JP2000352062A - Steel pipe pile-to-foundation concrete junction structure and junction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steel pipe pile-to-foundation concrete junction structure and junction method in which need of welding a strip or the like for preventing deviation is eliminated, in which welding work at site can be omitted to reduce a construction period and construction cost, and in which force in a pile axis direction can be easily and securely transmitted to a foundation concrete structure. SOLUTION: A steel pipe pile comprises junction steel pipes 9s of a specified length having plural reinforcement 5 for junction of pile heads along an outer circumference or an inner circumference in a circumferential direction in the outer circumference or the inner circumference of their head parts which are concentrically fitted and disposed, with one or plural knot parts 14a, 14b protruded to a specified height with the junction steel pipe 9s in a fitting range of it. A steel pipe pile-to-foundation concrete junction structure in which a fixed reinforcement range for junction is embedded in a foundation concrete structure and integrally jointed by concrete.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel pipe pile and a foundation concrete applied to the construction of a foundation concrete structure such as a foundation footing structure and a foundation beam structure on a plurality of steel pipe piles driven into the ground. The present invention relates to a joining structure with a structure and a joining method.

[0002]

2. Description of the Related Art Conventionally, in order to construct a civil engineering building structure,
The method of embedding steel pipe piles in the ground by casting method, press-fitting method, rotating method, pre-boring method or Nakabori method, and joining the basic concrete structure such as foundation footing structure on this steel pipe pile is mainly done by the method A and method B.

[0003] In the method A, as shown in FIG.
A plurality of rows of strips 2 are arranged in the axial direction and welded on the inner surface and the outer surface of the head of the steel pipe pile 1 buried in the steel pipe, and the pile head including the slip prevention welded portion is connected to the steel pipe pile. 1 and is arranged so as to be embedded in the basic footing structure 3 over a length L which is equal to or greater than the diameter D. When the basic reinforcing steel 8 for the basic footing is arranged as shown in FIG. This is a method in which the base concrete 4 is filled also in the inside and the steel pipe pile 1 and the base footing structure 3 are joined.
Reference numeral 7 in FIG. 8 denotes an arrangement hole in the head of the steel pipe pile 1.

[0004] In the method B, as shown in FIG. 7, a plurality of strips 2 for preventing slippage are arranged on the inner surface of the head of a steel pipe pile 1 buried in the ground 10 by welding. After arranging the lower region of the pile-shaped reinforcing steel bar 4 formed in an annular shape inside the pile head, the concrete 4 is filled inside the pile head over a length Lh equal to or more than the diameter D of the steel pipe pile. Fix the head and the reinforcing bar 5 for connecting the pile head, and fix the tip of the pile head and the reinforcing bar 5 for connecting the pile head.
Are arranged so as to be embedded in the basic footing structure 3, and a main reinforcing bar 8 for the basic footing is arranged so that
To form the basic footing structure 3 and join the steel pipe pile 1 and the basic footing structure 3. Also,
In method B, when the required bending moment resistance cannot be obtained because the arrangement diameter of the reinforcing bar 5 for pile head connection is small, the reinforcing steel bar 5 for pile head connection is annularly arranged on the outer peripheral surface of the pile head and fixed. In some cases. ｛Reference Technology “Road Bridge Specifications and Explanations”, published by the Japan Road Association in December 1996, pp. 370-375 (Figure-Solution 10.9.6)｝.

In any of the above methods, in order to surely transmit the axial force of the pile to the foundation concrete structure, a strip 2 or the like for preventing the steel pipe pile 1 from slipping is attached to the head of the steel pipe pile. It is necessary to arrange a plurality of stages on one or both of the inner surface and the outer surface and fix them by welding.
In order to prevent the pile from stopping at a high level, it is common to attach a bent strip 2 or the like at the site, and this slip prevention work requires a long time and it is difficult to shorten the construction period. However, since high skill is required, there is a problem that the construction cost burden is large.

[0006]

SUMMARY OF THE INVENTION The present invention eliminates the need for a strip or the like to prevent slippage, reduces the welding work load at the site, reduces the construction period and construction cost, and reduces the axial force of the pile. An object of the present invention is to provide a joining structure and a joining method between a steel pipe pile and a foundation concrete structure, which are easily and surely transmitted to the foundation concrete structure.

[0007]

Means for Solving the Problems The present invention provides the following (1) to
It is constituted by the invention of (2). (1) In a joint structure between a steel pipe pile and a foundation concrete structure, the steel pipe pile is a concentric circular steel pipe having a predetermined length to which a plurality of pile head reinforcing bars are fixed in advance on the outer or inner circumference of the head. One or more nodes with a predetermined projection height are formed in the fitting area together with the jointed steel pipe by fitting and arranging the reinforcing steel area for pile head joining fixed to the jointed steel pipe,
A joint structure between a steel pipe pile and a foundation concrete structure, which is embedded in the foundation concrete structure and integrally joined with concrete. (2) In the joining method between a steel pipe pile and a foundation concrete structure, a joining steel pipe of a predetermined length, in which a plurality of pile head rebars are fixed in advance, to the outer or inner periphery of the head of the steel pipe pile, is concentrically fitted. After the joint arrangement, after inserting a diameter expansion device inside the fitting part and locally expanding the steel pipe pile and the jointed steel pipe simultaneously from the inside and plastically deforming and forming one or more nodes with a predetermined projection height, A method for joining a steel pipe pile and a foundation concrete structure, wherein a concrete reinforcing is fixed by embedding a reinforcing steel for pile head joining fixed to the joint steel pipe in the foundation concrete structure.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the present invention, a joint steel pipe having a reinforcing member for pile head joint fixed to a head region is concentrically arranged and simultaneously expanded in diameter and plastically deformed to form a node having a predetermined height. A steel pipe pile head with structural reinforcement is embedded in a foundation concrete structure such as a foundation footing structure or foundation beam structure (hereinafter referred to as a “foundation concrete structure”) by embedding reinforcing steel for pile head connection into a foundation concrete structure. It is joined together with concrete. Basically, concrete inside the steel pipe pile head (may also be used as basic concrete)
Is filled, and the nodes are cut into the filled concrete and the foundation concrete structure to have a slip preventing function.

According to the present invention, the reinforcing steel for pile head connection can be mass-produced by being fixed to the steel pipe in advance, and the work of connecting the reinforcing steel for pile head bonding on site can be reduced. Since the construction time is short and requires little skill, the construction period can be shortened and the construction cost can be reduced.

Hereinafter, each invention of the present invention will be described.
In the inventions of (1) and (2) of the present invention, an annular reinforcing steel for pile head joining is previously fixed to the outer peripheral surface or inner peripheral surface of the joined steel pipe by welding or the like, and the joined steel pipe is connected to the steel pipe pile. Fit to the outer or inner circumference of the head and simultaneously expand and fix the local diameter,
The steel pipe pile and the foundation concrete structure are firmly and integrally joined by embedding concrete into the foundation concrete structure by embedding an annular reinforcing steel for the pile head bonded to the outer peripheral surface of the jointed steel pipe. The inside of the head is filled with concrete (it may also be used as the foundation concrete), and the reinforcing steel for joining the annular pile head is cut into the filling concrete and the foundation concrete structure to provide a slip prevention function. .

The joint structure between a steel pipe pile and a foundation concrete structure according to the present invention can be constructed, for example, by the following procedure. a. Casting (burying) steel pipe piles into the ground b. A concentrically fitted steel pipe having a reinforcing steel for pile head bonding fixed in an annular shape on the outer or inner circumference of the steel pipe pile head in advance on the outer or inner circumference c. Insert a diameter expansion device inside the fitting part, and locally expand the diameter of the steel pipe pile head and the joined steel pipe simultaneously from inside to form plastically deformed nodes. D. Arrange the formwork for the foundation concrete structure and arrange the reinforcing bars. E. Pour the foundation concrete into the formwork, fill this foundation concrete into the steel pipe pile head, embed the tip of the steel pipe pile head and the annular pile head reinforcing steel into the foundation concrete, and cure and solidify it. Thereby, the steel pipe pile and the foundation concrete structure are joined.

In the joint structure of the present invention thus constructed, an annular pile head joined to the foundation concrete structure and fixed to the outer peripheral surface of the joint steel pipe firmly fixed to the steel pipe pile at the joint is provided. When the reinforcing bars are firmly fixed and the base concrete is filled into the steel pipe pile heads and digs in. And the structure can be strengthened.

According to the present invention, since the axial force is transmitted to the filled concrete, there is almost no decrease in the axial proof strength as a pile, and a joint structure having a structural performance equal to or higher than that of the conventional method is welded on site. And can be provided. In addition, in the joint structure in which the welded steel pipe is fitted to the inner periphery of the steel pipe pile head, the welded steel pipe is housed inside the steel pipe pile, so there is no step on the outside, so the gap between the welded steel pipe and the steel pipe pile is external. It has good durability because it is not exposed to the environment. In addition, there is a feature that it can be advantageously applied when a step on the outside side hinders construction.

In each of the above-mentioned inventions of the present invention, a joint steel pipe in which a reinforcing steel for joining a pile head is previously fixed to an outer periphery or an inner periphery is concentrically fitted and arranged on a steel pipe pile head. And the jointed steel pipe is locally expanded from the inside and plastically deformed to form a node. This joint can be formed by inserting a diameter expanding device into the steel pipe pile head and locally expanding and plastically deforming the steel pipe pile head and the jointed steel pipe simultaneously from the inside, so the construction time is short and requires much skill. Construction costs are low.

As the shape of the node, in addition to a ring shape having an arc-shaped cross section continuous in the circumferential direction of the steel pipe pile 1, for example, a shape such as a protrusion or a hemisphere discontinuous in the circumferential direction can be used. The height of this node is 10mm to 1 / of the outer diameter of the steel pipe pile.
It is set to about 10 and is formed in the head region of the steel pipe pile in the axial direction in 1 to 3 steps. In addition, the reinforcing steel reinforcing bar (including a strip and a wire rod) is wound around the outer periphery of the annular reinforcing steel bar used in the present invention, and fixed by wire or welding. It is what combines.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. (Embodiment 1) As shown in FIG.
After the steel pipe pile 9 is built into the ground 10 by driving, a joined steel pipe 9 s in which an annular reinforcing steel bar 13 composed of a reinforcing bar 11 and a reinforcing bar 12 is fixed to the outer periphery in advance is connected to a steel pipe pile in a straight pipe state. 9 are fitted concentrically around the outer periphery of the head of the steel pipe pile 9.
The head and the jointed steel pipe 9s are simultaneously locally expanded from the inside and plastically deformed to form two-stage joints 14a and 14b in the axial direction, and the tip of the head of the steel pipe pile 9 and the tip of the joined steel pipe 9s are formed in an annular shape. A range of the length L of the fixing region of the reinforcing steel bar 13 for pile head joining;
3 shows an example of a joint structure in which a foundation footing structure 3 and a foundation concrete 4 are integrated. The reinforcing bars of the basic footing structure 3 are basically arranged in the same manner as in the conventional example shown in FIG. 8, and reference numeral 8 in the figure denotes a basic footing main reinforcing bar.

In this example, a steel pipe pile 9 head fixed by expansion from the inside, a tip end of a joint steel pipe 9s and an annular pile head reinforcing bar 13 are embedded in the formation area of the basic footing structure 3. As shown in FIG.
The reinforcing steel for the basic footing structure as shown in FIG. 1 is laid and the basic concrete 4 is poured, so that the inside of the head region of the steel pipe pile 9 is also filled with the basic concrete 4 so that the steel pipe pile 9 and the foundation are filled. The footing structure 3 is joined, and the reinforcing bar 13 for annular pile head joining is cut into the foundation concrete 4 of the foundation footing structure 3 to have a strong slippage preventing function.

FIG. 2 shows an embodiment 1-2. In this example, as shown in FIG.
After the steel pipe pile 9 is built by casting, a steel pipe 9 s in which an annular reinforcing steel bar 13 composed of a reinforcing steel bar 11 and a reinforcing bar 12 is fixed to the inner periphery in advance, and the head of the steel pipe pile 9 is straightened. Concentrically fitted around the outer periphery, the head of the steel pipe pile 9 and the joint steel pipe 9
s is simultaneously locally expanded from the inside and plastically deformed to form two-stage joints 14a and 14b in the axial direction, for joining the tip of the head of the steel pipe pile 9 and the tip of the joining steel pipe 9s to the annular pile head. Reinforcing bar 1
3 and the range of the length L of the fixing region and the basic footing structure 3
2 shows an example of a joint structure in which the above-mentioned components are integrated with the basic concrete 4. The reinforcing bars of the basic footing structure 3 are basically arranged in the same manner as in the conventional example shown in FIG. 8, and reference numeral 8 in the figure denotes a basic footing main reinforcing bar.

In the first embodiment, the head of the steel pipe pile 9 fixed by expanding the diameter from the inner side, the tip of the jointed steel pipe 9s, and the reinforcing bar 13 for joining the annular pile head are formed in the area where the basic footing structure 3 is formed. By arranging a main reinforcing bar 8 for a foundation footing structure as shown in FIG. 8 in a formwork (not shown) so as to be embedded therein, and placing the foundation concrete 4, the head region of the steel pipe pile 9 is formed. The steel pipe pile 9 and the foundation footing structure 3 are joined by filling the foundation concrete 4 also into the inside of the base, and the reinforcing steel 13 for joining the annular pile head is cut into the foundation concrete 4 of the foundation footing structure 3. , It can have a strong slip prevention function.

(Embodiment 2) In Embodiment 2-1, as shown in FIG. 3, after a steel pipe pile 9 is built into the ground 10 by driving, an annular pile composed of a reinforcing bar 11 and a reinforcing bar 12 is prepared in advance. A joined steel pipe 9 s having a reinforcing steel bar 13 for head joining fixed to the outer periphery is concentrically fitted and arranged on the inner periphery of the head of the steel pipe pile 9 in a straight pipe state, and the joined steel pipe 9 s and the head of the steel pipe pile 9 are placed from inside. At the same time, the joints are locally expanded and plastically deformed to form two-stage nodes 14a and 14b in the axial direction. The example of the joining structure in which the range of the length L of the region and the basic footing structure 3 are integrated with the basic concrete 4 is shown. The reinforcing bars of the basic footing structure 3 are basically arranged in the same manner as in the conventional example shown in FIG. 8, and reference numeral 8 in the figure denotes a basic footing main reinforcing bar.

In this embodiment, a steel pipe pile 9 head fixed by expansion from the inside, a tip end of the joined steel pipe 9s and an annular pile head reinforcing bar 13 are embedded in the formation area of the basic footing structure 3. As shown in FIG. 8, a reinforcing steel for a foundation footing structure is arranged in a formwork (not shown), and the foundation concrete 4 is cast therein.
The steel pipe pile 9 and the foundation footing structure 3 are joined by filling the foundation concrete 4 also into the inside of the head region of the base. 4 can have a strong slip-prevention function.

FIG. 4 shows an embodiment 2-2. In this embodiment, as shown in FIG. 4, after a steel pipe pile 9 is built into a ground 10 by driving, an annular pile composed of a reinforcing bar 11 and a reinforcing bar 12 A joint steel pipe 9 s having a steel bar 13 for head joint fixed to the inner periphery is concentrically fitted and arranged in a straight pipe state, and the head of the steel pipe pile 9 and the joint steel pipe 9 s are simultaneously locally expanded from inside and plastically deformed. The two ends of the joints 14a and 14b are formed in the axial direction, and the range of the length L of the fixing region between the tip of the head of the steel pipe pile 9 and the tip of the joining steel pipe 9s and the reinforcing bar 13 for joining the annular pile head. 2 shows an example of a joint structure in which a foundation footing structure 3 and a foundation concrete 4 are integrated. Reinforcing bars of the basic footing structure 3
Basically, it is performed in the same manner as in the conventional example shown in FIG. 8, and in the figure, reference numeral 8 denotes a basic footing main reinforcing bar.

In this embodiment, a steel pipe pile 9 head fixed by expansion from the inside, a tip end of the joined steel pipe 9s and an annular pile head reinforcing bar 13 are embedded in the formation area of the basic footing structure 3. As shown in FIG. 8, a reinforcing steel for a foundation footing structure is arranged in a formwork (not shown), and the foundation concrete 4 is cast therein.
The steel pipe pile 9 and the foundation footing structure 3 are joined by filling the foundation concrete 4 also into the inside of the head region of the base. 4 can have a strong slip-prevention function. The reinforcing bars of the basic footing structure 3 are basically arranged in the same manner as in the conventional example shown in FIG. 8, and reference numeral 8 in the figure denotes a basic footing main reinforcing bar.

In the above-described first and second embodiments, the diameter expanding apparatus used to form the joints 14a and 14b by locally expanding the head of the steel pipe pile 9 and the joined steel pipe 9s simultaneously from the inside and plastically deforming them. Is a vertical diameter expanding device 15 as shown in FIG.
It is of a type that is suspended by a crane 16, and can be moved up and down by the crane 16, and is equipped with a diameter-enlarging mechanism 18 via a lifting device 17 so that the position can be adjusted in the vertical direction.

More specifically, as shown in FIGS. 5 (b) and 5 (c), the expanding mechanism 18 is provided with hydraulic cylinders 21a to 21e which are radially arranged and operated by a hydraulic device 19 via a hydraulic hose 20. The diameter increasing block 18 is formed at the distal end of a rod 22 which advances and retreats by 21f.
s is inserted into the head of the fitted steel pipe pile 9, and the hydraulic cylinders 21 a to 21 f are simultaneously operated by the hydraulic device 19 via the hydraulic hose 20, and the enlarged diameter block 23 a
By expanding the diameter of 〜23f, a strong expanding force is applied from the inside to the joint steel pipe 9s fitted and arranged on the head of the steel pipe pile 9 and the outer periphery thereof, and the head of the steel pipe pile 9 and the joint steel pipe 9s are applied. Can be simultaneously plastically deformed by locally expanding the diameter. This local diameter expansion region can be adjusted by adjusting the position of the diameter expansion mechanism 18 by the crane 16 and the lifting device 17.

The shapes of the nodes 14a and 14b are determined by the outer shapes of the enlarged blocks 23a to 23f. Here, the shape of the joints 14a and 14b is a ring shape having a circular arc cross-section that is continuous in the circumferential direction, and the joints are formed in two steps one by one in the pile axis direction of the steel pipe pile 9 head. And
In the case of forming three stages in the pile axis direction, for example,
Then, the position of the diameter expanding mechanism 18 may be changed to perform the diameter expanding operation three times. By selecting the outer shape of the enlarged diameter blocks 23a to 23f, two blocks can be formed simultaneously in the pile axis direction.

In the first and second embodiments, in order to omit the on-site welding operation, an annular pile joining reinforcing bar 23 fixed to the outer peripheral surface or inner periphery of the joined steel pipe 9s is provided at the joint 1
It is fixed to the joined steel pipe 9s before forming the 4a, 14b, but it may be fixed after the steel pipe pile 9 head and the joined steel pipe 9s are simultaneously expanded in diameter.

The present invention is not limited to the above embodiment. For example, for the steel pipe piles used, the structural conditions (including the joint formation conditions) of the joined steel pipes, the structural conditions of the expanding device, the building conditions, the reinforcing bar conditions for pile head connection, the construction procedure, etc. Concrete structure conditions, load conditions,
It is changed within a range satisfying the claims according to a required supporting pressure condition or the like.

[0029]

According to the present invention, the joint steel pipe is concentrically fitted to the head of the steel pipe pile, and at the same time, the outer diameter of the joint pipe is expanded to form a node, and the outer peripheral surface of the joint steel pipe and / or An annular pile head reinforcing steel is fixed inside the steel pipe pile, and the steel pipe pile integrated with the steel pipe and the annular pile head reinforcing steel are buried in the foundation concrete structure. The concrete structure is firmly joined, and the ring-shaped pile head joint reinforcement is used to firmly prevent slippage,
We can easily and reliably transmit the axial force of piles to the foundation concrete structure while reducing the work load on the site, such as a strip for preventing slippage, reducing the construction period and construction cost. .

[Brief description of the drawings]

FIG. 1 (a) is a partially cutaway side sectional explanatory view showing an example of a joint structure between a steel pipe pile and a foundation footing structure in Example 1-1 of the present invention, and FIG. 1 (b) is a diagram (a). Aa-A in the figure
FIG.

FIG. 2 (a) is a partially cutaway side sectional view showing an example of a joint structure between a steel pipe pile and a foundation footing structure in Example 1-2 of the present invention, and FIG. 2 (b) is a diagram (a). Aa-Ab arrow plane explanatory view of FIG.

FIG. 3 (a) is a partially cutaway cross-sectional explanatory view showing an example of a joint structure between a steel pipe pile and a foundation concrete structure in Example 2-1 of the present invention, and FIG. 3 (b) is a diagram (a). Aa-Ab
FIG.

FIG. 4 (a) is a partially cutaway side sectional view showing an example of a joint structure between a steel pipe pile and a foundation concrete structure in Example 2-2 of the present invention, and FIG. 4 (b) is a diagram (a). Aa-Ab
FIG.

5A is an explanatory side view showing a structural example of a diameter expanding device used in the present invention, and FIG. 5B is a partially cutaway side view showing an exemplary structure of a diameter expanding mechanism in FIG. FIG. 3C is a cross-sectional plan view taken along the line Aa-Ab in FIG.

FIG. 6 is an explanatory side sectional view showing an example of a joint structure between a conventional steel pipe pile and a foundation footing structure.

FIG. 7 is an explanatory side sectional view showing another example of a joint structure between a conventional steel pipe pile and a foundation footing structure.

FIG. 8 is an explanatory plan view showing an example of arrangement of reinforcing bars in a conventional steel pipe pile and a foundation footing structure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Steel pipe pile 2 Strip plate 3 Foundation footing structure 4 Foundation concrete 5 Pile head joint reinforcement 6 Reinforcing bar 7 Arrangement hole of steel pipe pile 8 Foundation footing main reinforcement 9 Steel pipe pile 9 s Joined steel pipe 10 Ground 11 Reinforcement 12 Reinforcement 13 Pile head Reinforcing bars 14a, 14b Knot 15 Diameter expanding device 16 Crane 17 Lifting device 18 Diameter expanding mechanism 19 Hydraulic device 20 Hydraulic hose 21a-21f
Hydraulic cylinder 22 Rod 23a-23f
Expanding block

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shigeki Terasaki 2-6-3 Otemachi, Chiyoda-ku, Tokyo F-term in Nippon Steel Corporation (reference) 2D041 AA02 BA37 DB02 2D046 CA04

Claims (2)

[Claims] In a joint structure between a steel pipe pile and a foundation concrete structure, a steel pipe pile has a joint steel pipe having a predetermined length to which a plurality of reinforcing bars for pile head joints are fixed in advance on an outer periphery or an inner periphery of a head thereof. One or more joints with a predetermined protrusion height are formed in the fitting area together with the joint steel pipe by fitting and arranging concentrically, and the reinforcing steel area for pile head joining fixed to the joint steel pipe is used as the foundation concrete. A joint structure between a steel pipe pile and a foundation concrete structure, which is embedded in the structure and integrally joined with concrete. 2. A method for joining a steel pipe pile and a foundation concrete structure, wherein a joint steel pipe of a predetermined length, in which a plurality of pile head reinforcing bars are fixed in advance, on the outer circumference or inner circumference of the head of the steel pipe pile, is formed concentrically. After the fitting arrangement, after inserting the diameter expansion device inside the fitting part and locally expanding the steel pipe pile and the jointed steel pipe simultaneously from the inside to plastically deform and form one or more nodes with a predetermined projection height A method of joining a steel pipe pile to a foundation concrete structure, wherein a concrete for reinforcing the pile head jointed to the jointed steel pipe is buried in the foundation concrete structure and cast concrete.