Steel pipe pile driving tool, steel pipe pile with excavation wings, and method for driving steel pipe piles

Abstract

The present invention provides a steel pipe pile driving tool, a steel pipe pile with excavation wings, and a steel pipe pile driving method that minimize disturbance to the surrounding soil of the steel pipe shaft in a steel pipe pile, and minimize wear during excavation. [Solution] The steel pipe pile driving tool 1 is a driving tool for driving a steel pipe pile with excavation wings 3, which has an excavation wing 32 on the tip side of the shaft steel pipe 31, into the ground 4. The driving tool 1 is insertable into and removes from the shaft steel pipe 31 and includes an insertion rotating part 11 that rotates inside the shaft steel pipe 31 when inserted, a rotation transmission part 12 provided on the tip side of the insertion rotating part 11 that fits into the center of the excavation wing 32 and transmits the rotation of the insertion rotating part 11 to the excavation wing 32, and a movement force applying part 5 that applies the movement force of the insertion rotating part 11 in the direction of penetration to the rear end side of the shaft steel pipe 31.

Description

Technical Field

[0001] This invention relates to a steel pipe pile with excavation blades used for ground improvement, a driving tool for driving this steel pipe pile into the ground, and a method for driving the steel pipe pile.

Background Art

[0002] Conventionally, in the improvement construction of soft ground, a steel pipe pile with excavation blades (fins) has been developed that facilitates the penetration of the steel pipe pile by applying rotation to the steel pipe pile and can increase the supporting force of the steel pipe pile in the ground after construction.

[0003] Furthermore, Patent Document 1 discloses a method of rotationally pressing a casing into the ground, the casing comprising a first fin (excavation blade) fixed to the casing body, a second fin (excavation blade) detachably engaged with the casing body, and a hook mechanism for engaging the second fin with the casing body. A steel pipe pile inserted into the casing body is inserted into the second fin, the hook mechanism is released to release the second fin from the casing body, and while leaving the second fin and the steel pipe pile in place, the casing body is pulled out and the space between the casing body and the steel pipe pile is backfilled with earth and sand.

[0004] Also, Patent Document 2 discloses an excavation rod comprising a rod body, an excavation head (excavation blade), and a connecting rod vertically connected between the rod body and the excavation head. The excavation head has a first shaft portion and a horizontal protrusion provided below the upper end (rear end) of the first shaft portion and protruding radially outward from the outer peripheral surface of the first shaft portion. The connecting rod has a cylindrical second shaft portion into which the first shaft portion can be inserted and a plate-like downward protrusion extending vertically downward from a position radially outside the second shaft portion to a position below the horizontal position where the lower end of the second shaft portion is located.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2013-151850 [Patent Document 2] Patent No. 7320315 Publication [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, the conventional steel pipe pile installation method and excavation head described above involve penetrating the ground with a casing (guide rod) that has an inner diameter larger than the outer diameter of the steel pipe shaft. This significantly disturbs the ground around the steel pipe shaft and removes soil, potentially making buildings more susceptible to shaking from earthquakes or traffic vibrations compared to ground improved using general steel pipe pile construction methods. Furthermore, although the casing is equipped with wings (second fins) to compact the disturbed ground and fill in the removed soil, it is uncertain whether the greatly disturbed ground will be sufficiently compacted and whether soil will be filled along the entire length of the steel pipe shaft. In addition, since the casing excavates the ground when the steel pipe shaft is driven, there is the drawback that the casing wears down with each excavation.

[0007] In view of the above circumstances, this invention aims to provide a driving tool, a steel pipe pile with excavation wings, and a method for driving steel pipe piles that are less likely to cause disturbance to the soil surrounding the shaft steel pipe of a steel pipe pile, and that are less likely to cause wear during excavation. [Means for solving the problem]

[0008] The steel pipe pile driving tool according to this invention is a driving tool for driving a steel pipe pile with drilling wings into the ground, in which drilling wings are fitted to the tip side of the shaft steel pipe without being fixed to the shaft steel pipe, in order to solve the above problems, and is characterized by comprising: an insertion and rotation part that can be inserted into and removed from the shaft steel pipe and rotates inside the shaft steel pipe when inserted; a rotation transmission part provided on the tip side of the insertion and rotation part, which fits into the center of the drilling wings and transmits the rotation of the insertion and rotation part to the drilling wings; and a movement force applying part that applies a movement force in the direction of penetration to the rear end side of the shaft steel pipe.

[0009] With the above configuration of the driving tool, the insertable rotating part is inserted into the shaft steel pipe, and the steel pipe pile with excavating wings is rotated to excavate the ground. Therefore, the ground around the shaft steel pipe is not significantly disturbed, and no soil is removed. Consequently, there is no need to compact the disturbed ground or fill in the removed soil. Also, since it is the steel pipe pile that contacts the ground, the driving tool does not wear down with each excavation. Furthermore, the rotational force from the rotating lifting part of the driving machine is not transmitted from the shaft steel pipe to the excavating wings, but from the insertable rotating part of the driving tool to the excavating wings. Moreover, the excavating wings are not fixed to the shaft steel pipe but are rotatably fitted, and the shaft steel pipe is not forcibly rotated by the rotation of the excavating wings during excavation, so the shaft steel pipe is less likely to experience torsional stress. For this reason, it becomes easy to reduce the size of the shaft steel pipe (smaller diameter and thinner) to suppress ground improvement costs. Furthermore, even if the drilling blade is not fixed to the shaft steel pipe, the moving force-applying unit provides a moving force in the direction of penetration to the rear end of the shaft steel pipe, allowing the shaft steel pipe to penetrate the ground.

[0010] The rear end of the above-mentioned insertable rotating part has a protrusion that extends from the above-mentioned shaft steel pipe, and the above-mentioned movable force applying part may be attached to the outer circumference of this protrusion.

[0011] The above-mentioned movable force-applying part may be an insertion member that is inserted into a hole formed in the outer circumferential surface of the protruding part, protrudes from the outer circumferential surface, and contacts the rear end of the shaft steel pipe.

[0012] The above-mentioned movable force-applying portion may be a flange-shaped member that is engaged with a circumferential recess formed on the outer surface of the protruding portion, protrudes from the outer surface, and contacts the rear end of the shaft steel pipe.

[0013] The above-mentioned movable force-applying portion may be an annular pressure-contacting member that is pressed against the outer circumferential surface of the protruding portion, protrudes from the outer circumferential surface, and contacts the rear end of the shaft portion steel pipe.

[0014] Furthermore, the steel pipe pile of this invention is a steel pipe pile with an excavation wing, wherein the excavation wing is rotatably fitted to the tip side of the shaft steel pipe without being fixed to the shaft steel pipe, and the excavation wing has a receiving fitting portion in the center of the excavation wing into which the rotation transmission portion of the driving tool is fitted.

[0015] In the case of the steel pipe pile described above, the rotation of the insertion rotating part of the driving tool is received by the receiving fitting part from the rotation transmission part, thereby rotating the excavation blade. Compared to a structure in which the excavation blade is rotated by the shaft steel pipe, the torsional load on the shaft steel pipe can be reduced. Furthermore, because the excavation blade is not fixed to the shaft steel pipe but is rotatably fitted, and the shaft steel pipe is not forcibly rotated by the rotation of the excavation blade during excavation, the shaft steel pipe is less likely to experience torsional load. For this reason, it becomes easier to reduce the size of the shaft steel pipe (smaller diameter and thinner thickness) to suppress ground improvement costs.

[0016] In the steel pipe pile described above, a fitting riser is formed on the outer peripheral wall portion outside the central part of the excavation blade, rising inward from the outer peripheral wall portion. The fitting riser is fitted into the shaft steel pipe, and the lateral movement of the shaft steel pipe during rotation of the excavation blade may be restricted by the fitting riser. This prevents the shaft steel pipe from coming laterally detached from the excavation blade.

[0017] An outer rising portion is formed that rises outside the outer peripheral wall portion, and the shaft steel pipe may be fitted between the outer rising portion and the fitting rising portion. This makes it possible to more reliably prevent the shaft steel pipe from coming off laterally.

[0018] In addition, the method for driving the steel pipe pile of this invention includes a step of inserting the insertion and rotation part in the driving tool into the shaft steel pipe in the steel pipe pile with excavation blades, and fitting the rotation transmission part to the center part of the excavation blades; a step of attaching the rear end side of the insertion and rotation part to the rotation and lifting part of the driving machine; a step of lowering the rotation and lifting part to apply a moving force in the penetration direction to the rear end side of the shaft steel pipe by the moving force applying part while rotating the excavation blades, thereby penetrating the steel pipe pile with excavation blades into the ground; and a step of extracting the driving tool from the shaft steel pipe.

[0019] According to the above method, the ground around the shaft steel pipe is not greatly disturbed, and there is no need to remove soil. Therefore, there is no need to compact the disturbed ground or fill the removed soil. Also, since it is the steel pipe pile that contacts the ground, the driving tool does not wear during each excavation. Furthermore, since the shaft steel pipe is less likely to be subjected to torsional load, it is easy to reduce the size of the shaft steel pipe.

Advantages of the Invention

[0020] In the case of this invention, the soil around the shaft steel pipe in the steel pipe pile is less likely to be disturbed, and the driving tool is less likely to wear during excavation. Furthermore, since the shaft steel pipe is less likely to be subjected to torsional load, various effects such as being able to reduce the size of this shaft steel pipe and suppress the ground improvement cost can be achieved.

Brief Description of the Drawings

[0021] [Figure 1] It is an explanatory drawing showing the driving tool, steel pipe pile, and driving method of the embodiment. [Figure 2] It is a partially broken explanatory drawing showing the driving tool having the moving force applying part of the embodiment and the steel pipe pile with excavation blades in perspective. [Figure 3] It is an explanatory drawing showing an enlarged view of the rotation transmission part of the steel pipe pile with excavation blades in FIG. 2. [Figure 4] It is an explanatory drawing showing a modified example of the driving tool having the moving force applying part of the embodiment and the steel pipe pile with excavation blades. [Figure 5]FIGS. (A) and (B) are explanatory views showing a modified example of a placer having a moving force applying portion according to an embodiment and a steel pipe pile with excavation blades, respectively. [Figure 6] It is an explanatory view showing a modified example of a placer having a moving force applying portion according to an embodiment and a steel pipe pile with excavation blades. [Figure 7] It is an explanatory view showing an enlarged view of the excavation blade connection portion of the steel pipe pile with excavation blades according to another embodiment. [Figure 8] It is an explanatory view showing an example of an operation of inserting and raising a placer having a moving force applying portion according to an embodiment into a steel pipe pile with excavation blades. [Figure 9] It is an explanatory view showing an example of an operation of inserting and raising a placer having a moving force applying portion according to an embodiment into a steel pipe pile with excavation blades.

MODE FOR CARRYING OUT THE INVENTION

[0022] Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. As shown in FIG. 1, the placer 1 according to the embodiment includes an insertion rotation portion 11 and a rotation transmission portion 12, and is mounted on the rotation lifting portion 21 of the placer 2 and used to penetrate the steel pipe pile 3 with excavation blades into the ground 4. The steel pipe pile 3 with excavation blades has, for example, spiral excavation blades 32 on the tip side (end portion on the ground side) of the shaft steel pipe 3 made of round steel pipe. The excavation blades 32 serve as support blades for supporting the shaft steel pipe 31 in the ground after the penetration of the steel pipe pile 3.

[0023] As shown in FIGS. 2 and 3, the insertion rotation portion 11 of the placer 1 can be inserted into and removed from the shaft steel pipe 31, and is rotated about the axis of the shaft steel pipe 31 in the shaft steel pipe 31 in the inserted state. This rotation is applied by the rotation lifting portion 21 of the placer 2. The insertion rotation portion 11 is made of a relatively thick round steel pipe material having an outer diameter that is, for example, about 5 mm to 40 mm smaller than the inner diameter of the shaft steel pipe 31. In this embodiment, the rear end side of the insertion rotation portion 11 has a length protruding from the shaft steel pipe 31, and the rear end side is held by the rotation lifting portion 21. Note that the insertion rotation portion 11 is not limited to round steel pipe materials and may be made of square steel pipe materials or bar steel materials.

[0024] The rotation transmission unit 12 is located at the tip of the insertion-rotating unit 11 and fits into the center of the drilling blade 32, transmitting the rotation of the insertion-rotating unit 11 to the drilling blade 32. The rotation transmission unit 12 only needs to have a structure that can transmit rotational torque to the drilling blade 32.

[0025] In this embodiment, the rotation transmission unit 12 fits into a circular concave receiving fitting portion 32a formed in the center of the drilling blade 32. The rotation transmission unit 12 also includes a pair of hook portions 12a that each fit under a pair of opposing engaging portions 32b that protrude toward the center from the inner circumferential surface of the receiving fitting portion 32a and hook onto the drilling blade 32. When inserting the insertion rotation unit 11 into the shaft steel pipe 31, the driving tool 1 is lowered while avoiding contact between the pair of hook portions 12a and the pair of engaging portions 32b, and after the rotation transmission unit 12 enters the receiving fitting portion 32a, the driving tool 1 is rotated by approximately 90 degrees, allowing the pair of hook portions 12a to fit under the pair of engaging portions 32b.

[0026] Furthermore, in the steel pipe pile with drilling wings 3, the drilling wings 32 are rotatably fitted to the tip side of the shaft steel pipe 31 without being fixed to the shaft steel pipe 31. If the shaft steel pipe 31 and the drilling wings 32 were fixed to each other, the thrust force in the soil caused by the rotation of the drilling wings 32 would allow the shaft steel pipe 31 to be driven into the ground 4 together with the drilling wings 32. However, as described above, if they are rotatable, the thrust force in the soil caused by the rotation of the drilling wings 32 would not allow the shaft steel pipe 31 to be driven into the ground 4 together with the drilling wings 32. For this reason, in addition to the insertion and rotation part 11 and the rotation transmission part 12, the driving tool 1 is equipped with a movable force applying part 5 that applies the moving force of the insertion and rotation part 11 in the direction of penetration to the rear end side of the shaft steel pipe 31. A specific example of the movable force applying part 5 will be described later. The appearance of this steel pipe pile 3 may be the same as that of existing ones.

[0027] Furthermore, in the steel pipe pile 3 with drilling blades, a fitting upright portion 32d is formed on the outer peripheral wall portion 32c outside the central part of the drilling blade 32, rising inward from the outer peripheral wall portion 32c. This fitting upright portion 32d fits into the shaft steel pipe 31, thereby restricting the lateral movement of the shaft steel pipe 31 (in a direction intersecting the penetration direction of the shaft steel pipe 31) when the drilling blade 32 rotates. Thus, it is possible to prevent the shaft steel pipe 31 from coming off laterally from the drilling blade 32.

[0028] In the penetration of the steel pipe pile 3 into the ground 4, as shown in Figure 1, the following steps are taken: inserting the insertion rotating part 11 of the driving tool 1 into the shaft steel pipe 31 of the steel pipe pile 3 with excavation wings, and fitting the rotation transmission part 12 into the center (receiving fitting part 32a) of the excavation wings 32; attaching the movable force applying part 5 to the insertion rotating part 11 and attaching the rear end of the insertion rotating part 11 to the rotating lifting part 21 of the driving machine 2; lowering the rotating lifting part 21 to rotate the excavation wings 32 and applying a moving force in the direction of penetration to the rear end of the shaft steel pipe 31 by the movable force applying part 5 to penetrate the steel pipe pile 3 into the ground 4; and raising the rotating lifting part 21 to remove the driving tool 1 from the shaft steel pipe 31. Furthermore, if it becomes necessary to remove the steel pipe pile 3 with excavation wings from the ground 4, the steel pipe pile 3 with excavation wings can be removed from the ground 4 by rotating the insertion and rotation part 11 in the opposite direction to that used for penetration.

[0029] In this manner, the insertable rotating part 11 is inserted into the shaft steel pipe 31, and the steel pipe pile 3 with excavating wings is rotated to excavate the ground 4. Therefore, the ground 4 around the shaft steel pipe 31 is not significantly disturbed, nor is soil removed. Consequently, there is no need to compact the disturbed ground 4 or fill in the removed soil. Furthermore, since it is the steel pipe pile 3 that is in contact with the ground 4, the driving tool 1 does not wear down with each excavation.

[0030] Furthermore, the rotational force from the rotating lifting section 21 of the driving machine 2 is not transmitted from the shaft steel pipe 31 to the drilling blade 32, but rather from the insertion rotating section 11 of the driving tool 1 to the drilling blade 32. Moreover, the drilling blade 32 is rotatably fitted to the shaft steel pipe 31 without being fixed, and the shaft steel pipe 31 is not forcibly rotated by the rotation of the drilling blade 32 during drilling, so torsional stress is less likely to occur on the shaft steel pipe 31. For this reason, it becomes easy to reduce the size of the shaft steel pipe 31 (reduce the diameter and reduce the thickness) to suppress ground improvement costs. In addition, even if the drilling blade 32 is not fixed to the shaft steel pipe 31, the moving force applying section 5 provides the moving force of the insertion rotating section 11 in the direction of penetration to the rear end side of the shaft steel pipe 31, so that the shaft steel pipe 31 can be driven into the ground 4.

[0031] Furthermore, if the rotation transmission unit 12 of the driving tool 1 is equipped with a hook portion 12a, the steel pipe pile 3 with excavation wings can be hooked onto the driving tool 1 and supported, making it easier to move the steel pipe pile 3 to the excavation site. Of course, the rotation transmission unit 12 can also be constructed without the hook portion 12a.

[0032] Furthermore, the insertable rotating part 11 has a projection 11a that protrudes from the shaft steel pipe 31 at its rear end, and the movable force applying part 5 is attached to the outer circumference of this projection 11a. In addition, for example, a hexagonal prism protrudes from the center of the rear end of the insertable rotating part 11, and a hexagonal hole into which this hexagonal prism fits is formed in the rotating lifting part 21, and the rotational force of the rotating lifting part 21 is transmitted to the insertable rotating part 11 by this joint structure.

[0033] The movable force-applying part 5 consists of an insertion member 5b (such as a bolt) that is inserted (screwed) into a hole 5a (for example, a screw hole) formed on the outer circumferential surface of the protruding part 11a, protrudes from the outer circumferential surface, and contacts the rear end of the shaft steel pipe 31. The insertion member 5b is not limited to a bolt; it may also be a pin member, in which case the hole 5a is a pin insertion hole.

[0034] The example of the movable force-applying unit 5 has the disadvantage that its mounting position is limited to a fixed position. However, if multiple holes 5a are provided at different heights on the rear end side of the insertion and rotating unit 11, the mounting height position of the movable force-applying unit 5 can be changed according to the length of the shaft steel pipe 31.

[0035] Figure 4 shows a modified example of the movable force-applying part 5, which is a movable force-applying part 5A made of a flange-shaped member. This movable force-applying part 5A is locked into a circumferential recess 11b formed on the outer surface of the protruding part 11a, protruding from the outer surface and able to contact the rear end of the shaft steel pipe 31. In the illustrated example, the flange-shaped member has a separable split structure, and a bolt 5c inserted through an insertion hole at one end of one split part is screwed into a threaded hole 5d at the other end of the split part. The structure is not limited to this, and a structure in which one end of one split part and one end of the other split part are connected by a hinge is also possible.

[0036] In the example of the movable force-applying unit 5A, the circumferential recess 11b consists of a single recess, which has the disadvantage of limiting its mounting position to a fixed position. However, if, for example, the circumferential recess 11b consists of multiple circumferential recesses, the mounting height position of the movable force-applying unit 5A can be changed according to the length of the shaft steel pipe 31.

[0037] Figure 5(A) shows a modified example of the movable force-applying part 5, which is a movable force-applying part 5B made of an annular pressure-welded member. This movable force-applying part 5B is pressed against the outer surface of the protruding part 11a and protrudes, contacting the rear end of the shaft steel pipe 31. With the movable force-applying part 5B, it is easy to change its mounting position according to the length of the shaft steel pipe 31. In the illustrated example, the annular pressure-welded member has a separable split structure, and a bolt 5c inserted through the insertion hole at one end of the split part is screwed into the threaded hole 5d at the other end of the split part. The structure is not limited to this, however, the threaded hole 5d may be a bolt insertion hole, and a nut may be screwed onto the tip of the bolt 5c that passes through this bolt insertion hole. Alternatively, instead of a separable split structure, one end of one split part and one end of the other split part may be connected by a hinge. With the movable force-applying part 5B, it is easy to change its mounting position according to the length of the shaft steel pipe 31.

[0038] Furthermore, as shown in Figure 5(B), the movable force-applying part 5B may consist of a rectangular annular pressure-welding member with a circular opening that is fitted onto the protruding part 11a from above. A screw hole 5d leading to the circular opening is formed on the side surface of this annular pressure-welding member with a circular opening, and a bolt 5c is screwed into this screw hole 5d. When the tip of this bolt 5c is pressed against the protruding part 11a, the circumferential surface of the circular opening is pressed against the protruding part 11a on the opposite side of the position of the bolt 5c. The number of screw holes 5d and bolts 5c is not limited to one, and they may be formed on each side surface of the annular pressure-welding member. Also, the outer shape of the annular pressure-welding member is not limited to a rectangular shape, but may be circular.

[0039] Figure 6 also shows a movable force-applying section 5B consisting of an annular pressure-welding member. In this movable force-applying section 5B, the annular pressure-welding member consists of an annular chain-like member, and a screw hole 5d is formed in a block-like member that forms part of this annular chain-like member, and a bolt 5c is screwed into this screw hole 5d. When the tip of this bolt 5c is pressed against the protruding portion 11a, the chain-like member is also pressed against the protruding portion 11a on the opposite side of the position of the bolt 5c.

[0040] In these movable force-applying sections 5B, the annular pressure-contacting member is pressed against the outer circumferential surface of the protrusion 11a to fix its position. Therefore, it is preferable that the outer circumferential surface of the protrusion 11a be processed to improve friction, such as knurling, rather than being smooth. Furthermore, the portion of the movable force-applying section 5B that presses against the outer circumferential surface of the protrusion 11a may also be processed to improve friction.

[0041] Furthermore, in the above example, the movable force-applying parts 5, 5A, and 5B were attached to the cylindrical projection 11a, but the invention is not limited to this, and they may be attached to a square or hexagonal projection 11a. Also, in the above example, the movable force-applying parts 5, etc. were attached to the rear end side of the insertion-rotating part 11, but the invention is not limited to this, and instead of providing the movable force-applying parts to the insertion-rotating part 11, they may be provided to the rotating lifting part 21 that provides the insertion-rotating part 11 with a moving force for penetration, and the moving force in the direction of penetration may be provided to the rear end side of the shaft steel pipe 31.

[0042] Figure 7 shows a modified example of the steel pipe pile 3 with excavation wings. In this modified example, the excavation wings 32 of the steel pipe pile 3 have an outer rising portion 32e that rises outside the outer peripheral wall portion 32c, and the shaft steel pipe 31 is fitted between the outer rising portion 32e and the fitting rising portion 32d. This more reliably prevents the shaft steel pipe 31 from coming off laterally.

[0043] Figure 8 illustrates the procedure for preparing to drive a steel pipe pile 3 with drilling wings. In this example, with the steel pipe pile 3 lying on its side, the insertion and rotating part 11 of the driving tool 1 is inserted into the shaft steel pipe 31. Then, the driving tool 1 and the steel pipe pile 3 are raised, and the driving tool 1 and the steel pipe pile 3 are made vertical. The connecting projection (for example, a hexagonal prism) protruding from the center of the rear end of the insertion and rotating part 11 (a position above the movable force application part 5) is fitted into the mounting recess (for example, a hexagonal hole) of the rotating lifting part 21, thereby preparing the steel pipe pile 3 for driving.

[0044] Figure 9 shows another example of the procedure for preparing to drive a steel pipe pile 3 with drilling wings. In this example as well, the insertion and rotation part 11 of the driving tool 1 can be inserted into the shaft steel pipe 31 with the steel pipe pile 3 lying on its side. The driving tool 1 has a connecting projection that protrudes from the center of the rear end of the insertion and rotation part 11 (above the movable force application part 5) and is rotatable by a joint 14 such as a hinge or universal joint. Therefore, even when the steel pipe pile 3 with drilling wings is tilted upright with the driving tool 1 inserted, only the connecting projection can be raised vertically. The lowered rotating lifting part 21 can be fitted into this vertically rising connecting projection, allowing the driving tool 1 and the steel pipe pile 3 to be raised vertically. Furthermore, with the steel pipe pile 3 with excavation wings laid on its side and the insertion and rotating part 11 of the driving tool 1 inserted into the shaft steel pipe 31, it is also possible to raise only the connecting projection vertically and fit the rotating and lifting part 21 into this connecting projection.

[0045] Although embodiments of this invention have been described above with reference to the drawings, this invention is not limited to the illustrated embodiments. Various modifications and variations can be made to the illustrated embodiments within the same scope as this invention, or within the equivalent scope. [Explanation of Symbols]

[0046] 1: Driving tool 2: Concrete pouring machine 3: Steel pipe pile with excavation wings 4: Ground 5: Mobility Granting Unit 5A: Mobility imparting section 5B: Mobility Granting Unit 5a: Hole 5b: Insertion part 5c: Bolt 5d: Screw hole 11: Insertion and rotation part 11a:Protrusion 11b: Circumferential recess 12: Rotation transmission section 12a: Hook part 14: Joint 21: Rotating and lifting section 31: Shaft steel pipe 32: Excavation blade 32a: Receiving and fitting part 32b: Engagement part 32c: Outer wall 32d: Upper part of the fitting 32e: Outside standing part

Claims

1. A driving tool for a steel pipe pile, wherein the drilling blades are fitted to the tip of the shaft steel pipe but are not fixed to the shaft steel pipe, and the tool is characterized by comprising: an insertion and rotation part that can be inserted into and removed from the shaft steel pipe and rotates inside the shaft steel pipe when inserted; a rotation transmission part provided on the tip side of the insertion and rotation part, which fits into the center of the drilling blades and transmits the rotation of the insertion and rotation part to the drilling blades; and a movement force applying part that applies a movement force in the direction of penetration to the rear end side of the shaft steel pipe.

2. A steel pipe pile driving tool according to claim 1, characterized in that the rear end of the insertion and rotating part has a protruding part that extends out from the shaft steel pipe, and the movable force applying part is attached to the outer circumference of this protruding part.

3. The steel pipe pile driving tool according to claim 2, wherein the movable force applying part is an insertion member that is inserted into a hole formed on the outer circumferential surface of the protruding part, protrudes from the outer circumferential surface, and contacts the rear end of the shaft steel pipe.

4. A steel pipe pile driving tool according to claim 2, wherein the movable force applying part is a flange-shaped member that is engaged with a circumferential recess formed on the outer surface of the protruding part, protrudes from the outer surface, and contacts the rear end of the shaft steel pipe.

5. A steel pipe pile driving tool according to claim 2, characterized in that the movable force applying part is an annular pressure contact member that is pressed against the outer circumferential surface of the protruding part, protrudes from the outer circumferential surface, and contacts the rear end of the shaft steel pipe.

6. A steel pipe pile with drilling wings, wherein drilling wings are fitted to the tip of the shaft steel pipe without being fixed to the shaft steel pipe, and the drilling wings are characterized in that the center of the drilling wings has a receiving fitting portion into which the rotation transmission portion of the steel pipe pile driving tool described in any one of claims 1 to 5 is fitted.

7. The steel pipe pile with drilling blades according to claim 6, wherein a fitting rising portion is formed on the outer peripheral wall portion outside the central part of the drilling blade, rising inward from the outer peripheral wall portion, the fitting rising portion fits into the shaft steel pipe, and the lateral movement of the shaft steel pipe when the drilling blade rotates is restricted by the fitting rising portion.

8. The steel pipe pile with drilling wings according to claim 7, characterized in that an outer rising portion is formed that rises outside the outer peripheral wall portion, and the shaft portion steel pipe is fitted between the outer rising portion and the fitting rising portion.

9. A method for driving a steel pipe pile, comprising the steps of: inserting the insertion rotating part of the steel pipe pile driving tool described in any one of claims 1 to 5 into the shaft steel pipe of the steel pipe pile with drilling wings, and fitting the rotation transmission part to the center of the drilling wings; attaching the rear end of the insertion rotating part to the rotating lifting part of the driving machine; lowering the rotating lifting part to rotate the drilling wings and applying a moving force in the direction of penetration to the rear end of the shaft steel pipe using the moving force applying part, thereby driving the steel pipe pile with drilling wings into the ground; and removing the driving tool from the shaft steel pipe.

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