JP2018017097A - Concrete pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a concrete pile, the flexural capacity and shear capacity of which become greater than ever.SOLUTION: A concrete pile comprises a cylindrical pile body part 5 that contains concrete and that has a hollow part 11, and a spiral member 3a that is arranged in the hollow part 11 of the pile body part 5 and spirally extends around an axis line of the pile body part 5 along an inner peripheral surface 13 of the pile body part 5. The spiral member 3a is brought into elastic contact with the inner peripheral surface 13 of the pile body part 5 so as to urge it toward the radial outside of the pile body part 5.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to concrete piles.

  Ready-made concrete piles generally have a hollow cylindrical shape. Some concrete piles are called concrete piles with outer shell steel pipes (SC piles). SC piles contain concrete and have a cylindrical pile body part having a hollow part and an outer peripheral surface of the pile body part. It is comprised by the outer shell steel pipe to cover (for example, refer patent document 1).

Japanese Patent No. 5265447

In hollow cylindrical concrete piles, when bending moment or shearing force acts and deforms, the concrete peels off from the inner peripheral surface of the pile body, and the bending strength and shearing strength drop sharply. There is a problem that it is easy. This problem can occur not only with normal concrete piles but also with SC piles.
In view of the above circumstances, an object of at least one embodiment of the present invention is to provide a concrete pile having improved bending strength and shear strength compared to the conventional one.

(1) A concrete pile according to at least one embodiment of the present invention is:
A cylindrical pile body including concrete and having a hollow portion;
A spiral member disposed in a hollow portion of the pile body portion and extending spirally around an axis of the pile body portion along an inner peripheral surface of the pile body portion;
Is provided.

  According to the said structure (1), when the helical member is arrange | positioned in the hollow part of a pile main-body part, a bending moment and a shearing force act on a pile main-body part, and a pile main-body part deform | transforms, by a helical member, It is suppressed that a part of pile main-body part peels from the internal peripheral surface of a pile main-body part. As a result, according to the configuration (1), the bending strength and the shear strength can be improved as compared with the conventional case.

(2) In some embodiments, in the configuration (1),
The spiral member is in contact with the inner peripheral surface of the pile main body.

  According to the said structure (2), since the spiral member is contacting the inner peripheral surface of a pile main-body part, it is suppressed that a part of pile main-body part peels from the inner peripheral surface of a pile main-body part by a spiral member. Is done. As a result, according to the configuration (2), the bending strength and the shear strength can be improved as compared with the conventional case.

(3) In some embodiments, in the configuration (1) or (2),
An outer shell steel pipe covering the outer peripheral surface of the pile main body is further provided.

  The concrete pile of the said structure (3) is a concrete pile with an outer shell steel pipe provided with an outer shell steel pipe. The concrete pile with outer shell steel pipe has higher bending strength and shear strength than ordinary concrete pile by having the outer shell steel pipe, but the pile body portion is separated from the inner peripheral surface of the pile body portion by the spiral member. The bending strength and the shear strength can be improved as compared with the conventional art by suppressing the part from peeling off.

(4) In some embodiments, in any one of the configurations (1) to (3),
The spiral member is in elastic contact with the inner peripheral surface of the pile main body so as to urge toward the radially outer side of the pile main body.

  According to the said structure (4), the spiral member is elastically contacting the inner peripheral surface of a pile main-body part so that it may urge toward the radial direction outer side of a pile main-body part. For this reason, even when the pile body part is deformed, a gap is prevented from being generated between the inner peripheral surface of the pile body part and the spiral member, and the spiral member ensures that a part of the pile body part is peeled off. Can be suppressed. As a result, according to the configuration (4), the bending strength and the shear strength can be improved as compared with the conventional case.

(5) In some embodiments, in any one of the configurations (1) to (4),
The spiral member is made of metal.

  According to the said structure (5), since the spiral member is comprised with the metal, it can suppress that a part of pile main-body part peels with a simple structure.

(6) In some embodiments, in any one of the above configurations (1) to (5),
The spiral member is constituted by a hollow tube,
The tube is filled with concrete, mortar, grout, water, oil, metal wire, or fiber.

  According to the configuration (6), the spiral member is constituted by a hollow tube, and the tube is filled with concrete, mortar, grout, water, oil, metal wire, or fiber. By filling the spiral member with water or the like, it is possible to increase the rigidity of the spiral member, and it is possible to suppress a part of the pile main body from peeling off with a simple configuration.

(7) In some embodiments, in the above configurations (1) to (6),
A pitch determining member for determining a spiral pitch of the spiral member is further provided.

  According to the said structure (7), it can suppress that the pitch of the spiral of a spiral member becomes excessive with a pitch determination member, and suppresses that a part of pile main-body part peels off with a spiral member. Can do.

(8) In some embodiments, in the configuration (1),
A metal flaking suppression wall disposed between the spiral member and the inner peripheral surface of the pile body portion;
The peeling suppression wall is curved along the inner peripheral surface of the pile main body so as to contact the inner peripheral surface of the pile main body,
The spiral member is in contact with the inner peripheral surface of the peeling prevention wall.

  According to the said structure (8), the inner peripheral surface of a pile main-body part can be covered over a wider range with a peeling suppression wall, and it can suppress that a part of pile main-body part peels. Under the present circumstances, since it can suppress that a peeling suppression wall leaves | separates from the internal peripheral surface of a pile main-body part with a helical member, it can suppress reliably that a part of pile main-body part peels.

  According to at least one embodiment of the present invention, a concrete pile having improved bending strength and shear strength than before is provided.

It is a schematic longitudinal cross-sectional view of the concrete pile with an outer shell steel pipe concerning a 1st embodiment of the present invention. FIG. 2 is a schematic cross-sectional view taken along line II-II in FIG. 1. It is a perspective view which shows roughly the helical member applied to the concrete pile with an outer shell steel pipe of FIG. It is a perspective view which shows roughly the spiral member applicable to the concrete pile with an outer shell steel pipe concerning a 2nd embodiment of the present invention. It is sectional drawing which shows a pitch determination member roughly with the helical member of FIG. It is a perspective view which shows roughly the helical member applicable to the concrete pile with an outer shell steel pipe concerning 3rd Embodiment of this invention. FIG. 7 is a perspective view schematically showing the spiral member of FIG. 6 in a reduced diameter state. It is a schematic longitudinal cross-sectional view of the concrete pile with a shell steel pipe which concerns on 4th Embodiment of this invention. FIG. 9 is a schematic cross-sectional view taken along line IX-IX in FIG. 8. It is a perspective view which shows roughly the peeling suppression wall applied to the concrete pile with an outer shell steel pipe of FIG. It is a schematic longitudinal cross-sectional view of the prestressed concrete pile concerning 5th Embodiment of this invention.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples. Absent.
For example, expressions expressing relative or absolute arrangements such as “in a certain direction”, “along a certain direction”, “parallel”, “orthogonal”, “center”, “concentric” or “coaxial” are strictly In addition to such an arrangement, it is also possible to represent a state of relative displacement with an angle or a distance such that tolerance or the same function can be obtained.
For example, an expression indicating that things such as “identical”, “equal”, and “homogeneous” are in an equal state not only represents an exactly equal state, but also has a tolerance or a difference that can provide the same function. It also represents the existing state.
For example, expressions representing shapes such as quadrangular shapes and cylindrical shapes represent not only geometrically strict shapes such as quadrangular shapes and cylindrical shapes, but also irregularities and chamfers as long as the same effects can be obtained. A shape including a part or the like is also expressed.
On the other hand, the expressions “comprising”, “comprising”, “comprising”, “including”, or “having” one constituent element are not exclusive expressions for excluding the existence of the other constituent elements.

[First Embodiment]
FIG. 1 is a longitudinal sectional view schematically showing a configuration of a concrete pile with an outer shell steel pipe (hereinafter also referred to as SC pile) 1a according to the first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view taken along the line II-II in FIG. FIG. 3 is a perspective view schematically showing a spiral member 3a applied to the SC pile 1a.

As shown in FIG. 1, the SC pile 1a has the pile main-body part 5, the outer shell steel pipe 7, a pair of end plate 9, and the spiral member 3a.
The pile body 5 is made of concrete. The pile body part 5 has a cylindrical shape and has a hollow part 11 extending in the axial direction. The hollow portion 11 is a cylindrical cavity and penetrates the pile main body portion 5.

  The outer shell steel pipe 7 has a cylindrical shape and covers the outer peripheral surface of the pile body 5. The outer shell steel pipe 7 is made of a metal, for example, a general structural rolled steel material. The outer shell steel pipe 7 has an outer diameter of, for example, 300 mm or more and 1500 mm or less, and the outer diameter of the outer shell steel pipe 7 corresponds to the outer diameter of the SC pile 1a. Moreover, the outer shell steel pipe 7 has a thickness of 4.5 mm or more and 25 mm or less, for example.

  Each of the pair of end plates 9 has a ring shape and covers both end faces of the pile body 5. However, the end plate 9 has an opening continuous with the hollow portion 11, and the hollow portion 11 is not covered with the end plate 9. The end plate 9 is made of metal, and is made of, for example, general structural rolled steel. The pair of end plates 9 are welded to both ends of the outer shell steel pipe 7, respectively.

  The spiral member 3 a is disposed in the hollow portion 11 of the pile body portion 5 and extends spirally around the axis of the pile body portion 5 along the inner peripheral surface of the pile body portion 5.

  According to the SC pile 1a of the first embodiment described above, the spiral member 3a is arranged in the hollow portion 11 of the pile main body portion 5, and the pile main body portion 5 is subjected to a bending moment or shearing force to act on the pile main body portion 5. When the is deformed, the spiral member 3a suppresses a part of the pile main body portion 5 from being peeled off from the inner peripheral surface 13 of the pile main body portion 5. As a result, according to the SC pile 1a described above, the bending strength and the shear strength can be improved as compared with the conventional case.

  Moreover, although the SC pile 1a of 1st Embodiment mentioned above has the outer shell steel pipe 7, it has a bending strength and shear strength higher than a normal concrete pile, for example, a prestressed concrete pile, The spiral member 3a As a result, part of the pile body 5 is prevented from peeling off from the inner peripheral surface 13 of the pile body 5, so that the bending strength and the shear strength can be improved as compared with the prior art.

Preferably, the spiral member 3 a is in contact with the inner peripheral surface 13 of the pile body 5.
According to the said structure, since the spiral member 3a is contacting the inner peripheral surface 13 of the pile main-body part 5, a part of pile main-body part 5 peels off from the inner peripheral surface 13 of the pile main-body part 5 with the spiral member 3a. Is suppressed. As a result, according to the above configuration, the bending strength and the shear strength can be improved as compared with the conventional case.

Preferably, the spiral member 3a is elastically in contact with the inner peripheral surface 13 of the pile main body portion 5 so as to be biased toward the radially outer side of the pile main body portion 5.
According to the said structure, since the spiral member 3a is elastically contacting the inner peripheral surface 13 of the pile main-body part 5 so that it may urge toward the radial direction outer side of the pile main-body part 5, the pile main-body part 5 Even when is deformed, the occurrence of a gap between the inner peripheral surface 13 of the pile body 5 and the spiral member 3a is suppressed. As a result, the spiral member 3a can surely suppress a part of the pile body 5 from being peeled off, and the bending strength and the shear strength can be improved as compared with the related art.
In addition, when the spiral member 3a is elastically contacting the inner peripheral surface of the pile main-body part 5, the spiral member 3a is larger than the diameter or curvature radius of the inner peripheral surface 13 of the pile main-body part 5 in a free state. Has a diameter or radius of curvature.
When the diameter of the spiral member 3a is larger than the diameter of the inner peripheral surface 13 of the pile main body portion 5, in order to arrange the spiral member 3a inside the hollow portion 11, the spiral member 3a is arranged around the axis of the spiral member 3a. The diameter of the spiral member 3a may be reduced by winding or pulling the spiral member 3a in the axial direction of the spiral member 3a, and the spiral member 3a may be inserted into the hollow portion 11 in this state.

Preferably, the spiral member 3a is made of metal, for example, general structural rolled steel. The material of the spiral member 3a is not limited to the general structural rolled steel material, and may be a shape memory alloy or a superelastic alloy. For example, the spiral member 3a is configured by a metal rod having a circular cross-sectional shape.
According to the said structure, since the spiral member 3a is comprised with the metal, it can suppress that a part of pile main-body part 5 peels with a simple structure.
Preferably, the helical pitch P (center-to-center distance) of the helical member 3a is not less than 50 mm and not more than 300 mm.

[Second Embodiment]
FIG. 4 is a perspective view schematically showing a hollow spiral member 3b as a modification of the spiral member 3a of FIG.
In the description after the second embodiment, the configuration different from the preceding embodiment will be mainly described, and the configuration having the same or similar shape or function as the configuration described in the preceding embodiment will be described in the figure. The same reference numerals are attached and explanations are omitted or simplified.

The spiral member 3b is a tube made of resin or rubber, and is bent in a spiral shape. The spiral member 3b is filled with a liquid having a pressure higher than atmospheric pressure, preferably higher than atmospheric pressure, such as water or oil. The tube may contain reinforcing fibers.
According to the above configuration, the rigidity of the spiral member 3b can be increased by filling the spiral member 3b with the liquid. As a result, the spiral member 3b can suppress a part of the pile body 5 from being peeled off with a simple configuration.
The spiral member 3b may be filled with a curable material such as cement, mortar, or grout instead of the liquid. Alternatively, a metal wire, such as a piano wire, may be inserted into the spiral member 3b instead of the liquid. Alternatively, the spiral member 3b may be filled with fibers or the like.

Preferably, as shown in FIG. 5, a pitch determining member 15 that determines the pitch P of the spiral of the spiral member 3b is used together with the spiral member 3b. The pitch determining member 15 includes an extending portion 17 extending in the axial direction of the pile body portion 5 and a plurality of annular portions 19 provided integrally with the extending portion 17. The plurality of annular portions 19 are provided at equal intervals in the axial direction of the pile main body portion 5. For example, the extending part 17 and the annular part 19 are constituted by a fiber band.
According to the said structure, it can suppress that the pitch P of the spiral member 3b becomes excessive by inserting the spiral member 3b in the some cyclic | annular part 19, and one of the pile main-body parts 5 is prevented by the spiral member 3b. It can suppress that a part peels off.
In addition, in FIG. 5, although the two pitch determination members 15 are arrange | positioned so that it may mutually space apart in the diameter direction of the pile main-body part 5, the number of the pitch determination members 15 is limited to two. There may be one or three or more.

[Third Embodiment]
6 and 7 are perspective views schematically showing a spiral member 3c that can be used in place of the spiral members 3a and 3b. As shown in FIGS. 6 and 7, the spiral member 3c is different from the spiral members 3a and 3b in that the spiral member 3c is formed of a metal plate extending in a spiral shape.
In addition, the spiral member 3c of FIG. 7 has shown the state extended in the axial direction of the spiral, and has the clearance gap 21 extended spirally. On the other hand, the spiral member 3c in FIG. 6 shows a contracted state in the axial direction of the spiral, and does not have the spiral gap 21 as shown in FIG.
If it is the spiral member 3c of the state shown in FIG. 6, the inner peripheral surface 13 of the pile main-body part 5 can be covered without a gap. As a result, it is possible to reliably suppress a part of the pile body 5 from being peeled off by the spiral member 3c.

[Fourth Embodiment]
FIG. 8 is a longitudinal sectional view schematically showing the configuration of the SC pile 1b according to the fourth embodiment of the present invention. FIG. 9 is a schematic cross-sectional view along the line IX-IX in FIG. FIG. 10 is a perspective view schematically showing the peeling prevention wall 23 applied to the SC pile 1b.
As shown in FIG.8 and FIG.9, SC pile 1b is further provided with the metal peeling suppression wall 23. FIG. The peeling prevention wall 23 is made of, for example, a general structural rolled steel material. In addition, the material of the peeling suppression wall 23 is not limited to the general structural rolled steel, and may be a shape memory alloy or a superelastic alloy.
The peeling suppression wall 23 is disposed in a state of being sandwiched between the spiral member 3 a and the inner peripheral surface 13 of the pile main body portion 5. The peeling suppression wall 23 is curved along the inner peripheral surface 13 of the pile main body 5 so as to be in contact with the inner peripheral surface 13 of the pile main body 5.
More specifically, the peeling prevention wall 23 is formed in a substantially cylindrical shape by curving a metal plate or cutting a metal tube in the axial direction. For this reason, the peeling prevention wall 23 occupies a part of the hollow part 11, but the remaining part of the hollow part 11 exists inside the peeling prevention wall 23. Thereby, the spiral member 3a can be arrange | positioned inside the peeling suppression wall 23 in the radial direction of the pile main-body part 5. FIG.

  According to the SC pile 1b of the fourth embodiment described above, the peeling suppression wall 23 can cover the inner peripheral surface 13 of the pile body 5 over a wider range, and a part of the pile body 5 is peeled off. Can be suppressed. Under the present circumstances, since it can suppress that the peeling suppression wall 23 leaves | separates from the internal peripheral surface 13 of the pile main-body part 5 with the helical member 3a, it suppresses reliably that a part of pile main-body part 5 peels. Can do.

Preferably, the peeling suppression wall 23 is in elastic contact with the inner peripheral surface 13 of the pile main body 5 so as to urge toward the radially outer side of the pile main body 5.
Thus, when the peeling suppression wall 23 is in elastic contact with the inner peripheral surface 13 of the pile main body part 5 so as to urge toward the radially outer side of the pile main body part 5, the pile main body part 5 is Even when it is deformed, the occurrence of a gap between the inner peripheral surface 13 of the pile main body portion 5 and the peeling prevention wall 23 is suppressed. As a result, it is possible to reliably suppress a part of the pile body 5 from being peeled off by the peeling restraining wall 23, and it is possible to improve the bending proof strength and the shearing proof strength as compared with the related art.
In addition, when the peeling suppression wall 23 is elastically contacting with the inner peripheral surface of the pile main-body part 5, the peeling suppression wall 23 is a free state from the diameter or curvature radius of the inner peripheral surface 13 of the pile main-body part 5. Also have a large diameter or radius of curvature.

Preferably, as shown in FIGS. 8 to 10, the peeling prevention wall 23 includes a first side edge 25 extending in the axial direction of the pile main body 5 and a second side edge extending in the axial direction of the pile main body 5. 27, and the first side edge 25 and the second side edge 27 overlap in the radial direction of the pile body 5.
According to the said structure, since the 1st side edge part 25 and the 2nd side edge part 27 have mutually overlapped, the internal peripheral surface 13 of the pile main-body part 5 can be covered by the peeling suppression wall 23 without gap.

[Fifth Embodiment]
FIG. 11 is a schematic longitudinal sectional view of a prestressed concrete pile (hereinafter also referred to as PC pile) 1c according to the fifth embodiment. The PC pile 1c is different from the SC pile 1a in that it does not have the outer shell steel pipe 7 and has a plurality of PC steel bars 29 provided between the end plates 9 and 9.
Also in the PC pile 1c, the spiral member 3a is disposed in the hollow portion 11 of the pile body portion 5. For this reason, when a pile moment and a shear force act on the pile main-body part 5, and the pile main-body part 5 deform | transforms, it is suppressed that a part of pile main-body part 5 peels from the internal peripheral surface 13 of the pile main-body part 5. Is done. As a result, according to the PC pile 1c, bending strength and shear strength can be improved as compared with the conventional PC pile.
In other words, the present invention is suitable for SC piles, but a PC pile, a high-strength prestressed concrete pile (PHC pile), a reinforced concrete pile (RC pile), etc., includes concrete and has a cylindrical pile body portion having a hollow portion. Applicable to all existing ready-made concrete piles.

In addition, in each embodiment mentioned above, although the case where the spiral-shaped spiral members 3a, 3b, and 3c were used was demonstrated, it is not limited to this shape, You may use a ring-shaped member.
Finally, the present invention is not limited to the above-described embodiments, and includes forms obtained by modifying the above-described embodiments and forms obtained by appropriately combining these forms.

1a, 1b, 1c Concrete pile with shell steel pipe (SC pile)
1d Prestressed concrete pile (PC pile)
3a, 3b, 3c Spiral member 5 Pile main body part 7 Outer shell steel pipe 9 End plate 11 Hollow part 13 Inner peripheral surface 15 Pitch determination member 17 Extension part 19 Annular part 21 Gap 23 Stripping suppression wall 25 First side edge part 27 2 side edge 29 PC steel bar

Claims (8)

A cylindrical pile body including concrete and having a hollow portion;
A spiral member disposed in a hollow portion of the pile body portion and extending spirally around an axis of the pile body portion along an inner peripheral surface of the pile body portion;
Concrete pile characterized by comprising. The concrete pile according to claim 1, wherein the spiral member is in contact with an inner peripheral surface of the pile main body. The concrete pile according to claim 1 or 2, further comprising an outer shell steel pipe covering an outer peripheral surface of the pile main body. The spiral member is in elastic contact with the inner peripheral surface of the pile main body so as to urge toward the radially outer side of the pile main body. A concrete pile according to item 1. The concrete pile according to any one of claims 1 to 4, wherein the spiral member is made of metal. The spiral member is constituted by a hollow tube,
The concrete pile according to any one of claims 1 to 5, wherein the tube is filled with concrete, mortar, grout, water, oil, metal wire, or fiber. The concrete pile according to any one of claims 1 to 6, further comprising a pitch determining member that determines a helical pitch of the spiral member. A metal flaking suppression wall disposed between the spiral member and the inner peripheral surface of the pile body portion;
The peeling suppression wall is curved along the inner peripheral surface of the pile main body so as to contact the inner peripheral surface of the pile main body,
The concrete pile according to claim 1, wherein the spiral member is in contact with an inner peripheral surface of the peeling prevention wall.

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