide the pile 100 into the slits 31, 41, and the pile extraction device 10 is moved until the pile 100 is positioned near the jack 20 as shown in Fig. 1. Then, as shown in Fig. 6(b) and Fig. 7(b), the tip portion 42 of the engagement portion 40 is positioned below the engaged portion 103 of the pile 100.

[0033] Then, the threaded rod 24 is rotated to vertically engage the tip 42 of the engaging portion 40 with the engaged portion 103 of the pile 100 from below, thereby extending the arm portion 22 in the vertical direction. From this state, the threaded rod 24 is further rotated, and the engaged portion 103 of the pile 100 is pushed up by the engaging portion 40 as shown in Fig. 7(c), and the pile 100 is pushed up and pulled out of the ground.

[0034] With the above-described configuration, the present embodiment provides the following advantages.

[0035] The jack 20 is fixed onto a flat base 30, and the base 30 has a wider surface contact with the ground than the base 21 of the jack 20. Therefore, when the pile 100 is pushed up from the ground, it can be pulled out stably without being buried in the ground.

[0036] However, if the jack 20 and the pile 100 become separated from each other, force is applied to the engaging portion 40 that engages with the engaged portion 103 of the pile 100, which may cause the engaging portion 40 to bend and become difficult to transmit force to the pile 100, or the engaging portion 40 to bend. Also, if the pile 100 is tilted relative to the jack 20, it may also become difficult to transmit force from the engaging portion 40 to the pile 100, causing the pile 100 to bend.

[0037] Therefore, the slits 31, 41 into which the pile 100 enters are formed in the base 30 and the engagement part 40, respectively, so that the jack 20 can be slid toward the pile 100 in the horizontal direction. That is, the slits 31, 41 for guiding the pile 100 to the vicinity of the jack 20 are formed in the base 30 and the engagement part 40, respectively. This makes it easier to transmit force from the engagement part 40 to the pile 100 by disposing the pile 100 near the jack 20. Since the slits 41 are also formed in the engagement part 40, the pile 100 can be positioned above and below, and the pile 100 can be prevented from tilting relative to the jack 20. In addition, since the slits 31, 41 allow the pile extraction device 10 to slide horizontally relative to the pile 100, the pile 100 can be easily guided to the vicinity of the jack 20 regardless of the length of the pile 100.

[0038] The slit 31 in the base 30 is formed to be recessed horizontally toward the base 21 of the jack 20, and is a slit that guides the pile 100 close to the base 21 of the jack 20. In addition, the slit 41 in the engagement part 40 is formed in the tip part 42 of the engagement part 40 that protrudes from the load receiving part 23 of the jack 20, and is recessed in the same direction as the slit 31 formed in the base 30. By moving the pile extraction device 10 in a predetermined direction, it is possible to guide the pile 100 deep into the slits 31, 41.

[0039] In addition, the pile 100 can be arranged so that it is sandwiched between the divided tip portions 42 by being guided into the slits 41 of the engagement portion 40. By sandwiching the pile 100 at two points, top and bottom, it is possible to prevent the pile 100 from tilting relative to the pile extraction device 10.

[0040] 6(b), the engaging portion 40 has its tip 42 engaging with the engaged portion 103 of the pile 100 at two locations spaced apart from each other around the pile 100 in the horizontal direction. Therefore, when pushing up the pile 100, force can be applied from both sides to stably push it up, and tilting of the pile 100 can be prevented. In addition, the contact area between the engaging portion 40 and the engaged portion 103 of the pile 100 increases, so force can be applied stably.

[0041] 6(b), by guiding the pile 100 to the back of the slit 31, the engaged part 103 can be engaged with the main body of the engaging part 40. This increases the contact area between the engaging part 40 and the engaged part 103 of the pile 100, allowing for stable application of force.

[0042] In the slit 31 of the base 30, the depth dimension L12 from the opening is larger than the diameter of the pile 100. As a result, when the pile 100 is guided close to the jack 20, that is, when the pile 100 is pushed up, the base 30 can be arranged so as to reach the opposite side of the pile 100. In other words, when the pile 100 is arranged close to the jack 20, the base 30 can be arranged so as to extend from the jack 20 to the other side of the pile 100 (the side where the jack 20 is not arranged). As a result, when the pile 100 is pulled out, the base 30, more specifically, the parts of the base 30 arranged on both sides of the slit 41 can effectively prevent the jack 20 from tilting toward the pile 100.

[0043] Similarly, in the slit 41 of the engaging portion 40, the depth dimension L22 from the opening is larger than the radius of the pile 100. This makes it possible to increase the contact area between the engaged portion 103 and the engaging portion 40, particularly the tip portion 42 of the engaging portion 40, and thus allows for stable pushing up.

[0044] Furthermore, by using a pantograph jack as the jack 20, the pile extraction device 10 can be realized with a simpler structure than a hydraulic jack or the like.

[0045] 3, in a plan view, the rear end of the slit 31 of the base 30 and the rear end of the slit 41 of the engagement part 40 are at the same position. That is, in the second direction, the position of the rear end of the slit 31 of the base 30 and the position of the rear end of the slit 41 of the engagement part 40 are aligned. At the same time, the shape of the rear end of the slit 31 of the base 30 and the rear end of the slit 41 of the engagement part 40 are semicircular in accordance with the outer shape of the pile 100. This makes it possible to slide the pile puller 10 until the pile 100 abuts against the semicircular portion at the rear end of the slits 31, 41, and the pile 100 can be securely held by the slits 31, 41.

[0046] In a plan view, the slits 31 and 41 each extend in a second direction perpendicular to the first direction in which the arm portion 22 extends. In addition, in a plan view, the slits 31 and 41 each extend to between the wide portions 21a disposed on both sides in the first direction. This allows the pile 100 to be firmly supported on both sides in the first direction when the pile 100 is pushed up by the jack 20.

[0047] (Modification) A portion of the configuration of the pile puller 10 of the above embodiment may be modified as described below. Below, a modified example in which a portion of the configuration of the pile puller 10 is modified will be described.

[0048] In the above embodiment, the width dimension of the opening side of the slit 31 of the base 30 may be made wider than the width dimension of the base 21 side of the jack 20. For example, as shown in Fig. 9, the opening 32 of the slit 31 may be made wider. Similarly, the opening of the slit 41 of the engagement part 40 may be made wider. This makes it easier to guide the pile 100 into the inside of the slits 31, 41 when sliding it.

[0049] In the above embodiment, the slits 31, 41 are formed so as to be recessed straight toward the jack 20, but the shape of the slits 31, 41 may be changed as desired. For example, the slits 31, 41 may be bent in an L-shape.

[0050] In the above embodiment, the rear end of the slit 31 of the base 30 and the rear end of the slit 41 of the engagement portion 40 do not have to be at the same position in a plan view.

[0051] In the above embodiment, the two-part tip portion 42 of the engaging portion 40 engages with the engaged portion 103 of the pile 100, but it may engage with the base end portion of the engaging portion 40. In other words, the pile 100 may be engaged with the engaging portion 40 by inserting it all the way into the slit 41. This increases the number of engagement points, making it possible to pull out the pile 100 more stably.

[0052] In the above embodiment, a guide wall may be provided that stands on the base 30 and surrounds at least a part of the slit 31 of the base 30. For example, as shown in Fig. 10, a guide wall 35 may be provided that stands so as to surround the periphery of the slit 31. This makes it possible to prevent the pile 100 from tilting when the pile 100 is guided into the slit 31 by the guide wall 35.

[0053] In the above embodiment, the jack 20 is a screw type jack, but other jacks may be used, for example, a hydraulic jack or an air jack. The shape of the jack 20 is not limited to a pantograph jack and may be changed as desired. For example, a floor jack may be used.

[0054] In the above embodiment, the shape of the slits 31, 41 may be changed as desired. For example, the semicircular notch may not be formed on the inner side of the slits 31, 41. Also, the shape of the slit 41 of the engagement portion 40 and the shape of the slit 31 of the base 30 may be different. [Explanation of symbols]

[0055] 10...pile extraction device, 20...jack, 21...base, 22...arm portion, 22a, 22b...lower arm, 22c, 22d...upper arm, 23...load receiving portion, 24...threaded rod, 30...base, 31...slit in base 30, 40...engagement portion, 41...slit in engagement portion, 42...tip portion, 100...pile, 103...engaged portion.

Claims

1. A pile extraction device for extracting piles from the ground, A plate-shaped base that is placed on the ground, An engaging portion that can be engaged with the engaged portion of the pile in the vertical direction; A jack that is fixed on the base and engages the pile with the engagement portion to push the pile up from the ground; A pile extraction device comprising a slit formed in each of the base and the engagement portion, into which the pile can be inserted so that the jack can be slid horizontally toward the pile.

2. The slit of the base is formed to be recessed toward the base of the jack in the horizontal direction, and is a slit that guides the pile close to the base of the jack, The slit of the engagement portion is formed at a tip portion of the jack protruding from the load receiving portion, and is a slit recessed in the same direction as the slit formed in the base, The pile extraction device according to claim 1 , wherein the pile is guided into the slits of the engagement portion so that the pile is sandwiched between the multiple branched tip portions.

3. The pile extraction device according to claim 2 , wherein, in a plan view, a rear end portion of the slit of the base and a rear end portion of the slit of the engagement portion are positioned at the same position.

4. The pile extraction device according to any one of claims 1 to 3, wherein a depth dimension from the opening of the slit in the base is larger than a diameter of the pile.

5. The pile extraction device according to any one of claims 1 to 3, further comprising a guide wall erected on the base and surrounding at least a portion of the slit in the base.

6. The jack is a pantograph jack that has a diamond-shaped arm and changes its height by rotating a screw rod disposed at the center of the arm, In a plan view, the slits of the base and the engagement portion each extend in a second direction perpendicular to a first direction in which the arm extends, The base of the jack to which the arm is attached has a wide portion on each side in the first direction, the wide portion having a width that increases in the second direction, The pile extraction device according to any one of claims 1 to 3, wherein the slit in the base extends to between the wide portions in a plan view.

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