JP3320049B2 - Manufacturing method of pile - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection structure between a pile and a foundation structure in a pile foundation of a building, and more particularly to a method of manufacturing a pile which can be suitably used in the connection structure.

[0002]

2. Description of the Related Art Conventionally, various buildings have been constructed on pile foundations. The pile foundation is composed of a pile that has been cast or buried in the ground, and a foundation structure provided at the head of the pile, for example, a footing. Several prior arts have been disclosed as to the connection structure between the pile head and the footing.

[0003] Japanese Patent Application Laid-Open No. 9-3918 discloses that a footing body is joined and supported on an upper end side of a pile body which is cast on the ground via a connection structure, and the connection structure has a horizontal sectional size. There is disclosed a connection structure between a pile and a footing, which is formed in a shape gradually reduced in a downward direction. Since this connection structure is formed in a shape in which the size of the horizontal cross section is gradually reduced downward, it is possible to prevent stress such as shearing force from being locally concentrated. Therefore, even if stress such as shear force occurs due to an earthquake or the like, the connection structure,
That is, breakage between the pile and the footing can be prevented. Further, since the pile, the connection structure, and the footing body are integrally provided, breakage can be prevented even if a tensile force acts between the pile and the footing body. However,
In this prior art, the head of the pile is driven into the ground below the ground surface by the length of the connection structure, so that the joint work between the head of the pile and the connection structure after driving is performed underground. And the workability is poor.

Japanese Patent Application Laid-Open No. 64-6418 discloses that in a pile foundation of a building, a concave or convex surface is formed on the lower surface of a foundation structure (for example, footing) of the building, and a smaller surface is formed on this surface. A cover with a large number of concave or convex surfaces is provided, a convex or concave surface is formed on the head of the pile, and a cover with a large number of smaller convex or concave surfaces is provided on this surface. A pin joint structure is disclosed in which these covers are joined to each other to form a pin structure, and a floating resistor is disposed at the center of the two covers.
Since the pin joint structure is provided with the floating resistor, even if a tensile force acts between the pile and the footing, the footing does not float from the head of the pile. However,
Since the mutual displacement between the pile and the footing is restricted by the presence of the floating resistor, there is a problem that the operation of the pin structure is suppressed. There is also a problem that a great deal of labor and time are required to provide the floating resistor.

As another connection structure between the pile and the footing, the lower part of a cage-shaped reinforcing bar is inserted into the space of the head of the pile formed in a hollow cylindrical shape, and the upper part of the cage reinforcing bar is connected to the pile. Projecting upward from the head of the pile, filling the hollow part of the pile head with so-called filling concrete, covering the lower part of the basket rebar with filling concrete, and further covering the upper part of the basket rebar with concrete to form a footing. There is known a connection structure between a pile and a footing, which integrally form the filled concrete and the footing.

[0006]

Generally, when a building is tilted at the time of occurrence of an earthquake, a typhoon, or the like, a pulling force acts on a pile of a pile foundation. Usually, the pile length is long and the contact area between the pile and the ground is large, so that the adhesion resistance between the pile and the ground, in other words, the pull-out resistance of the pile is large. Therefore, the breakage of the pile foundation depends on the breakage resistance of the connection between the pile and the footing, in other words, the joint strength between the pile and the footing. At the connection between the pile and the footing, the pull-out force acting on the pile acts as a tensile force, so the breakage resistance to the tensile force at the connection between the pile and the footing, in other words, the tensile strength of the joint between the pile and the footing Is important.

As described above, in the prior arts disclosed in JP-A-9-3918 and JP-A-64-6418, the tensile strength of the joint between the pile and the footing is sufficiently ensured. On the other hand, in the connection structure of the system in which the cage rebar is inserted into the pile to fill the filling concrete, the tensile strength of the joint between the filling concrete and the footing is sufficiently ensured, but the filling concrete is provided. There is a problem that the tensile strength at the joint between the pile and the inner peripheral surface of the pile is relatively low and unstable. That is,
There is a problem that the pull-out resistance of the middle-packed concrete, which is the breakage resistance to the tensile force between the middle-packed concrete and the pile, is smaller and more variable than the pull-out resistance of the pile. Therefore, when a pulling force is applied to the pile, there is a possibility that the pile foundation may be damaged by pulling out the filling concrete.

The present inventors have conducted various studies on this problem. As a result, as shown in FIG. 16, the problem is that the contact interface between the inner peripheral surface of the pile 1 and the concrete 3 is smooth. Was found to be caused by The present invention has been made based on this finding, and aims to solve the problem by improving the contact interface.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for efficiently manufacturing a pile capable of increasing the pull-out resistance of the concrete filled into the pile and increasing the joining strength between the pile and the footing. It is to provide.

[0010]

SUMMARY OF THE INVENTION The present invention relates to a method of manufacturing a reinforced concrete pile having a substantially hollow cylindrical shape and provided in the ground, and extending over the entire length along the axis of the pile. And, a plurality of long axial reinforcing bars arranged at intervals in the circumferential direction around the axis, and a spiral reinforcing bar or a plurality of spiral reinforcing bars that surround the plurality of long axial reinforcing bars and are wound around the axis. And a reinforcing rod assembly composed of a plurality of long axial reinforcing rods and a spiral reinforcing rod or a plurality of band reinforcing rods is covered with concrete, and the overall shape is substantially adjusted. It is characterized in that it is formed so as to have a hollow cylindrical shape, and in the state where the concrete is unhardened, irregularities extending in the circumferential direction are formed over a predetermined length on the inner peripheral surface of the head of the pile. It is a method of manufacturing a pile.
According to the present invention, a reinforcing bar assembly including a plurality of long axial reinforcing bars is formed, and the reinforcing bar assembly is covered with, for example, concrete sprayed from a rotary nozzle, so that the entire shape becomes substantially hollow cylindrical. In a state in which the concrete is uncured, for example, a mold having irregularities is pressed against the inner peripheral surface of the head of the pile to form irregularities extending in the circumferential direction. Can be manufactured.
Further, in the present invention, a tensile force is applied to the plurality of long axial reinforcing bars. According to the present invention, the plurality of long axial reinforcing bars are provided with a tensile force before the concrete is hardened, and the tensile force is released after the concrete is hardened, so that a compressive force can be applied to the concrete. . The connection structure of the pile manufactured in this way is a pile provided substantially vertically in the ground and having a concave fitting part opened upward at least at the head, and the inner peripheral surface of the concave fitting part of the head. A stake extending in a direction intersecting the up-down direction and being provided vertically adjacent to each other, wherein the undulation is a pile extending in the circumferential direction, and an axial reinforcing bar extending in the up-down direction, The lower part is inserted into the concave fitting part of the head, and the upper part is provided so that the upper part protrudes above the head of the pile, and the reinforcing rod extends upward from the head of the pile and is filled over the axial reinforcing rod. A concrete structure filled with concrete and a concrete structure which is filled in close contact with the inner peripheral surface of the concave fitting part of the head of the pile and covers the reinforcing steel in the axial direction. Are integrally formed.

[0011] An uneven portion extending in the circumferential direction is formed on the inner peripheral surface of the concave fitting portion of the head of the pile, and furthermore, the concrete is filled in close contact with the inner peripheral surface of the concave fitting portion. Therefore, when a drawing force acts on the filled concrete, the pulling resistance of the filled concrete depends on the shear strength of the convex portion of the filled concrete. Normally, the shear strength of concrete is larger than the adhesive force between a pile in which uneven portions are not formed and a filled concrete. Therefore, the formation resistance of the unevenness can increase the pull-out resistance of the filled concrete as compared with the prior art in which the unevenness is not formed. Moreover, since the filling concrete and the foundation structure are formed integrally via the axial reinforcing steel, the joining strength between the filling concrete and the foundation structure can be increased. Therefore, the joining strength between the pile and the foundation structure can be increased as compared with the prior art.

A receiving member which is inserted into the concave fitting portion of the head of the pile and closes a lower portion of the filling area of the filled concrete, a lower end connected to the receiving member, and an upper end of which is attached to the head of the pile; A concrete receiver having a piece.

Since the concrete-filled concrete receiving body is provided in the concave fitting portion of the head of the pile, it is possible to prevent the concrete-filled concrete from falling down and to form the concrete-filled concrete to a desired length. be able to.

A plurality of the axial reinforcing bars are provided at intervals in the circumferential direction about the axis of the pile, and a spiral reinforcing bar or a plurality of band reinforcing bars are fixed to the plurality of axial reinforcing bars, and the overall shape is substantially the same. It is formed in a basket shape.

[0015] Since the spiral reinforcing bar or the plurality of band reinforcing bars are fixed to the plurality of axial reinforcing bars, the joining strength between the filling concrete and the substructure can be increased.

The base structure is a footing, and a load receiving portion extending horizontally is integrally formed at an upper portion of the footing, and a bottom area of the footing is larger than a sectional area of the load receiving portion. Is formed.

Since the footing is formed so that the bottom area thereof is larger than the cross-sectional area of the load receiving portion, the vertical load from above can be evenly dispersed and transmitted to the pile, and the vertical load can be safely secured by the pile. Can be supported.

[0018] A concrete pile having at least a concave portion formed on the head portion outwardly in the axial direction, wherein the concave portion of the head portion has an inner peripheral surface extending in a direction intersecting the axial direction. An uneven portion extending and provided adjacent to the axial direction is formed, and the uneven portion extends in the circumferential direction.

Since the concave-convex portion extending in the circumferential direction is formed on the inner peripheral surface of the concave fitting portion of the head of the pile, the pull-out resistance of the filled concrete can be increased, for example, when filling the filled concrete.

In the concrete of the pile, a plurality of long axial reinforcing bars extending over the entire length along the axis of the pile and arranged circumferentially at intervals around the axis of the pile, A spiral rebar or a plurality of belt rebars, which surround the plurality of long axial rebars around the axis of the pile, are embedded.

[0021] Since a plurality of long axial reinforcing bars and the like are embedded in the concrete of the pile, the strength of the pile can be increased.

A compressive force is applied to the concrete of the pile in the axial direction of the pile.

Since the concrete of the pile is given a compressive force, even if a tensile force is applied to the concrete, the tensile force can be offset and the concrete can be prevented from being damaged.

The pile is characterized in that it has a substantially hollow cylindrical shape.

Since the pile has a hollow cylindrical shape, the weight of the pile can be reduced. Also, if the tip of the pile is formed open,
The driving resistance of the pile can be reduced.

[0026]

[0027]

[0028]

[0029]

[0030]

FIG. 1 is a front sectional view showing a simplified structure of a pile connection structure according to an embodiment of the present invention, and FIG. 2 is a pile having the pile connection structure shown in FIG. FIG. 3 is a simplified front view showing the entire configuration of the foundation, and FIG. 3 is a partial cross-sectional view taken along the line III-III in FIG. 2.

If the ground is soft, the building is built on a pile foundation. The pile foundation consists of a pile 8 driven into the ground and a pile 8
And a footing 9 which is a basic structure formed on the head of the vehicle. The substructure may be an underground beam or the like. The pile 8 is, for example, a high-strength prestressed concrete pile (abbreviated as a PHC pile), and its tip is driven almost vertically through the soft ground 10 until it reaches the strong ground 11. The pile 8 may be configured to be embedded in the ground. The building is supported by a footing 9, and a load from the building is supported by one or more (four in the present embodiment) piles 8 via the footing 9.

The pile 8 has a substantially hollow cylindrical shape, and the axis of the pile 8 when driven into the ground is substantially a vertical axis. In a hollow portion of the head of the pile 8 (hereinafter, referred to as a pile head hollow portion 8a), a lower portion of a reinforcing rod generally formed in a cage shape (hereinafter, referred to as a cage reinforcing bar 13) is inserted. Basket rebar 13
Is projected above the head of the pile 8 and is embedded in the footing 9. A concrete receiver 14 is mounted below the basket reinforcing bar 13 in the pile head hollow portion 8a, and concrete is filled in the pile head hollow portion 8a so as to cover a lower portion of the basket reinforcing bar 13. Hereinafter, the concrete filled in the hollow portion 8a of the pile head is referred to as a filling concrete 15. The pile 8, the footing 9, the cage reinforcing bar 13,
Concrete receiver 14 and filling concrete 15
Form a connection structure for the pile 8. The connection structure of the pile 8 will be further described later.

The footing 9 is a massive reinforced concrete extending upward from the head of the pile 8, and a lower reinforcing bar 16, an upper reinforcing bar 17, and a side reinforcing bar 18 are arranged therein. A load receiving portion 19 extending laterally is formed integrally with an upper portion of the footing 9, and a bottom area of the footing 9 is formed to be larger than a cross-sectional area of the load receiving portion 19. As a result, the footing 9 can evenly distribute the vertical load from the building above and transmit it to the pile 8, and the pile 8 can safely support the load of the building.

FIG. 4 is a partial cross-sectional view showing a simplified configuration of the pile 8 shown in FIG. 1, and FIG. 5 is a cross-sectional view taken along the line VV of FIG. An uneven portion 23 extending annularly in the circumferential direction is formed on the inner peripheral surface of the pile head hollow portion 8 a of the pile 8. As shown in FIG. 6, the uneven portion 23 has a ridge 24 and a concave groove 2.
5 A plurality of ridges 24 and concave grooves 25 are provided adjacent to each other along the axis 26 of the pile 8. The pitch p1 at the top of the ridge 24 and the pitch p2 at the bottom of the groove 25 may or may not be the same. Axis 8 of pile 8
6, a curve 27 connecting the top of the ridge 24 and the bottom of the adjacent groove 25 is formed in a smooth circular arc shape so as to make the filling concrete 15 flow easily. Extends in a direction crossing the axis 26. The uneven portion 23 extends toward the tip 8b of the pile 8 along the axis 26, and is formed over a predetermined length L1. The diameter D1 of the circle connecting the tops of the ridges 24 is uniformly formed along the axis 26 and is equal to the inner diameter D1 of the pile 8. The unevenness depth ΔD1 of the uneven portion 23, which is the radial distance between the top of the ridge 24 and the bottom of the concave groove 25, is:
The pitches p1 and p2 at the top and bottom are set to predetermined values as described later.

In the concrete of the pile 8, for example, a plurality of (in this embodiment, eight) PCs, which are long axial reinforcing bars, are provided.
A steel rod 33 and a spiral rebar 34 are embedded. PC
The steel rod 33 is a high-strength steel rod for applying prestress to prestressed concrete (abbreviated as PC), extends over the entire length along the axis 26 of the pile 8, and extends in the circumferential direction around the axis 26. The bars are arranged at intervals. The spiral reinforcing bar 34 is wound around the axis 26 of the pile 8 in a spiral around the plurality of PC steel bars 33 as shown in FIG. The strength of this PHC pile 8 is 800 kg
High strength of f / cm ² or more is exhibited. Pile 8 is PH
Not limited to C pile, 500kgf / cm ²
Prestressed concrete pile with the above strength (P
C pile), a reinforced concrete pile to which no prestress is introduced, or a concrete pile in which no reinforcing steel is embedded. Also, the pile 8 of the present embodiment
Has a hollow cylindrical shape, but is not limited to this, and is not necessarily hollow over the entire length of the pile if at least a concave fitting part that is open upward is formed at the head of the pile. Good. In this case, the uneven portion is formed in a concave fitting portion of the head of the pile.

FIG. 8 is a simplified front view showing the configuration of the cage reinforcing bar 13 shown in FIG. 1, and FIG. 9 is a plan view of FIG.
The cage reinforcing bar 13 is a reinforcing bar assembly including a plurality (eight in the present embodiment) of axial reinforcing bars 36 and a plurality of (ten in the present embodiment) band reinforcing bars 37, and has a substantially cylindrical cage as a whole. It is formed in a shape. The cage rebar 13 is connected to the axis 26 of the pile 8 by the axis.
And inserted into the hollow portion 8a of the pile head. The axial reinforcing bars 36 are arranged at intervals around the axis 26 of the pile 8 in the circumferential direction. The band reinforcing bar 37 is annularly wound around the axis 26 of the pile 8 around the plurality of axial reinforcing bars 36. The axial reinforcing bar 36 and the belt reinforcing bar 37 are fixed by welding or the like.

FIG. 10 is a simplified perspective view showing the structure of the concrete receiver 14 shown in FIG. The concrete receiver 14 includes a receiving member 39 and a plurality (four in the present embodiment) of support pieces 40. The receiving member 39 is a dish-shaped member made of a synthetic resin, and is inserted into the hollow portion 8a of the pile head to close the lower part of the filling area of the filling concrete 15.
The support piece 40 is made of a steel wire, and the lower end is connected to the receiving member 39, and the bent upper end is attached to the head of the pile 8. Thereby, when filling the filling concrete 15, the filling concrete 15 can be prevented from falling down, and the filling concrete 15 can be formed to a desired length.

Referring again to FIG. 1, the connection structure of the pile 8 is formed as follows. (1) The pile 8 is driven into the ground. (2) The head of the pile 8 is cut to a predetermined length, or the PC steel bar 33 is pulled out from the head of the pile 8. (3) The receiving member 39 of the concrete receiver 14 is inserted into the hollow portion 8a of the pile head, and the support piece 40 is attached to the upper end surface of the head of the pile 8 after being pulled out. (4) The lower reinforcing bar 16, the upper reinforcing bar 17, and the side reinforcing bar 18 of the footing 9 (hereinafter sometimes collectively referred to as a footing reinforcing bar) are arranged, and the form frame of the footing 9 is assembled. (5) Insert the lower part of the cage reinforcing bar 13 into the pile head hollow part 8a,
The upper part of the cage rebar 13 is projected above the head of the pile 8 after being extended and fixed to the lower reinforcement 16 of the footing 9 and the extended PC steel rod 33. (6) Concrete is poured into the hollow portion 8a of the pile head and filled to form the filling concrete 15. As a result, as shown in FIG. 11, the filling concrete 15 adheres to the ridges 24 and the concave grooves 25 of the uneven portion 23, and
The lower part of the cage reinforcing bar 13 is covered. (7) Concrete is poured into the frame of the footing 9 and filled therein, and the upper part of the basket reinforcing bar 13, the footing reinforcing bar and the P
The footing 9 is formed integrally with the filling concrete 15 so as to cover the C steel bar 33 and the like. The embedding depth L5 of the head of the pile 8 into the footing 9 is set to 100 mm.

As described above, the filling concrete 15 and the footing 9 are formed by the cage reinforcing bar 13, the footing reinforcing bar, and the P
They are integrally connected via a C steel bar 33 or the like. Further, the inner peripheral surface of the pile head hollow portion 8a and the filling concrete 15 are connected via an uneven portion 23 formed on the inner peripheral surface.
Therefore, the joint strength between the pile 8 and the footing 9 increases, and the pile 8 and the footing 9
Even if a tensile force acts between them, breakage between the pile 8 and the footing 9 can be prevented.

As described in the step (6), the filled concrete 15 is filled in the pile head hollow portion 8a,
It is in close contact with the ridges 24 and the concave grooves 25 of the uneven portion 23. Accordingly, the pull-out resistance to the pull-out force after the hardened concrete 15 hardens depends on the shear strength at the shear fracture surface indicated by the dotted line 43 in FIG. This shear fracture surface
Since this is a surface connecting the bases of the concave portions of the hollow concrete 15, the pull-out resistance is substantially equal to the shear strength of the hollow concrete 15. On the other hand, the pull-out resistance of the related art in which the uneven portion 23 is not formed is the adhesion strength between the inner peripheral surface of the pile 1 and the concrete 3 as shown in FIG.
Generally, the shear strength of concrete is greater than the bond strength. Also, the variation in shear strength is smaller than the variation in adhesion strength that is susceptible to the working conditions. Therefore,
In the present embodiment, the pull-out resistance when a pull-out force acts on the filling concrete 15 can be increased and stabilized compared to the prior art. The uneven portion 2
3, the pitches p1 and p of the top and bottom portions
No. 2 affects the shear strength and the ease of pouring concrete. Therefore, these values are appropriately set in advance based on experiments.

Next, a method of manufacturing the pile 8 will be described. The pile 8 is manufactured by the following steps.

(A) A plurality (eight in the present embodiment) of the PC steel rods 3 extending over the entire length along the axis 26 of the pile 8
13 are prepared and arranged at equal intervals in the circumferential direction around the axis as shown in FIGS. 13 (1) and 13 (2). (B) The spiral rebar 34 is prepared, and FIG.
As shown in (2), the plurality of PC steel bars 33 are spirally wound around the axis and wound around the axis, and the rebar assembly 45 is assembled so that the overall shape is substantially a cylindrical cage. When assembling the reinforcing bar assembly 45, an annular belt reinforcing bar may be used instead of the spiral reinforcing bar 34. (C) Apply a tensile force to each PC steel rod 33 of the reinforcing bar assembly 45. The magnitude of the tensile force is set according to the desired amount of prestress. (D) As shown in FIG. 14, the reinforcing bar assembly 45 is inserted into the cylindrical formwork 46, and the rotary nozzle 47 is provided on the axis 26 of the pile 8, that is, on the axis of the reinforcing bar assembly 45.
7 is rotated while moving along the axis, and concrete is sprayed from the rotary nozzle 47 to cover the reinforcing bar assembly 45 by centrifugal force, and the pile 8 is formed in a substantially hollow cylindrical shape. (E) In a state where the concrete of the pile 8 is uncured as shown in FIG.
And a pair of concave and convex molds 50 are pressed against the inner peripheral surface of the pile head hollow portion 8a by an air cylinder 51, and the pair of concave and convex molds 50 are inserted.
Is rotated to form an annular uneven portion 23 extending in the circumferential direction on the inner peripheral surface of the pile head hollow portion 8a. The uneven portion 23 may be formed in an annular shape over the entire circumference in this manner, or may be formed in a state of being divided in the circumferential direction. In addition, the concavo-convex part 49 is rotated while moving the concavo-convex forming machine 49 along the axis of the pile 8, and
May be formed in a spiral shape. (F) After the concrete of the pile 8 is hardened, the tensile force is released.

As described above, the pile 8 is formed into a substantially hollow cylindrical shape by utilizing the centrifugal force, and the pile head hollow portion 8a is formed.
Since the uneven portion 23 is formed on the inner peripheral surface of the slab using the uneven shape, the pile 8 having the uneven portion 23 can be efficiently manufactured. In addition, a tensile force is applied to the PC steel bar 33 before the concrete is hardened, and the tensile force is released after the concrete is hardened, so that a compressive force can be applied to the concrete.

As described above, in this embodiment, the uneven portion 23 is formed on the inner peripheral surface of the pile head hollow portion 8a, and the uneven portion 2 is formed.
Although the diameter of the circle connecting the tops of the three ridges 24 is configured to be uniform along the axis 26 of the pile 8, in another embodiment of the present invention, the diameter of the circle is You may comprise so that it may become large as it goes to the front-end | tip part 8b of the pile 8 from the head along the axis 26. As a result, the pull-out resistance of the piled concrete having such a configuration is higher than the pull-out resistance of the piled concrete 15 having uniform uneven portions. Such formation of the uneven portion 23 can be realized by pressing the inclined uneven mold 50 against uncured concrete. Also, without forming the uneven portion 23 on the inner peripheral surface of the pile head hollow portion 8a, the diameter of the inner peripheral surface of the pile head hollow portion 8a extends from the head of the pile 8 to the pile 8 over the filling region of the filled concrete. You may comprise so that it may become large as it goes to the front-end | tip part 8b. This can likewise increase the pull-out resistance of the filled concrete. Further, in the present embodiment, the filling concrete 15 and the footing 9 are configured so as to be integrally formed with the basket reinforcing bar 13 interposed therebetween.
Alternatively, the axial reinforcing bar 36 may be used, and the filling concrete 15 and the footing 9 may be integrally formed with the axial reinforcing bar 36 interposed therebetween.

[0045]

According to the first aspect of the present invention, a rebar assembly including a plurality of long axial rebars is formed, and the rebar assembly is covered with, for example, concrete injected from a rotary nozzle to form an overall shape. It is formed so as to have a substantially hollow cylindrical shape, and in a state where the concrete is uncured, for example, a mold having irregularities is pressed to form irregularities extending in the circumferential direction on the inner peripheral surface of the head. As a result, the pile can be manufactured efficiently.

According to the second aspect of the present invention, since a tensile force is applied to the plurality of long axial reinforcing bars, a compressive force can be applied to concrete.

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[Brief description of the drawings]

FIG. 1 is a simplified front cross-sectional view showing the configuration of a pile connection structure according to an embodiment of the present invention.

FIG. 2 is a simplified front view showing an overall configuration of a pile foundation having the pile connection structure shown in FIG.

FIG. 3 is a partial cross-sectional view taken along the line III-III of FIG. 2;

FIG. 4 is a partial cross-sectional view showing a simplified configuration of a pile 8 shown in FIG.

FIG. 5 is a cross-sectional view taken along the line VV of FIG. 4;

6 is an enlarged cross-sectional view of the uneven portion 23 shown in FIG.

FIG. 7 is a front view showing a state of a spiral rebar 34 wound around a plurality of PC steel bars 33.

FIG. 8 is a simplified front view showing the configuration of the cage reinforcing bar 13 shown in FIG.

FIG. 9 is a plan view of FIG.

FIG. 10 is a simplified perspective view showing a configuration of a concrete receiver 14 shown in FIG. 1;

FIG. 11 is a cross-sectional view showing a filling state of the filling concrete 15 of the present invention.

FIG. 12 is a sectional view for explaining a shear fracture surface of the filling concrete 15.

FIG. 13 is a diagram showing a configuration of a reinforcing bar assembly 45 embedded in a pile 8.

FIG. 14 is a cross-sectional view illustrating a method of forming the pile 8 into a hollow cylindrical shape.

FIG. 15 shows an uneven portion 23 on the inner peripheral surface of the pile head hollow portion 8a of the pile 8.
FIG. 4 is a cross-sectional view illustrating a method of forming a semiconductor device.

FIG. 16 is a cross-sectional view showing the state of filling of a conventional medium-filled concrete.

[Explanation of symbols]

 1,8 Piles 3,15 Filled concrete 9 Footing 13 Basket reinforcement 14 Concrete receiver 16 Lower reinforcement 19 Load receiving part 23 Irregularity part 33 PC steel rod 34 Spiral reinforcement 45 Reinforcement assembly

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) E02D 27/12

Claims (2)

(57) [Claims] 1. A method for manufacturing a reinforced concrete pile having a substantially hollow cylindrical shape and provided in the ground, comprising: a slab extending along the axis of the pile over its entire length; A plurality of long axial reinforcing bars arranged at intervals in the direction, and a spiral reinforcing bar or a plurality of band reinforcing bars wound around the axis so as to surround the plurality of long axial reinforcing bars have an overall shape. Assemble in a roughly cage shape, cover a reinforcing bar assembly consisting of a plurality of long axial reinforcing bars and a spiral reinforcing bar or a plurality of band reinforcing bars with concrete, and make the overall shape substantially a hollow cylindrical shape. A method of manufacturing a pile, comprising forming irregularities extending in a circumferential direction on an inner peripheral surface of a head of a pile over a predetermined length in a state where concrete is uncured. 2. The method for manufacturing a pile according to claim 1, wherein a tensile force is applied to the plurality of long axial reinforcing bars.