JP2002115256A - Structure for head part of foundation pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure for a head part of a foundation pile, enabling an improvement in workability, economical execution, and the easy and reliable mounting of a joining reinforcing bar for joining the pile head part and a footing to the head part of the foundation pile. SOLUTION: A plurality of connecting fittings 2 are protrusively installed on the outer periphery of the upper end of a steel pipe pile 1 at prescribed intervals in the peripheral direction of the pile 1. In the connecting fittings 2, there are protrusively installed the respective joining reinforcing bars 4 for joining the pile head part of the pile 1 to the footing 3 constructed on the upper side of the head part. The connecting fitting 2 has an arc-shaped part 2a below, and the reinforcing bar 4 is formed in a U shape corresponding to the arc- shaped part 2a of the connecting fitting 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a foundation pile head such as a steel pipe pile or a steel pipe concrete pile or a concrete pile constructed in the ground as a foundation pile of a building.

[0002]

2. Description of the Related Art As the foundation of a reinforced concrete structure, the strength of the ground immediately below a footing or a foundation slab (hereinafter referred to as "footing") cannot be expected very much. There is known a pile foundation that transmits a pile to the ground.

[0003] In this case, as a foundation pile, for example, a steel pipe pile or a steel pipe concrete pile is used, and the pile heads are integrally joined to the footing. Heretofore, as a method of integrally joining the pile head of the foundation pile with the footing, for example, as shown in FIG.
5 is a reinforcing bar cage system in which a reinforcing bar is projected as a connecting reinforcing bar 21 for connecting the pile head and the footing to the upper end of the pile.
As shown in FIG. 5 (b), a beard bar system in which a joint reinforcing bar 21 is directly welded to the outer periphery of the upper end of the foundation pile 20 to protrude, FIG.
As shown in (c), there is known a coupler system in which a threaded coupler or a nut 22 is welded to an outer periphery of an upper end portion of a foundation pile 20 and a joining reinforcing bar 21 is screwed to the coupler or the nut 22 to project therefrom. ing.

[0004] In either method, the joint head 21 of the foundation pile 20 and the footing are integrally joined by fixing the joint reinforcing bar 21 projecting from the upper end of the foundation pile 20 in the concrete of the footing. Is done.

[0005]

However, in the case of the reinforced cage system, the reinforced cage serving as the joining reinforcing bar 21 is made of a steel pipe pile 20a.
Since it is inserted into the concrete 20b filled in the upper end of the steel bar and protruded, the space for reinforcing bars is narrowed and the reinforcing bars are apt to be overcrowded. For this reason, not only was the construction difficult, but there were also problems such as poor mechanical performance.

Further, the beard bar method has a problem that it is difficult to assure the quality of field welding, and the coupler system can solve the above-mentioned problems of the rebar cage method and the beard bar method, but increases the cost. And other issues.

In the case of the coupler system, when a polygonal column-shaped coupler is directly welded to the outer periphery of the steel pipe pile, one side of the coupler 22 is connected to the side of the steel pipe pile 20a as shown in FIG. , And both ends are welded to the steel pipe pile 20a, but this welding is extremely troublesome.

Moreover, even if the coupler 22 can be welded to the outer periphery of the steel pipe pile 20a, the distance s between the welded portions at both ends is extremely short, so that when the foundation pile 20 receives a force P in the horizontal direction, the moment resistance is reduced. However, there is a problem that it is small and easily becomes a mechanical weak point.

A method for solving such a problem of the coupler system is disclosed in, for example, JP-A-11-247184. In the method described in this publication, as shown in FIG. 5D, a joint reinforcing bar 21 composed of a screw reinforcing bar is used by using a normal steel pipe 23 instead of a coupler (connector with a screw hole).
In order to fix the steel pipe 23, the cost is improved as compared with the coupler method.
Not only is it more difficult than in the case of welding the polygonal coupler 22, but the weld is still a mechanical weak point.

Further, unlike the coupler system, the steel pipe 23
In order to penetrate and fix the screw rebar as the joint rebar 21, it is necessary to fasten the fixing nuts 24 and 25 to the joint rebar 21 from the lower end and the upper end of the steel pipe 23, respectively. It is not easy to fasten the lower fixing nut 24 to the joint reinforcing bar 21 after attaching the 23.

The axial force acting on the joint reinforcing bar 21 is transmitted to the steel pipe 23 via the fixing nuts 24 and 25. However, since the sectional force of the steel tube 23 is substantially the same as the axial force of the joint reinforcing bar 21, it is considerably large. There is a problem that it requires a thick steel pipe and is not realistic.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a joining reinforcing bar can be easily and reliably attached to a head of a foundation pile for joining the pile head and a footing. An object of the present invention is to provide a structure of a foundation pile head capable of improving workability and economic construction.

[0013]

According to a first aspect of the present invention, there is provided a foundation pile head having a structure in which a joint reinforcing bar is fixed to a connection fitting attached to an outer periphery of the pile head.
The connection fitting having an arcuate portion below has a U-shaped joining rebar corresponding to the arcuate portion of the connection fitting, which is nationally defined.

According to a second aspect of the present invention, there is provided a foundation pile head structure according to the first aspect, in which groove-shaped portions on both sides and a lower end of the connection fitting are engageable with joint reinforcing bars. It is characterized by being formed continuously from the portion to the lower end.

According to a third aspect of the present invention, there is provided a structure of a foundation pile head according to the first or second aspect, wherein reinforcing bar locking portions are provided at both side portions and a lower end portion of the connection fitting. Is formed continuously.

According to a fourth aspect of the present invention, there is provided a structure of a foundation pile head according to the second aspect, wherein a reinforcing bar engaging portion is continuous from both sides and a lower end to both sides and a lower end of the connection fitting. The rebar engaging portion is formed to have a substantially L-shaped cross section, and the inner periphery thereof is formed to have a substantially groove-shaped cross section continuous with the groove portion.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 of the Invention 1 and 2
Shows an example of the structure of the foundation pile head according to the present invention. In the figure, a connection fitting 2 is provided at predetermined intervals in the circumferential direction of the steel pipe pile 1 on the outer periphery of the upper end of the steel pipe pile 1 constructed as the foundation pile. A plurality of projections are provided, and joint bars 4 for joining the pile head of the steel pipe pile 1 and the footing 3 installed on the upper side thereof are projected from the connection fitting 2 respectively.

The connection fitting 2 is formed in a block shape having a predetermined thickness, the upper end thereof is horizontal, the both sides are vertical,
The lower end portion is formed in an arc shape (hereinafter, referred to as “arc-shaped portion 2a”) that is continuous from both sides and protrudes downward at a predetermined curvature.

On both sides of the connection fitting 2, there are groove portions 2b having a substantially U-shaped cross section which open laterally, and groove portions 2b having a substantially U-shaped cross section which open downward are formed on the lower end portion. Each groove-shaped portion 2b is formed, and is continuous from both sides to the lower end. A plurality of mounting holes 2c are formed in the center of the connection fitting 2 at predetermined intervals in the vertical direction.

The connection fitting 2 thus formed is connected to the steel pipe pile 1.
And is fixed by a plurality of mounting bolts 5 penetrating the mounting hole 2c and the mounting hole 1a formed in the steel pipe pile 1.

The joint reinforcing bar 4 is formed in a U-shape with a predetermined curvature corresponding to the arc-shaped portion 2a extending from both sides to the lower end of the connection fitting 2. In addition, the joint reinforcing bar 4 has a U-shaped portion 4.
a is locked to the arc-shaped portion 2a of the connection fitting 2, and the U-shaped portion 4
The straight portions 4b, 4b on both sides continuing from a are vertically raised upward along both side portions of the connection fitting 2, and further protrude upward from both ends of the connection fitting 2 by a predetermined length.

Then, a washer 6 is attached to the linear portions 4b, 4b of the joint reinforcing bar 4, and thereafter, fixing nuts 7 are screwed together. In this way, the joint reinforcing bar 4 is connected to the connection fitting 2
And protrudes from the outer periphery of the steel pipe pile 1 through the center. It should be noted that a screw rebar or the like is used for the joint rebar 4 in addition to the round bar.

In such a configuration, the axial force acting on the joining rebar 4 is reliably transmitted to the connection fitting 2, the mounting bolt 5, and the steel pipe pile 1.

Embodiment 2 of the Invention 3 (a) to 3 (c)
Shows another example of the structure of the foundation pile head according to the present invention. In the example described with reference to FIGS.
Rebar engaging portions 2d are formed continuously from both sides to the lower end in a brim shape at both sides and the lower end.

Since the reinforcing bar locking portions 2d are continuously formed on both sides and the lower end of the connecting fitting 2, the joint reinforcing bar 4 does not come off from the connecting fitting 2, and the footing 3
The stress transmitted from the upper structure is reliably transmitted to the steel pipe pile 1.

Embodiment 3 of the Invention 4 (a) to 4 (c)
Shows another example of the structure of the foundation pile head according to the present invention. In the example described with reference to FIGS.
Reinforcing bars 2d are formed on both sides and a lower end of each of them. In particular, the reinforcing bars 2d on both sides are formed in a substantially L-shaped cross section, and the inner periphery thereof is substantially continuous in cross section with the groove 2a. It is formed in a U-shape.

Since the reinforcing bar locking portions 2d on both sides are formed in this manner, the joint reinforcing bar 4 can be more reliably held, and the stress of the upper structure transmitted from the footing 3 is transmitted to the steel pipe pile 1. Is reliably transmitted.

[0028]

The present invention has been described above. In particular, the lower end of the connection fitting attached to the outer peripheral portion of the foundation pile is formed in an arc shape that is continuous from both sides and projects downward. Since the rebar is formed in a U-shape corresponding to the arc shape of the lower end of the connection fitting, the joining rebar locks the U-shaped part to the lower end of the connection fitting and extends the straight portions on both sides upward. After that, the joint reinforcement can be easily and securely attached to the connection fitting by tightening the fixing nut to the straight part on both sides, and the connection fitting is bolted rather than welded to the outer periphery of the foundation pile, The connection fitting can also be easily and reliably attached, thereby improving workability and economical construction.

Further, since a groove-like portion in which the joining rebar can be engaged and a rebar engaging portion are formed continuously from both sides to the lower end, the joining rebar is formed on both sides and the lower end of the connection fitting. And the stress of the superstructure transmitted from the footing can be reliably transmitted to the foundation pile.

[Brief description of the drawings]

FIG. 1 shows a structure of a foundation pile head, (a) is a partial front view of a foundation pile head showing a mounting state of a connection fitting and a joint reinforcing bar,
(B) is a plan view, and (c) is a cross-sectional view taken along the line II in (a).

FIG. 2 is a partially exploded perspective view of a foundation pile head showing a mounting state of a connection fitting and a joint reinforcing bar.

3A and 3B show a structure of a foundation pile head, wherein FIG. 3A is a partial front view showing an attached state of a connection fitting, FIG. 3B is a sectional view taken along the line II of FIG. 3A, and FIG. It is a perspective view of.

4A and 4B show a structure of a foundation pile head, where FIG. 4A is a partial front view showing an attached state of a connection fitting, FIG. 4B is a sectional view taken along the line II in FIG. It is a perspective view of.

5 (a) to 5 (c) are longitudinal sectional views, FIG. 5 (d) is a partial side view, and FIG. 5 (e) is a plan view of a coupler.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steel pipe pile 2 Connection metal fitting 2a Arc-shaped part 2b Groove-shaped part 2c Attachment hole 2d Rebar anchoring part 3 Footing 4 Joining reinforcing bar 4a U-shaped part 4b Linear part 5 Mounting bolt 6 Washer 7 Fixing nut

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Yoshiyuki Oguni 4-53, Kitahama, Chuo-ku, Osaka City, Osaka Prefecture F-term within Sumitomo Metal Industries, Ltd. 2D041 AA02 BA37 CA01 CB05 DB02 DB03 DB05 2D046 CA04

Claims (4)

[Claims] In a structure of a foundation pile head in which a joint reinforcing bar is fixed to a connection fitting attached to an outer periphery of a pile head, the connection fitting having an arc-shaped portion below has an arc shape of the connection fitting. The structure of a foundation pile head characterized in that U-shaped joint reinforcing bars corresponding to the parts are nationally defined. 2. The foundation pile according to claim 1, wherein a groove-like portion in which a joining rebar can be engaged is formed continuously from both sides to the lower end at both sides and a lower end of the connection fitting. Head structure. 3. The structure of the foundation pile head according to claim 1, wherein a reinforcing bar locking portion is continuously formed from both sides to the lower end on both sides and a lower end of the connection fitting. . 4. A reinforcing bar engaging portion is formed on both sides and a lower end portion of the connection fitting so as to be continuous from both sides to a lower end portion, and the reinforcing bar engaging portion is formed to have a substantially L-shaped cross section. The structure of the head of the foundation pile according to claim 2, wherein the inner periphery is formed in a substantially groove shape in cross section continuous with the groove portion.