JP2022190512A - Rotary penetration steel pipe pile with tip blade - Google Patents

Abstract

To provide a rotary penetration steel pipe pile with a tip blade which suppresses the influence of reaction acting on a wing part during rotary penetration, and prevents generation of damage during the rotary penetration.SOLUTION: A rotary penetration steel pipe pile 10 with a tip blade is composed of a cast member 20 welded and fixed to a tip 12 of a steel pipe body 11, wherein the cast member 20 has a cylinder part 21 having a diameter larger than the diameter of the steel pipe body 11 and a connection part 30 connected to the tip 12 of the steel pipe body 11 formed integrally with each other, the diameter of the connection part 30 is expanded downward from the diameter of the steel pipe body 11 to the diameter of the cylinder part 21, and the connection part 30 has a wing part 40 having a diameter 1.5 to 6 times the diameter of the cylinder part 21 in the vicinity of the tip of the cast member 20.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a rotary penetration steel pipe pile with a tip wing having a wing for rotary excavation at the tip.

For example, steel pipe piles used for foundation work of buildings have disk-shaped blades for rotary excavation on the tip side of the steel pipe body consisting of a tubular body, and are also called rotary penetrating steel pipe piles with tip blades. be done. A large number of these steel pipe piles are driven into the ground by a construction device and penetrated by rotation to support the foundation of a building. At that time, the larger the diameter and area of the wings, the greater the load that can be supported. Therefore, a steel pipe pile is known in which a cylindrical tip member with a diameter larger than the diameter of the steel pipe body is welded and attached to the tip of the steel pipe body, and a wing portion is provided on the outer periphery of the tip member to increase the diameter and area of the wing portion. (See Patent Document 1, for example).

In a steel pipe pile, a reaction force from the ground acts on the wing portion during rotary penetration, and a load is applied to the welded portion between the steel pipe body and the tip member and the vicinity thereof. However, when trying to increase the diameter and area of the wing to support a larger load, the reaction force acting on the wing also increases in proportion to the size of the diameter and area of the wing. As a result, the load on the welded portion of the tip member also increases. As a result, the welded portion of the tip member may not withstand the load and may be damaged.

JP 2016-173028 A

The present invention has been made in view of the above-mentioned points, and suppresses the influence of the reaction force acting on the wing portion during rotary penetration, making it difficult to cause damage during rotary penetration. It provides

That is, the invention of claim 1 is a rotary penetration steel pipe pile with a tip wing made of a cast member welded and fixed to the tip of a steel pipe body, wherein the cast member has a cylindrical portion having a diameter larger than the diameter of the steel pipe body. A connection portion connected to the tip of the steel pipe body is integrally formed, and the connection portion expands downward in diameter from the diameter of the steel pipe body to the diameter of the cylindrical portion, and the tip of the cast member. It relates to a rotary penetrating steel pipe pile with a tip wing, characterized by comprising a wing portion having a diameter 1.5 to 6 times as large as the diameter of the cylindrical portion in the vicinity.

According to a second aspect of the invention, the cast member has two inclined notch grooves that are symmetrically inclined with respect to an imaginary plane containing the central axis in the vicinity of the tip of the tubular portion, and from the tip opening of the tubular portion. An excavating member made of a flat steel plate whose tip protrudes and whose plate thickness surface is welded and fixed at a mounting position near the tip where the pipe inner peripheral surface of the cylindrical portion and the imaginary plane intersect, and the wing portion is a flat semicircle. It consists of two shaped semi-disk-shaped wings, said two semi-disk-shaped wings being crosswise inserted into the tubular body of said cast member through two oblique notch grooves of said cast member. 2. The rotating penetration steel pipe pile with a tip wing according to claim 1, wherein the contact portion between the semi-disk-shaped wing portion and the excavating member and the insertion portion of the notch groove are fixed by welding.

The invention of claim 3 relates to the rotary penetrating steel pipe pile with tip wings according to claim 2, wherein the excavation member is made of a plate member having the same width as that of the mounting position and has a pointed end.

The invention of claim 4 relates to the rotary penetrating steel pipe pile with a tip wing according to claim 2 or 3, wherein no inclined notch groove is formed at the mounting position.

The invention of claim 5 is a rotary penetration steel pipe pile with a tip wing made of a cast member welded and fixed to the tip of a steel pipe body, wherein the cast member comprises a cylindrical portion having a diameter larger than that of the steel pipe body and the steel pipe. A connecting portion connected to the tip of the main body and a wing portion having a diameter 1.5 to 6 times as large as the diameter of the cylindrical portion are integrally formed near the tip of the tubular portion, and the connecting portion has a diameter of the steel pipe main body. It relates to a rotating penetration steel pipe pile with a tip wing, characterized in that the diameter is expanded downward from to the diameter of the cylindrical portion.

According to a sixth aspect of the present invention, the wing portions are composed of two semi-disk-shaped wing portions formed in a planar semicircular shape, and the two semi-disk-shaped wing portions are formed in a cross shape near the tip of the cylindrical portion. It relates to the rotating penetration steel pipe pile with a tip wing according to claim 5.

The invention according to claim 7 is characterized in that the angle of intersection between the semi-disc-shaped wing portion and a plane perpendicular to the central axis of the tubular body is 5 degrees to 20 degrees. It relates to rotating penetrating steel pipe piles with tip wings.

The invention of claim 8 is the rotary penetration steel pipe with tip wings according to any one of claims 1 to 7, wherein the wing has a diameter that is 2.5 to 5.5 times the diameter of the cylinder. related to piles.

The invention of claim 9 relates to the rotating penetration steel pipe pile with a tip wing according to any one of claims 1 to 8, wherein the connection portion is formed of an outwardly convex curved surface.

A rotary penetration steel pipe pile with tip wings according to the invention of claim 1 is a rotary penetration steel pipe pile with tip wings made of a cast member welded and fixed to the tip of a steel pipe body, wherein the cast member is larger than the diameter of the steel pipe body. A cylindrical portion having a large diameter and a connecting portion connected to the tip of the steel pipe body are integrally formed, and the connecting portion expands downward from the diameter of the steel pipe body to the diameter of the cylindrical portion. Since a wing portion having a diameter of 1.5 to 6 times the diameter of the cylindrical portion is provided near the tip of the cast member, the load due to the reaction force acting on the wing portion during rotational penetration can be reduced. As a result, it is less likely to be damaged during rotary penetration, and it can withstand the reaction force from the ground while supporting a large load.

The invention of claim 2 is based on claim 1, wherein the cast member has two inclined notch grooves inclined symmetrically with respect to an imaginary plane containing the central axis in the vicinity of the tip of the cylindrical portion, and an excavating member made of a flat steel plate whose thickness surface is welded and fixed at a mounting position near the tip where the tip portion protrudes from the tip opening of the tubular portion and the imaginary plane intersects the pipe inner peripheral surface of the cylindrical portion; The two semi-disk-shaped wing portions are formed in a planar semicircular shape, and the two semi-disk-shaped wing portions extend into the tubular body of the cast member through two inclined notch grooves of the cast member. and the contact portion between the semi-disk-shaped wing portion and the excavating member and the insertion portion of the notch groove are welded and fixed, so that the fixing strength between the cast member and the wing portion is It can be greatly improved, and each wing with a large diameter can withstand the reaction force that acts at the time of rotation penetration and the case where rotation penetration is stopped and reverse rotation, etc., and there is a risk that the wing will fall off from the cast member. It becomes possible to reliably and easily manufacture a steel pipe pile without any defects.

According to the invention of claim 3, in claim 2, the excavation member is made of a plate-like member having the same width as that of the mounting position and has a pointed end. , which can excavate the ground efficiently during rotary penetration.

According to the invention of claim 4, in claim 2 or 3, since no inclined notch groove is formed at the mounting position, positioning of the excavating member with respect to the mounting position is facilitated.

A rotary penetration steel pipe pile with tip wings according to the invention of claim 5 is a rotary penetration steel pipe pile with tip wings made of a cast member welded and fixed to the tip of a steel pipe body, wherein the cast member is larger than the diameter of the steel pipe body. A cylindrical portion having a large diameter, a connection portion connected to the tip of the steel pipe body, and a wing portion having a diameter 1.5 to 6 times the diameter of the cylindrical portion near the tip are integrally formed, Since the diameter of the connection portion is expanded downward from the diameter of the steel pipe body to the diameter of the cylindrical portion, it is possible to reduce the load due to the reaction force acting on the wing portion during rotary penetration. It is less likely to break, and can withstand the reaction force from the ground while supporting a large load.

According to a sixth aspect of the invention, in the fifth aspect, the wing portion is composed of two semi-disk-shaped wing portions formed in a planar semicircular shape, and the two semi-disk-shaped wing portions are located near the tip of the cylindrical portion. Since it is formed in a cross shape, it is easy to form by casting.

The invention according to claim 7 is based on claims 2 to 4 or 6, in which the angle of intersection between the semi-disk-shaped wing portion and a plane perpendicular to the central axis of the tubular body is 5 degrees to 20 degrees. In addition to efficiently excavating the ground, the load can be properly supported.

According to the invention of claim 8, in the invention of claims 1 to 7, the wing portion has a diameter 2.5 to 5.5 times as large as the diameter of the cylindrical portion. , can withstand the reaction force from the ground during rotary penetration.

According to the ninth aspect of the invention, in the first aspect to the eighth aspect, the connecting portion is formed of an outwardly convex curved surface.

1 is an exploded perspective view of a rotary penetrating steel pipe pile with tip wings according to one embodiment of the present invention. FIG. FIG. 2 is a side view of the steel pipe pile of FIG. 1; FIG. 2 is a front view of the steel pipe pile of FIG. 1; FIG. 2 is a cross-sectional view of a main part of the steel pipe pile of FIG. 1; FIG. 4 is a cross-sectional view of a main part showing a welded state between a connecting portion of a cast member and a steel pipe body; It is an exploded perspective view of the rotation penetrating steel pipe pile with a tip wing concerning other embodiments. It is a principal part sectional view of the conventional steel pipe pile.

The steel pipe pile 10 according to one embodiment of the present invention shown in FIGS. It is a member for supporting the foundation, and is called a rotary penetrating steel pipe pile with a tip wing. This steel pipe pile 10 has a steel pipe main body 11 , a cast member 20 and wings 40 .

The steel pipe main body 11 consists of a tubular body that is rotated and penetrated into the ground. Since the steel pipe body 11 is a portion that does not affect the excavated area of the ground, it is formed to have a diameter smaller than that of the cast member 20, which will be described later, so that weight reduction and cost reduction can be achieved. In FIG. 1 , reference numeral 12 is the tip of the steel pipe body 11 .

The cast member 20 is a member that is welded to the front end 12 of the steel pipe body 11, and is formed by integrally forming the cylindrical portion 21 and the connecting portion 30 by casting. The tubular portion 21 is a cylindrical portion having a diameter larger than that of the steel pipe body 11 . As shown in FIG. 2, the cast member 20 of the embodiment has two inclined notch grooves 22 and 23 that are symmetrically inclined with respect to an imaginary plane D that includes the central axis C near the tip of the cylindrical portion 21. , having an excavating member 25 therein. The central axis C of the cast member 20 corresponds to the center of rotation of the steel pipe pile 10 during rotational penetration.

The inclined notch grooves 22 and 23 are portions to which semi-disk-shaped wings 50 and 60, which will be described later, are attached. As shown in FIG. 3, the oblique notch grooves 22 and 23 define an intersection angle (.theta.) between the semi-disk-shaped wing portion 50 (60) and a plane P perpendicular to the central axis C of the tubular body. The inclined notch grooves 22 and 23 are formed by a known cutting device or the like.

The excavating member 25 is made of a flat steel plate for ground excavation, and as shown in FIG. 26 is fixed by welding. As shown in FIGS. 2 and 3, the excavating member 25 is arranged so that the tip protrudes from the tip opening 21a of the cylindrical portion 21. As shown in FIGS.

4, the excavating member 25 is made of a plate member having the same width as the mounting positions F, F. As shown in FIG. That is, the excavating member 25 is formed to have substantially the same width as the diameter of the inner periphery of the tubular portion 21 . Therefore, the plate-like excavating member 25 is appropriately arranged in the center of the tubular body of the tubular portion 21 along the imaginary plane D. As shown in FIG. Although the thickness of the excavating member 25 is not particularly limited, it is, for example, about 9 mm from the viewpoint of strength and the like. 3, the excavating member 25 has a tip portion 27 having an acute-angled tip. This pointed end 27 is located on the central axis C. As shown in FIG. Therefore, the ground can be excavated efficiently during rotary penetration.

As shown in FIG. 2, the inclined notch grooves 22 and 23 are not formed at the mounting position F of the excavating member 25 (near the tip portion of the tubular inner peripheral surface of the cast member 20 where the imaginary plane D intersects). is preferred. In particular, the range (width) where the inclined notch grooves 22 and 23 are not formed at the mounting positions F and F is more preferably formed substantially equal to the thickness of the excavating member 25 . This makes it easy to position the excavating member 25 with respect to the mounting positions F, F using the respective ends of the inclined notch grooves 22, 23 as a guide.

The connection portion 30 is a portion that is welded to the front end 12 of the steel pipe body 11 , and is expanded downward from the diameter of the steel pipe body 11 to the diameter of the cylinder portion 21 . As shown in FIG. 5 , the connecting portion 30 has an upper portion (steel pipe body 11 side) formed as a horizontal portion 31 and a lower portion (cylindrical portion 21 side) integrally connected to the cylindrical portion 21 . 2, 3, and 5, one or a plurality of stepped portions 33 are formed on the outer surface 32 along the entire circumference of the connecting portion 30, if necessary. In addition, in the embodiment, the outer surface 32 of the connecting portion 30 has a shape formed by a curved surface 32a that protrudes outward.

In the connection portion 30, as shown in FIG. 5(a), the tip 12a of the steel pipe body 11A having substantially the same diameter as the horizontal portion 31 is brought into contact with the horizontal portion 31 on the upper side, thereby connecting the horizontal portion 13 and the steel pipe body 11A. is welded to the tip 12a of the . Moreover, since the diameter of the outer surface 32 of the connecting portion 30 is enlarged, it is possible to weld the steel pipe main body 11B having a diameter larger than that of the horizontal portion 31, as shown in FIG. 5(b). That is, since the horizontal portion 31 of the connection portion 30 has a smaller diameter than the steel pipe body 11B, the horizontal portion 31 enters the steel pipe body 11B, and the tip 12b of the steel pipe body 11B contacts the outer surface 32 of the connection portion 30. be. Then, the outer surface 32 of the connecting portion 30 and the tip 12b of the steel pipe body 11B can be welded together to fix them together. At this time, by placing the front end 12b of the steel pipe body 11B on the stepped portion 33 formed on the outer surface 32 of the connecting portion 30, the large-diameter steel pipe body 11B can be stably welded and fixed.

Further, in the connecting portion 30 , the horizontal portion 31 is positioned substantially at the center, and the outer surface 32 (curved surface 32 a ) is evenly expanded downward from the horizontal portion 31 . Therefore, when welding the steel pipe body 11 (11A, 11B) to the cast member 20, regardless of whether the steel pipe body 11A has substantially the same diameter as the horizontal portion 31 or the steel pipe body 11B has a diameter larger than that of the horizontal portion 31, can be easily positioned in the center of the

The wing portion 40 is a member that excavates the ground outside the cast member 20 during rotary penetration, and is welded near the tip of the cylindrical portion 21 of the cast member 20 . The larger the diameter and area of the wing portion 40, the greater the load it can support, but the greater the influence of the reaction force from the ground during rotary penetration. Therefore, the wing portion 40 has a diameter of 1.5 to 6 times the diameter of the cylindrical portion 21 of the cast member 20 in order to be able to withstand the reaction force from the ground while being able to support a larger load. , more preferably 2.5 to 5.5 times the diameter. If the diameter of the wing portion 40 is too small, it may not be able to support the load sufficiently.

The shape of the wing portion 40 is not particularly limited as long as it is protruded in a wing shape from the outer periphery of the cylindrical portion 21 and can excavate the ground by rotating, such as being formed in a spiral shape or a disk shape on the outer periphery of the cylindrical portion 21. . As shown in FIGS. 1 and 4, the wing portion of the embodiment consists of two semi-disk-like wing portions 50 and 60 formed in a plane semicircular shape. The semi-disk-shaped wing portion 50 (60) has a planar semicircular wing main body 51 (61) and a blade portion 55 (65). The blade portion 55 (65) is a portion for excavating the ground outside the cast member 20, and is formed on one end side of the chord portion 52 (62) of the blade main body 51 (61). The blade angle of the blade portion 55 (65) is, for example, 45 degrees.

As shown in FIGS. 2 to 4, the two semi-disk-shaped wings 50 and 60 are inserted crosswise into the tubular body through the two inclined notch grooves 22 and 23, and the semi-disk-shaped wings The contact portions 28 and 29 between the portions 50 and 60 and the excavating member 25 and the insertion portions 22a and 23a of the notch grooves 22 and 23 are fixed by welding. Each semi-disk shaped wing 50 , 60 is symmetrically arranged by a digging member 25 fixed at a mounting position F, F corresponding to the center of the cast member 20 . As shown in FIG. 3, the two semi-disk-shaped wing portions 50 and 60 are arranged so that the blade portions 55 and 65 are on the lower side so that they are crossed when viewed from the front. By placing the blades 55 and 65 on the lower side, it becomes easier to excavate the ground.

The semi-disk-shaped wing portions 50 and 60 are inserted into the tubular body from the notch grooves 22 and 23 of the cast member 20 and welded. At this time, the semi-disk-shaped wings 50 and 60 are welded to the notch grooves 22 and 23, and are also welded to the excavating member 25 at the contact portions 28 and 29 while being inserted into the casting member 20. will be Therefore, compared to simply welding the wings 50 and 60 to the outer periphery of the cast member 20, the fixing strength of the wings 50 and 60 to the cast member 20 is significantly improved.

Semi-disc shaped wings 50, 60, as shown in FIG. It is preferable that the intersection angle (θ) with the plane P perpendicular to the central axis C is 5 degrees to 20 degrees. If the crossing angle (θ) of the semi-disk-shaped wing portions 50 and 60 is too small, the inclination of the two wing portions 50 and 60 is small and the state is close to horizontal, and the excavation efficiency of the ground outside the cast member 20 is increased. may get worse. If the crossing angle (θ) of the semi-disk-shaped wing portions 50, 60 is too large, the surfaces of the two wing portions 50, 60 become steep and the area with respect to the horizontal direction becomes small, so that the load can be sufficiently supported. There is a risk that you will not be able to

Next, a working process using the steel pipe pile 10 will be described. First, the steel pipe pile 10 is erected from the ground by a construction device (not shown) installed on the ground, and the steel pipe pile 10 is pressed downward while being rotated. At that time, since the excavating member 25 protrudes from the tip opening 21 a of the cylindrical portion 21 of the cast member 20 , the excavating of the ground is started by the excavating member 25 . The earth and sand below the cast member 20 excavated by the excavating member 25 are pushed away by the excavating member 25 and the two semi-disk-shaped wing portions 50 and 60 toward the outer peripheral side. At the same time, the ground outside the cast member 20 is excavated by the two semi-disk-shaped wings 50 and 60, and the steel pipe pile 10 is rotated and penetrated into the ground.

When the steel pipe pile 10 rotates and penetrates, an upward reaction force in the vertical direction and in a direction opposite to the rotation acts on the wing portions 50 and 60 from the ground. Due to the reaction force on the wing portions 50 and 60, a load is applied to the welded portion between the steel pipe body 11 and the cast member 20 and the portions in the vicinity thereof.

Here, in the conventional steel pipe pile 100 shown in FIG. and the wing portion 140 are welded to the outer periphery thereof, and the steel pipe main body 111 is welded to the top plate member 122 . In particular, since the steel pipe body 111 is welded substantially perpendicularly to the top plate member 122, when a reaction force acts on the wing portion 140 in the direction opposite to the axial rotation of the steel pipe pile 100, the tip body 121 and the top plate member 122 A torsional load is applied to the surface. At that time, since the strength of the vicinity of the welded portion is inferior to that of the welded portion, the vicinity of the welded portion between the steel pipe body 111 and the top plate member 122 and the vicinity of the welded portion between the tip body 121 and the top plate member 122 are damaged. can occur.

On the other hand, in the steel pipe pile 10 of the present invention, the connection portion 30 of the cast member 20 is expanded downward from the steel pipe main body 11 side to the cylindrical portion 21 side. Therefore, the outer surface 32 of the connection portion 30 near the welded portion of the cast member 20 with the steel pipe body 11 is inclined (non-perpendicular) to the steel pipe body 11 , and the reaction force on the wings 50 and 60 The torsional load generated in the vicinity of the welded portion of the cast member 20 with the steel pipe body 11 can be reduced. In particular, since the connecting portion 30 is the outwardly convex curved surface 32a, it is possible to more effectively reduce the load due to the reaction force. Therefore, it is possible to suppress the influence of the reaction force on the wing portions 50 and 60 at the time of rotary penetration, and damage is less likely to occur at the time of rotary penetration. Furthermore, since the cylindrical portion 21 and the connecting portion 30 are integrally formed by casting, the cast member 20 does not have a welded portion. No fear.

Further, in the steel pipe pile 10, the wings 50, 60 are welded and fixed to the cast member 20 and the excavation member 25 in a state of being inserted into the cast member 20, so that the wings 50, 60 are fixed to the cast member 20. Strength is greatly improved. Therefore, the diameter of each wing 50, 60 is increased to 1.5 to 6 times, preferably 2.5 to 5.5 times, the diameter of the cast member 20, so that the reaction force acting from the ground is progressive. Even if the wing portions 50 and 60 are relatively large, the fixing strength of the wing portions 50 and 60 to the cast member 20 is not insufficient, and the wing portions 50 and 60 do not drop off from the cast member 20 .

Further, each wing portion 50, 60 is fixed in a state in which it is inserted into the tubular body through the notch grooves 22, 23 of the cast member 20, so that each wing portion 50, 60 has an inside of the cast member 20. In addition, a vertical upward reaction force acts from the ground on the outer side. Therefore, the problem of partial deformation, such as deformation of only the outer peripheral side of the wing portions 50 and 60, is less likely to occur. As a result, the direction of travel of the steel pipe pile 10 is less likely to shift, and the occurrence of defects such as deformation of the cast member 20 due to the shift of the direction of travel and the like is suppressed.

Furthermore, when the load of a building or the like is applied to the steel pipe pile 10 that has been rotationally penetrated into the ground, each wing portion 50, 60 receives a vertical upward reaction force from the ground. A building or the like is supported on the ground through the cast member 20 . In the steel pipe pile 10, the cast member 20 and the wing portions 50 and 60 are less likely to be deformed, so that the weight that the steel pipe pile 10 can support does not decrease from the design value. In addition, it can withstand the case where the rotation penetration is stopped and the rotation is reversed.

FIG. 6 shows a rotary penetrating steel pipe pile 10A with tip wings according to another embodiment, in which a cast member 20A is formed by integrally forming a cylindrical portion 21, a connecting portion 30, and a wing portion 40A. In the following description, the same reference numerals denote the same configuration, and the description is omitted.

The wing portion 40A is formed integrally near the tip of the cylindrical portion 21 by casting, and is a portion that excavates the ground outside the cast member 20 during rotary penetration. Since the wing portion 40A is integrally formed with the cylindrical portion 21 by casting, the welding process of the wing portion can be omitted, and the steel pipe pile 10A can be efficiently formed.

The shape of the wing portion 40A is not particularly limited as long as it is protruded in a wing shape from the outer periphery of the cylindrical portion 21 and can excavate the ground by rotating, such as being formed in a spiral shape or a disk shape on the outer periphery of the cylindrical portion 21. . For example, the wing portion 40A is composed of two semi-disk-shaped wing portions 50A and 60A which are formed in a planar semicircular shape, and the two semi-disk-shaped wing portions 50A and 60A are formed in the vicinity of the tip of the cylindrical portion 21 in an intersecting manner. This is preferable because it is easy to form by casting.

Semi-disk-shaped wing portions 50A and 60A formed in a crossing shape on the cylindrical portion 21 are configured to have substantially the same external shape as the wing portions 50 and 60 of the steel pipe pile 10 shown in FIGS. 2 and 3 after welding. Therefore, the semi-disk-shaped wing portions 50A and 60A are integrally formed so as to have a diameter 1.5 to 6 times, more preferably 2.5 to 5.5 times the diameter of the cylindrical portion 21. As a result, like the wings 50 and 60, it is possible to withstand the reaction force from the ground while supporting a large load. In addition, the semi-disk-shaped wing portions 50A and 60A have an intersection angle (θ) with a plane P perpendicular to the central axis C of the tubular body of 5 degrees to 20 degrees, so that the steel pipe pile 10 shown in FIGS. , the ground outside the cast member 20 can be efficiently excavated and the load can be adequately supported.

INDUSTRIAL APPLICABILITY As illustrated and explained above, the rotary penetration steel pipe pile with tip wing of the present invention comprises a cast member welded and fixed to the tip of a steel pipe body. The connection part connected to the tip of the main body is integrally formed, and the diameter of the connection part is expanded downward from the diameter of the steel pipe body to the diameter of the cylindrical part, so the reaction acting on the blade part during rotary penetration The load due to force can be reduced, and damage is less likely to occur during rotation penetration. In addition, since the cast member has a wing portion having a diameter 1.5 to 6 times the diameter of the cylindrical portion near the tip, the steel pipe pile can withstand the reaction force from the ground while being able to support a large load. can be provided.

As described above, in the rotary penetration steel pipe pile with a tip wing of the present invention, the load due to the reaction force acting on the wing portion during rotary penetration can be reduced, and the occurrence of damage can be suppressed. Therefore, it is a promising substitute for conventional steel pipe piles.

Reference Signs List 10, 10A Steel pipe pile 11, 11A, 11B Steel pipe body 12, 12a, 12b Tip of steel pipe body 20, 20A Cast member 21 Tubular portion 21a Tip opening of tubular portion 22, 23 Inclined notch groove 22a, 23a Inclined notch Groove insertion portion 25 Excavating member 26 Plate thickness surface 27 Pointed end 28, 29 Contact portion 30 Connection portion 31 Horizontal portion 32 Outer surface of connection portion 32a Curved surface 33 Stepped portion 40, 40A Wing portion 50, 50A, 60, 60A Half Disk-shaped wing portions 51, 61 Blade main body 52, 62 Chord portions 55, 65 Blade portion C Central axis of casting member D Virtual plane F Mounting position of excavating member P Plane orthogonal to central axis of tubular body θ Crossing angle

Claims (9)

A rotary penetrating steel pipe pile with a tip wing made of a cast member welded and fixed to the tip of a steel pipe body,
The cast member is integrally formed with a cylindrical portion having a diameter larger than the diameter of the steel pipe body and a connection portion connected to the tip of the steel pipe body,
The connecting portion is expanded downward in diameter from the diameter of the steel pipe body to the diameter of the tubular portion,
A rotary penetration steel pipe pile with a tip wing, characterized by comprising a wing portion having a diameter 1.5 to 6 times as large as the diameter of the cylindrical portion near the tip of the cast member. The cast member has two inclined notch grooves that are symmetrically inclined with respect to a virtual plane containing the central axis near the tip of the tubular portion, and the tip protrudes from the tip opening of the tubular portion. An excavation member made of a flat steel plate whose plate thickness surface is welded and fixed at a mounting position near the tip where the inner peripheral surface of the pipe and the virtual plane intersect,
The wing portion is composed of two semi-disk-shaped wing portions formed in a planar semicircular shape, and the two semi-disk-shaped wing portions extend through two inclined notch grooves of the cast member. 2. A rotating body with tip wings according to claim 1, wherein said semi-disk-shaped wings are inserted crosswise into the body, and the abutting portions between said semi-disc-shaped wings and said excavating member and the insertion portions of said notched grooves are fixed by welding. Penetrating steel pipe piles. 3. The rotary penetration steel pipe pile with tip wings according to claim 2, wherein said excavation member is made of a plate-like member having the same width as said mounting position and has a pointed end. 4. The rotary penetration steel pipe pile with tip wings according to claim 2 or 3, wherein no inclined notch groove is formed at said mounting position. A rotary penetrating steel pipe pile with a tip wing made of a cast member welded and fixed to the tip of a steel pipe body,
The cast member comprises a cylindrical portion having a diameter larger than that of the steel pipe body, a connecting portion connected to the tip of the steel pipe body, and a diameter 1.5 to 6 times the diameter of the cylindrical portion near the tip of the cylindrical portion. The wing portion having is integrally formed,
A rotating penetration steel pipe pile with a tip wing, wherein the connecting portion is expanded downward in diameter from the diameter of the steel pipe body to the diameter of the cylindrical portion. 6. The wing portion according to claim 5, wherein the wing portion is composed of two semi-disk-shaped wing portions formed in a planar semicircular shape, and the two semi-disk-shaped wing portions are formed in a crossing manner near the tip of the cylindrical portion. Rotating penetrating steel pipe pile with tip wing. 7. The rotating penetration steel pipe pile with tip wings according to claim 2, wherein the angle of intersection between the semi-disk-shaped wing portion and a plane perpendicular to the central axis of the tubular body is 5 degrees to 20 degrees. . The rotary penetration steel pipe pile with tip wings according to any one of claims 1 to 7, wherein the wings have a diameter 2.5 to 5.5 times the diameter of the cylinder. The rotary penetration steel pipe pile with a tip wing according to any one of claims 1 to 8, wherein the connecting portion has an outwardly convex curved surface.

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