JPH11172670A - Steel pipe, steel pipe pile and preparation method of steel pipe pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steel pipe, a steel pipe pile and the preparation method of the steel pipe pile, by which a reinforcing bar is not deformed and ruptured and footing size is not increased. SOLUTION: In a pile head 20, reinforcement fixing holes 21 are formed to one end face (an upper end face under the state, in which the pile head is installed into a ground) through required intervals in the peripheral direction. Female screws 21a are cut to the inner circumferential surfaces of the reinforcement fixing holes 21. The central axes of the reinforcement fixing holes 21 are conformed to the center of the plate thickness of a drum section 10. The plate thickness of an upper section is increased to the inside and outside in the radial direction. The lower section is tapered so that plate thickness is augmented gradually towards the upper section. The plate-thickness increasing section 22 of the pile head 20 reaches the treble or more of the plate thickness of the drum section 10, and the length of the wall-thickness section 22 of the pile head 20 reaches the quadruple or more of the plate thickness of the drum section 10. A lower end is welded and fixed at the drum section 10 (a general steel pipe 1) from the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel pipe, a steel pipe pile, and a method for forming a steel pipe pile which are particularly suitable for a cast-in-place steel pipe concrete pile.

[0002]

2. Description of the Related Art Conventionally, when a footing of reinforced concrete and a foundation slab are constructed on a pile head of a cast-in-place steel pipe concrete pile, after constructing a cast-in-place steel pipe concrete pile, the excess concrete (defective concrete portion) of the pile head is formed. After removal, weld the lower ends of many rebars to the steel pipe at the pile head and connect them, assemble the pile head and the formwork connected to the outer periphery of this head and surrounding the standing rebar, and formwork Cast concrete inside.

As a method of welding and joining the lower ends of a large number of rebars to a steel pipe at the head of a pile, a method of welding and rebar R to the outer peripheral surface of a steel pipe S is generally used as shown in FIG. ing.

Further, as shown in FIG. 18, a method of welding a ring plate 100 to an upper end surface of a steel pipe S in advance and welding a reinforcing bar R to the ring plate 100 (the invention described in Japanese Patent Application Laid-Open No. Hei 9-71948) is also available. Provided.

[0005] Further, since it is difficult to weld the lower end of the reinforcing steel R to the pile head, in the cast-in-place steel pipe concrete pile, the outer surface of the steel pipe S or the steel pipe S is required.
19 or 20, a hollow coupler 200 for connecting the reinforcing bar R is welded to the outer surface of the steel pipe S as shown in FIGS. Have been.

In a general steel pipe pile, Japanese Patent Laid-Open No.
A pile (steel pipe S) with a reinforcing bar connector 300 as shown in JP-A-53418 is provided (FIGS. 21 and 2).
2).

[0007]

However, the prior art has the following problems.

[0008] In the cast-in-place steel pipe concrete pile, the reinforcing steel R used for the pile head joint is previously set on the outer periphery of the steel pipe S (Fig. 17),
In the case where the steel pipe S is welded to the upper end face via the ring plate 100 and installed (FIG. 18), when the excess concrete in the pile head concrete portion is removed, the reinforcing steel R is largely deformed, and sometimes the reinforcing steel R is broken. There was a case.

When a hollow coupler 200 is welded to the outer periphery of a steel pipe with a cast-in-place steel pipe concrete pile (FIG. 1).
9, FIG. 20) and a pile with a reinforcing bar connector 300 as shown in JP-A-62-153418 (FIG. 2).
1, (FIG. 22), the diameter of the reinforcing bar R was increased, and the footing dimension surrounding the reinforcing bar had to be increased.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a steel pipe, a steel pipe pile, and a steel pipe pile which do not deform or break a reinforcing bar and do not increase a footing dimension. The point is to provide a method for constructing.

[0011]

The gist of the present invention is to provide a steel pipe pile fixed to the ground by a plastic hardening material and used as a pile by fixing a reinforcing bar to an upper end surface exposed above the ground. The steel pipe according to claim 1, wherein a reinforcing bar fixing hole is provided at an end portion which becomes a pile head in a built state. The gist of the invention according to claim 2 resides in the steel pipe according to claim 1, wherein an end portion serving as a pile head is thickened in a built-in state to form a thickened portion. The gist of the invention according to claim 3 resides in the steel pipe according to claim 1 or 2, wherein a female screw is formed on an inner surface of the reinforcing bar fixing hole. The gist of the invention according to claim 4 resides in the steel pipe according to claim 1, wherein the central axis of the reinforcing-bar fixing hole is within the thickness of the body. The gist of the invention described in claim 5 is that
Or a steel pipe pile formed in the ground, comprising the steel pipe according to any one of (4) and (4). The gist of the invention according to claim 6 is a method for forming a steel pipe pile used as a pile by fixing a steel pipe in the ground and fixing a reinforcing bar to an upper end surface of the steel pipe, wherein the steel pipe is inserted into a hole in the ground. A step of erection, a step of casting a plastic hardening material into the hole, a step of removing a defective portion of the plastic hardening material adhered to the steel pipe, and a fixing of a reinforcing steel bar formed on an upper end face of a pile head of the steel pipe. A method for forming a steel pipe pile, comprising a step of removing a cover closing a hole before casting the plastic hardening material, and a step of fixing a reinforcing bar in the reinforcing bar fixing hole. .

In the present invention, “plastically hardened material” means
A hardened material suitable for practicing the present invention, such as concrete and mortar.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. The steel pipe according to the present embodiment is used for forming a cast-in-place steel pipe concrete pile. As shown in FIG. 1, the steel pipe 1 includes a body 10,
And a pile head 20 provided at one end of the body 10.

The body 10 is a general round steel pipe having an annular cross section.

As shown in FIG. 2, the pile head 20 has a reinforcing bar fixing hole 21 at one end surface (the upper end surface in a state where the pile head is installed in the ground) at a required interval in the circumferential direction.
As shown in FIG. 3, a female screw 21 a is cut on the inner peripheral surface of the reinforcing bar fixing hole 21. The central axis of the reinforcing bar fixing hole 21 coincides with the center of the thickness of the body 10. The thickness of the upper plate is increased inward and outward in the radial direction. The lower part is tapered so that the plate thickness gradually increases as going upward. The thickened portion 22 of the pile head 20 is at least three times the plate thickness of the trunk 10, and the length of the thickened portion 22 of the pile head 20 is at least four times the plate thickness of the trunk 10. Lower end at trunk 10 (general steel pipe 1)
Is fixed to the upper end by welding from the outside.

Next, a method of forming a cast-in-place steel pipe concrete pile using the steel pipe 1 will be described below with reference to FIGS.

First, as shown in FIG. 8 and FIG.
While digging, a casing (not shown) is built.

Next, the steel pipe 1 according to the present embodiment and the steel cage 4 (shown in FIG. 10) are connected on the ground G. At this time, as shown in FIGS. 4 and 5, the reinforcing rod fixing hole 21 is covered with a bolt 3 (lid) to prevent the ready concrete from entering the reinforcing rod fixing hole 21. The circle in FIG.
The enlarged part of is shown. The connection between the steel pipe 1 and the reinforcing bar 4 can be made in a factory, a site yard, etc., before excavation and installation of a casing.

Next, as shown in FIG. 10, the steel pipe 1 and the reinforcing bar 4 which are connected to each other are inserted into the drilled holes.

Next, as shown in FIG. 11, a tremy tube T is inserted into the reinforcing bar 4.

Next, as shown in FIG. 12, ready-mixed concrete L (plastically hardened material) is poured.

Next, the casing is pulled out, and after the concrete is hardened, as shown by a dotted line in FIG.
Drilling.

Next, as shown by the dotted line in FIG. 14, the excess concrete Z on the upper part of the pile head is removed.

Next, the bolts 3 serving as the lids of the reinforcing bar fixing holes 21 shown in FIGS. 4 and 5 are removed, and as shown in FIG. Screw. 6 and 7 show a state in which the screw reinforcing bar 2 is screwed. The circle in FIG. 6 shows an enlarged portion of FIG.

Through the above steps, the cast-in-place steel pipe concrete pile P can be formed. After that, as shown in FIG. 16, the footing formwork is installed, and then the footing F, the foundation beam, the column C, and the like are formed as in the normal process.

Since the steel pipe 1 according to the embodiment is configured as described above, the following effects can be obtained. further,
Since a hollow connection portion is used for the bolt 3, there is a possibility that concrete is clogged in the hollow portion. In addition, at the time of concrete casting, if the bolt 3 is screwed only from above the reinforcing hole, concrete infiltration can be prevented, so that the screw hole can be easily protected.

After the excess concrete is removed as described above, the reinforcing steel can be fixed to the upper surface of the pile head 20.
Deformation and breakage of the rebar can be prevented.

Further, since a coupler, a rebar connection tool or the like is not required, the footing size can be reduced.

Further, since the reinforcing rod R and the axis of the plate thickness of the steel pipe 1 coincide with each other, no additional moment is applied to the reinforcing rod R, and a decrease in the tensile strength of the reinforcing rod R can be prevented. .

Further, since the screw rebar 2 can be fixed only by screwing the screw rebar 2 into the rebar fixing hole 21, the welding can be performed without welding. Work labor can be reduced, work time can be reduced, and construction costs can be reduced.

In this embodiment, the present invention is applied to a cast-in-place steel pipe concrete pile. However, the present invention is not limited to this. For example, the present invention is applied to an ordinary steel pipe pile or the like suitable for carrying out the present invention. be able to.

Further, as one form of application to a cast-in-place steel pipe concrete pile, it becomes easy to attach a seismic isolation bearing using a screw hole of a pile head.

The present invention can also be applied to steel pipe sheet piles.

The steel pipe is not limited to a circular steel pipe, and a steel pipe having a cross section suitable for carrying out the present invention, such as a square steel pipe, can be used.

In the above embodiment, the body 10
The thick pile head 20 is welded and fixed to the (general steel pipe 1). For example, in the present invention, the pile head 20 is manufactured integrally using a thick steel plate, or a flange is formed at the upper end of the trunk and the lower end of the pile head. It can be made by bolting or by a method suitable for carrying out the present invention.

Further, as a method of producing the thickened portion, for example, the thickened portion of the end steel tube can be formed by upsetting the end portion of the general steel pipe or by centrifugal casting.

Further, in the above embodiment, the pile head was struck in the pipe radial direction and the wall thickness was increased outward. However, the present invention is not limited to this. You can also increase the meat.

It is also possible to provide a through hole in the pile head in a direction perpendicular to the pipe axis, and to arrange the lower reinforcement of the foundation beam or footing using this through hole.

The welding surface is not limited to the outer surface and the inner surface of the steel pipe.

The number, position, shape, and the like of the reinforcing hole are not limited to the above-described embodiment, but can be set to a number, position, shape, and the like suitable for carrying out the present invention.

If the extension of the central axis of the reinforcing-bar fixing hole is within the thickness of the body, the same effect as in the above embodiment can be obtained.

When a part of the reinforcing-bar fixing hole 21 is open on the side surface of the steel pipe, bolts may be installed in advance to the reinforcing-bar insertion range.

In the drawings, the same components are denoted by the same reference numerals.

[0044]

Since the present invention is configured as described above, it has the following effects. After the excess concrete is removed, the reinforcing bar can be fixed to the upper surface of the pile head, so that deformation and breakage of the reinforcing bar can be prevented. Also,
Since couplers and rebar connectors etc. according to the prior art are unnecessary,
The footing size can be reduced.

[Brief description of the drawings]

FIG. 1 is a side view of a steel pipe according to an embodiment of the present invention.

FIG. 2 is a plan view of the steel pipe shown in FIG.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a side view of a pile head of a steel pipe pile with a bolt covered.

FIG. 5 is an enlarged vertical sectional view of a portion surrounded by a circle in FIG. 4;

FIG. 6 is a side view of a pile head of a steel pipe pile in a state where a screw reinforcement is screwed into a reinforcement hole.

FIG. 7 is an enlarged vertical sectional view of a portion surrounded by a circle in FIG. 6;

8 is a process chart of pile formation using the steel pipe shown in FIG.

FIG. 9 is a process chart of pile formation using the steel pipe shown in FIG. 1;

FIG. 10 is a process diagram of pile formation using the steel pipe shown in FIG.

FIG. 11 is a process chart of pile formation using the steel pipe shown in FIG. 1;

FIG. 12 is a process chart of pile formation using the steel pipe shown in FIG. 1;

13 is a process chart of pile formation using the steel pipe shown in FIG.

14 is a process chart of pile formation using the steel pipe shown in FIG.

FIG. 15 is a process chart of pile formation using the steel pipe shown in FIG. 1;

FIG. 16 is a process chart of pile formation using the steel pipe shown in FIG. 1;

FIG. 17 is a longitudinal sectional view showing a conventional technique.

FIG. 18 is a perspective view showing a conventional technique.

FIG. 19 is a partially broken plan view showing a conventional technique.

FIG. 20 is a longitudinal sectional view showing a conventional technique.

FIG. 21 is a plan view showing a conventional technique.

FIG. 22 is a longitudinal sectional view showing a conventional technique.

[Explanation of symbols]

 G Ground G 'Surface ground R Reinforcement S Steel pipe P Steel pipe concrete pile T Tremy pipe L Fresh concrete (plastically hardened material) Z Extra concrete F Footing C Column 1 Steel pipe 2 Screw reinforcing rod 3 Bolt 4 Reinforcing cage 10 Body 20 Pile head 21 Reinforcing bar fixing hole 21a Female screw 22 Thickening part 100 Ring plate 200 Coupler 300 Reinforcing bar fitting

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Haruo Uemura 4-6 Kojimacho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture

Claims (6)

[Claims] 1. A steel pipe for a steel pipe pile fixed in a ground by a plastic hardening material and used as a pile body by fixing a reinforcing bar to an upper end surface exposed above the ground, wherein the pile head is installed in a piled state. A steel pipe characterized by having a reinforcing bar fixing hole at an end portion. 2. The thickened portion is formed by increasing the thickness of the end serving as the pile head in the built-in state.
The described steel pipe. 3. The steel pipe according to claim 1, wherein a female screw is formed on an inner surface of the reinforcing bar fixing hole. 4. The steel pipe according to claim 1, wherein the central axis of the reinforcing-bar fixing hole is within the thickness of the body. 5. A steel pipe pile formed in the ground, comprising the steel pipe according to claim 1, 2, 3, or 4. 6. A method of forming a steel pipe pile used as a pile body by fixing a steel pipe in a ground and fixing a reinforcing bar to an upper end surface of the steel pipe, wherein a steel pipe is erected in a hole in the ground. Casting a plastic hardening material into the hole, removing a defective portion of the plastic hardening material adhered to the steel pipe, and rebar fixing holes machined on an upper end surface of a pile head of the steel pipe, A method for forming a steel pipe pile, comprising: a step of removing a closed lid before casting a hardening material; and a step of fixing a reinforcing bar in the reinforcing bar fixing hole.