JP2018172868A - Pile head fixing and holding structure of reinforcing bar cage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pile head fixing and holding structure of a reinforcing bar cage capable of constructing a place casting pile with high working efficiency.SOLUTION: A pile head fixing and holding structure 100 of a reinforcing bar cage can be easily assembled by fixing an upper end portion 11 of a flexible reinforcing bar 10 corresponding to the upper end of a reinforcing bar cage 30 to the inner circumferential surface of a mouth pipe 50 previously set in an upper opening of a pile hole. The mouth pipe 50 used for this pile head fixing and holding structure 100 has previously installed in the upper opening of the pile hole because it was used to form a pile hole by drilling the ground, is also buried with concrete together with the reinforcing bar cage 30 built in the pile hole, and is not a temporary facility to be installed to hold the reinforcing bar cage 30 built in the pile hole or to remove it after use. Therefore, by utilizing the pile head fixing and holding structure 100 of the reinforcing bar cage, it is possible to construct a place casting pile with high working efficiency.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a pile head fixing and holding structure of reinforcing bar for constructing a cast-in-place pile, and relates to a pile head fixing and holding structure of reinforcing bar using a flexible reinforcing bar.

  Conventionally, the upper part of the pile hole is used to hold the reinforcement bar built in the pile hole until the concrete is placed in the pile hole after the reinforcement bar used for the cast-in-place pile is built in the pile hole. A fixed mount such as Kanzashi steel is temporarily installed in the opening, and the upper end of the reinforcing bar is fixed to the fixed mount (see, for example, Patent Document 1).

JP 11-36293 A

However, after the cast-in-place pile is constructed by placing concrete in the pile hole, the fixed mounts such as Kanzashi steel materials will be removed. It may be regarded as a problem if it is a loss. That is, there is a problem that due to the work time, the construction period and construction cost increase, leading to an increase in construction cost.
As a result of intensive studies on a method for holding a reinforcing bar rod built in a pile hole without using a temporary facility, the present inventors have found a technique capable of constructing a cast-in-place pile efficiently. It was.

  An object of the present invention is to provide a pile head fixing and holding structure of a reinforcing bar rod capable of constructing a cast-in-place pile efficiently.

In order to achieve the above object, the present invention provides:
Reinforcing bar that holds a reinforcing bar rod having a plurality of flexible reinforcing bars arranged at appropriate intervals in the circumferential direction and one or a plurality of band reinforcing bars wound around the plurality of flexible reinforcing bars in a state where it is built in a pile hole A pile head anchoring retention structure
Among the plurality of flexible rebars, at least one flexible rebar protruding upward on the upper end side of the rebar rod is an inner peripheral surface of a substantially cylindrical mouth tube that is installed in advance in the upper opening of the pile hole. To be fixed to.

The pile head fixing and holding structure of the reinforcing bar with such a configuration is achieved by fixing the flexible reinforcing bar protruding upward on the upper end side of the reinforcing bar to the inner peripheral surface of the mouth pipe previously installed in the upper opening of the pile hole. Easy to assemble.
Since the flexible reinforcing bar has flexibility, even when the reinforcing bar rod and the mouth tube are separated from each other, the flexible reinforcing bar can be bent and fixed to the mouth tube.
In other words, if you want to use the mouth pipe pre-installed in the pile hole to hold the rebar built in the pile hole, install or remove temporary equipment such as Kanzashi steel As a result, it is possible to construct a cast-in-place pile efficiently. Moreover, if the loss of work time can be eliminated, the construction cost of cast-in-place piles can be reduced by shortening the construction period and reducing the construction cost.
The mouth tube may be a liner plate.

Also, preferably
The flexible reinforcing bar is fixed to the inner peripheral surface of the mouth tube, and the flexible reinforcing bar is fixed in a state where the upper end side of the reinforcing bar rod is expanded.
If the flexible rebar is fixed to the inner peripheral surface of the mouth tube with the upper end side of the rebar bar expanded, it will be easier to secure a wide area on the center side of the mouth tube at the upper end surface of the cast-in-place pile. This increases the degree of freedom in designing structures such as pillars that are constructed so as to be connected to the upper end of the pile.
In particular, if all the flexible reinforcing bars are fixed in a state where the upper end side of the reinforcing bar is expanded, it is possible to secure a wider area on the upper end surface of the cast-in-place pile, so that it is connected to the upper end surface of the cast-in-place pile. This increases the degree of freedom in designing structures such as pillars.

Also, preferably
The flexible reinforcing bars fixed in an expanded state on the inner peripheral surface of the mouth tube are provided with an annular reinforcing bar so as to be inscribed in the reinforcing bar rod.
When the flexible reinforcing bar is curved so as to expand the upper end of the reinforcing bar rod, abdominal pressure acts on the reinforcing bar rod. For the abdominal pressure where the outer periphery of the reinforcing bar rod is compressed, the straps arranged on the outer peripheral side of the reinforcing rod rod function as reinforcing bars. By disposing an annular reinforcing bar having a diameter so as to be inscribed, it becomes possible to resist an abdominal pressure at which the inner peripheral side of the reinforcing bar rod is compressed.

Also, preferably
The inner peripheral surface of the mouth tube is provided with a reinforcing bar fixing portion to which the flexible reinforcing bar is fixed,
A small hole or slit into which the upper end of the flexible reinforcing bar is inserted is formed in the reinforcing bar fixing part,
A fixing tool larger than the diameter of the small hole or the width of the slit is attached to a position above the reinforcing bar fixing portion of the flexible reinforcing bar inserted into the small hole or the slit. .
By doing this, the upper end of the flexible reinforcing bar on the upper end side of the reinforcing bar is locked to the reinforcing bar fixing part provided on the inner peripheral surface of the mouth tube. It can hold suitably.

  ADVANTAGE OF THE INVENTION According to this invention, the pile head fixation holding | maintenance structure of a reinforcing bar rod which can construct a cast-in-place pile efficiently is obtained.

It is the schematic of the reinforcing bar rod of Embodiment 1, and shows the reinforcing rod rod (a) seen from the side and the reinforcing rod rod (b) seen from the top. They are the perspective view (a) which shows the mouth pipe utilized for the pile head fixation holding structure of a reinforcing bar, and the perspective view (b) which shows the pile head fixation holding structure of the reinforcing bar of this embodiment. It is explanatory drawing (a) (b) which shows the process of assembling the pile head fixation holding | maintenance structure of a reinforcing bar rod by the building-in procedure of the reinforcing rod rod of Embodiment 2. FIG. It is explanatory drawing (c) (d) which shows the process of assembling the pile head fixation holding | maintenance structure of a reinforcing bar rod by the construction procedure of the reinforcing rod rod of Embodiment 2. FIG. It is explanatory drawing which shows a partial cross section view of the modification of the pile head fixing holding structure of the reinforcing bar. It is a perspective view which shows the modification of a mouth pipe used for the pile head fixation holding structure of a reinforcing bar. The top view (a) which shows the modification of a mouth pipe, the top view (b) which shows the pile head fixation holding structure of a reinforcing bar using the mouth pipe, and expands a part of the pile head fixation holding structure It is a perspective view (c) shown. It is the schematic of the reinforcing bar clerk of Embodiment 2, the state (a) which extended the reinforcing bar bar, the reinforcing bar bar in the top view (b), the state in the middle of extension or contraction of the reinforcing bar bar (c), and the reinforcing bar The state (d) which contracted the eyelid is shown. It is explanatory drawing (a) (b) (c) which shows the process of assembling the pile head fixation holding | maintenance structure of a reinforcing steel rod by the reinforcement rod construction procedure of Embodiment 1. FIG. It is explanatory drawing (d) (e) which shows the process of assembling the pile head fixation holding | maintenance holding structure of a reinforcing bar rod by the building-in procedure of the reinforcing rod rod of Embodiment 1. FIG.

  Hereinafter, with reference to drawings, an embodiment of a pile head fixing holding structure of a reinforcing bar rod according to the present invention will be described in detail. However, the embodiments described below are given various technically preferable limitations for carrying out the present invention, but the scope of the present invention is not limited to the following embodiments and illustrated examples.

(Embodiment 1)
As shown in FIGS. 1A and 1B, the reinforcing bar rod 30 according to the first embodiment is wound around a plurality of flexible reinforcing bars 10 arranged at appropriate intervals in the circumferential direction and the plurality of flexible reinforcing bars 10. And a spiral band 20.

The flexible rebar 10 is a rebar having flexibility, which is also referred to as a strand rebar, for example, a rebar made of a material that does not cause a problem in strength even when bent to the same degree of curvature as the band rebar 20. For this flexible rebar 10, for example, a material obtained by twisting materials such as carbon fiber, glass fiber, and aramid fiber in addition to a stranded wire and a wire rope can be used.
As shown in FIG. 1, the band 20 is obtained by winding a reinforcing bar around a plurality of flexible reinforcing bars 10 in a spiral shape.

After such a reinforcing bar 30 is built in the pile hole H, until the concrete is placed in the pile hole H, a structure for holding the reinforcing bar 30 in a state of being built in the pile hole H is as follows. It is the pile head fixing holding structure 100 of a reinforcing bar.
The pile head fixing and holding structure 100 of the reinforcing bar rod of the present embodiment uses a substantially cylindrical mouth pipe 50 that is installed in the upper opening of the pile hole H in advance.
The mouth tube 50 is a steel cylindrical member used when the mouth of the ground to be drilled easily collapses. The mouth tube 50 has not only a function of preventing the ground from collapsing, but also a function as a guide when the drill bit enters the ground.

As shown in FIG. 2A, the mouth tube 50 includes a mouth tube body 51 and a reinforcing bar fixing portion 52 provided on the inner peripheral surface of the mouth tube body 51 (mouth tube 50).
The reinforcing bar fixing portion 52 is an annular flat plate member fixed to the inner peripheral surface of the mouth tube body 51 by welding or the like, and has a small hole 52a into which the flexible reinforcing bar 10 is inserted.
In addition, since the reinforcing bar 30 of the present embodiment includes the eight flexible reinforcing bars 10, eight small holes 52 a are formed in the reinforcing bar fixing portion 52 of the mouth tube 50.

As shown in FIG. 2 (b), the upper end portion 11 of the flexible reinforcing bar 10 projecting upward on the upper end side of the reinforcing bar rod 30 is the inner end of the mouth tube 50. It is fixed to the reinforcing bar fixing part 52 of the mouth tube 50 so as to be fixed to the peripheral surface.
Specifically, a tip metal fitting 11 a in which a male screw is formed is fixed to the upper end portion 11 of the flexible rebar 10, and the tip metal fitting 11 a is inserted into the small hole 52 a from the lower side of the reinforcing bar fixing portion 52. The upper end 11 of the flexible rebar 10 is inserted into the mouth tube 50 by screwing a fixture 11b such as a nut larger than the diameter of the small hole 52a into the tip fitting 11a protruding upward from the small hole 52a. It is designed to be fixed to the peripheral surface.
In particular, the eight flexible reinforcing bars 10 fixed to the inner peripheral surface of the mouth tube 50 are fixed in a state where the upper end side of the reinforcing bar rod 30 is expanded.

  Next, the procedure for building the reinforcing bar rod 30 into the pile hole H will be described, and the pile head anchoring holding structure 100 for the reinforcing rod rod that holds the reinforcing bar rod 30 in the pile hole H will be described.

In the cast-in-place pile construction site, as shown in FIG. 3A, a pile hole H is formed by excavating a place where the cast-in-place pile is created, and a mouth pipe 50 is formed in the upper opening of the pile hole H. Is installed.
In addition, a strap winding base 5 provided with a strap winding device 4 is installed immediately above the pile hole H, and a built-up stand 7 provided with a lowering device 6 such as a hanging wire drum is installed on the top. Has been.
Further, around the pile hole H, a drum device 8 around which the flexible rebar 10 is wound is installed. A flexible rebar 10 having a length corresponding to at least the depth of the pile hole H (that is, the design length of the cast-in-place pile) is wound around the drum device 8 in advance.
In addition, when assembling and constructing the reinforcing bar rod 100 in which the eight flexible reinforcing bars 10 are arranged along the longitudinal direction, eight drum apparatuses 8 are installed.

And as shown to Fig.3 (a), the annular | circular shaped lower flame | frame 13 is attached to the edge part of the flexible reinforcement 10 extended | fed out from each drum apparatus 8. As shown in FIG. The lower frame 13 is a known member used for arranging a plurality of flexible rebars 10 at predetermined intervals in the circumferential direction and securing the shape of the reinforcing bar rod.
The lower frame 13 is connected to the wire of the lowering device 6.

Next, as shown in FIG. 3 (b), the flexible rebar 10 is fed out from each drum device 8, and the flexible rebar 10 is fed into the pile hole H together with the lower frame 13.
Further, while feeding the flexible reinforcing bar 10 into the pile hole H, the band 20 is wound around the plurality of flexible reinforcing bars 10 fed into the pile hole H by the band winding device 4 in a spiral shape.
At this time, the lower frame 13 is lowered toward the bottom of the pile hole H by the lowering device 6. In the process of feeding the flexible reinforcing bar 10 into the pile hole H, a known intermediate frame for arranging a plurality of flexible reinforcing bars 10 at predetermined intervals in the circumferential direction is appropriately attached, and the inner space of the reinforcing bar is secured by the annular intermediate frame. You may make it do.

And as shown in FIG.4 (c), if the lower end part of the reinforcing bar rod 30 reaches the vicinity of the bottom face of the pile hole H and forms the reinforcing bar rod 30 of the designed length, the reinforcement rod 30 is substantially built. finish.
In the present embodiment, when the lower end of the reinforcing bar 30 reaches the vicinity of the bottom surface of the pile hole H, the band 20 is wound up to a position slightly below the reinforcing bar fixing part 52 of the mouth tube 50. Further, when the lower end of the reinforcing bar 100 reaches the vicinity of the bottom surface of the pile hole H, the annular upper frame 14 is attached to the flexible reinforcing bar 10 at a position slightly lower than the reinforcing bar fixing part 52 of the mouth tube 50. Keep it.

Next, the end fitting 11 a is fixed to the upper end portion 11 of the flexible reinforcing bar 10 adjusted to a position corresponding to the reinforcing bar fixing portion 52 of the mouth tube 50.
The upper end portion 11 of the flexible reinforcing bar 10 to which the end fitting 11a is fixed is inserted into the small hole 52a of the reinforcing bar fixing portion 52 from the lower side, and the end fitting 11a of the upper end portion 11 protruding above the reinforcing bar fixing portion 52 is inserted. A fixing bracket 11b is attached (see FIG. 2B), and the upper end portion 11 of the flexible rebar 10 is fixed to the inner peripheral surface of the mouth tube 50 as shown in FIG. 4D.
In this way, the pile head fixing holding structure 100 of the reinforcing bar rod is formed by fixing the upper end of the reinforcing bar rod 30 built in the pile hole H to the mouth pipe 50, and the reinforcing rod rod 30 is connected to the pile hole by the pile head fixing holding structure 100. It is made to hold in H and construction of the reinforcing bar 30 is finished.
And the cast-in-place pile can be constructed by removing the built-in rack 7 and placing concrete in the pile hole H in which the reinforcing bar 30 is built and held.

As described above, the pile head fixing and holding structure 100 of the reinforcing bar rod according to the present embodiment is a flexible reinforcing bar corresponding to the upper end of the reinforcing bar rod 30 on the inner peripheral surface of the mouth tube 50 installed in the upper opening of the pile hole H in advance. 10 can be easily assembled by fixing the upper end 11.
In particular, the mouth pipe 50 used for the pile head fixing and holding structure 100 is used for drilling the ground to form the pile hole H, and is therefore installed in the upper opening of the pile hole H in advance. Since it is embedded with concrete together with the reinforcing bar 30 built in the hole H, it is installed in order to hold the reinforcing bar 30 built in the pile hole H or removed after use. Absent.
That is, if the mouth pipe 50 previously installed in the pile hole H is used to hold the reinforcing bar 30 built in the pile hole H, temporary equipment is installed or removed. Since the loss of work time can be saved, cast-in-place piles can be constructed with high work efficiency. Moreover, if the loss of work time can be eliminated, the construction cost of cast-in-place piles can be reduced by shortening the construction period and reducing the construction cost.

  Moreover, if the flexible rebar 10 is fixed to the inner peripheral surface of the mouth tube 50 in a state where the upper end side of the rebar bar 30 is expanded, a wide area is secured on the center side of the mouth tube 50 on the upper surface of the cast-in-place pile. Therefore, there is an advantage that the degree of freedom of design of a structure such as a pillar constructed so as to be connected to the upper end surface of the cast-in-place pile is increased.

Thus, the pile head fixing holding structure 100 of the reinforcing bar of this embodiment is an effective technique for constructing a cast-in-place pile efficiently.
Moreover, according to the pile head fixing holding structure 100 of the reinforcing bar rod of the present embodiment, the construction cost of the cast-in-place pile can be reduced by shortening the construction period and reducing the construction cost.

The present invention is not limited to the above embodiment.
For example, as shown in FIG. 5, an annular reinforcing bar 40 that is inscribed in the reinforcing bar rod 30 is provided on the flexible reinforcing bar 10 that is fixed in an expanded state on the inner peripheral surface (reinforcing bar fixing portion 52) of the mouth tube 50. It is preferable that it is disposed.
When the flexible reinforcing bar 10 is curved so as to expand the upper end of the reinforcing bar rod 30, abdominal pressure acts on the reinforcing bar rod 30.
For the abdominal pressure in which the outer peripheral side of the reinforcing bar 30 is compressed, the strap 20 functions as a reinforcing bar, and therefore, on the inner peripheral side of the reinforcing bar 30, for example, an annular reinforcing bar 40 having a larger diameter than the strap 20. It becomes possible to resist the abdominal pressure which the inner peripheral side of the reinforcing bar rod 30 becomes compression.

Further, as shown in FIG. 6, a plurality of reinforcing bar fixing portions 52 may be fixedly provided on the inner peripheral surface of the mouth tube main body 51, and each of the reinforcing bar fixing portions 52 may have two small holes 52 a. .
Then, as shown in FIG. 6, a mouth tube 50 in which four reinforcing bar fixing portions 52 are fixed on the inner peripheral surface of the mouth tube main body 51 may be used.
Of course, the mouth tube 50 in which eight reinforcing bar fixing portions 52 each having one small hole 52 a are fixed to the inner peripheral surface of the mouth tube body 51 may be used.

As shown in FIGS. 7A, 7B, and 7C, a slit 52b into which the flexible reinforcing bar 10 is inserted is formed in the reinforcing bar fixing portion 52 fixed to the inner peripheral surface of the mouth tube main body 51. The mouth pipe 50 may be used. Eight slits 52b are formed in the reinforcing bar fixing portion 52 of the mouth tube 50 shown in FIGS. 7 (a) and 7 (b).
The slit 52 b extends in a direction from the inner edge to the outer edge of the reinforcing bar fixing portion 52. The slit 52b of the present embodiment extends in a crank shape from the inner edge of the reinforcing bar fixing portion 52 toward the outer edge. Moreover, the width | variety of the slit 52b has a dimension substantially the same as the thickness of the flexible reinforcing bar 10, for example.
And the upper end fixing tool 12 larger than the width | variety of the slit 52b is fixed by the upper end part 11 of the flexible reinforcing bar 10, The flexible reinforcing bar 10 is inserted in the slit 52b from the side of the inner edge of the reinforcing bar fixing part 52. The top end 11 of the flexible rebar 10 is fixed to the inner peripheral surface of the mouth tube 50 by engaging the top end fixing tool 12 so as to hang over the top surface of the rebar fixing portion 52.
The eight flexible reinforcing bars 10 thus fixed to the inner peripheral surface of the mouth tube 50 are fixed in a state where the upper end side of the reinforcing bar rod 30 is expanded.

(Embodiment 2)
Next, Embodiment 2 of the pile head fixing holding structure for reinforcing bar according to the present invention will be described. The same parts as those in the first embodiment are denoted by the same reference numerals, and only different parts will be described.

  As shown in FIGS. 8A and 8B, the reinforcing bar rod 30 according to the second embodiment is wound around the plurality of flexible reinforcing bars 10 and the plurality of flexible reinforcing bars 10 arranged at appropriate intervals in the circumferential direction. And a plurality of band reinforcements 20.

For example, the reinforcing bar 20 is formed by bending a reinforcing bar into an annular shape and joining both ends by welding. The band 20 is preferably a welded closed band.
Moreover, in order to ensure the assembly accuracy of the reinforcing bar 30, the hoop 20 is preferably a perfect circle.

The flexible rebar 10 is a rebar having flexibility, which is also referred to as a strand rebar, for example, a rebar made of a material that does not cause a problem in strength even when bent to the same degree of curvature as the band rebar 20.
For this flexible rebar 10, for example, a material obtained by twisting materials such as carbon fiber, glass fiber, and aramid fiber in addition to a stranded wire and a wire rope can be used.

The flexible reinforcing bar 10 and the band 20 are connected by a rotation coupling jig (not shown) disclosed in, for example, Japanese Patent Application Laid-Open No. 2006-89960.
The rotary coupling jig is a member that is attached to the intersection of the flexible reinforcing bar 10 and the reinforcing bar 20 and is coupled so that the intersection angle of the flexible reinforcing bar 10 and the reinforcing bar 20 can be adjusted.
Then, when the flexible reinforcing bar 10 is bent in an arc shape so as to twist the reinforcing bar rod 30 shown in FIG. 8A, the crossing angle of the flexible reinforcing bar 10 and the band 20 becomes small, and FIG. 8C and FIG. As shown in the figure, the flexible reinforcing bar 10 is spiraled, and the bar spacing interval of the band 20 is gradually reduced, so that the length of the reinforcing bar 30 can be shortened.

Below, the procedure which builds the reinforcing bar rod 30 of Embodiment 2 in the pile hole H is demonstrated, and the pile head fixation holding structure 100 of the reinforcing rod rod which holds the reinforcing bar rod 30 in the pile hole H is demonstrated.
The rebar rod 30 of the first embodiment described above was of the type that is built into the pile hole H while being assembled at the construction site of the cast-in-place pile, but the rebar rod 30 of the second embodiment is a rebar manufactured at the factory. This is a type in which the anchor 30 is carried into the cast-in-place pile construction site and built into the pile hole H.

The reinforcing bar 30 is manufactured in a factory corresponding to the length of the cast-in-place pile.
The rebar rod 30 manufactured at the factory is bundled with a predetermined band member in a state where the length thereof is shortened and reduced, and is carried into the construction site of the cast-in-place pile.
At the construction site of the cast-in-place pile, as shown in FIG. 9A, a pile hole H is formed by excavating a place where the cast-in-place pile is created, and the mouth tube 50 is formed in the upper opening of the pile hole H. Is installed. Further, a built-in stand 1 is installed immediately above the pile hole H.
Then, using the construction machine 3 such as a crawler crane, the rebar bar 30 in a reduced state is hung on the lifting device 2 such as a winch provided on the mounting base 1.

As shown in FIG. 9B, a band member (not shown) that binds the rebar bar 30 in a contracted state after the reduced bar bar 30 is hung on the lifting device 2 of the mounting base 1. Is removed and the reinforcing bar 30 is extended.
Next, as shown in FIG. 9C, the reinforcing bar 30 is lowered into the pile hole H by the lifting device 2 while extending the reinforcing bar 30.

Then, as shown in FIG. 10 (d), when the reinforcing bar 30 is extended to the designed length and the lower end of the reinforcing bar 30 reaches the vicinity of the bottom surface of the pile hole H, the reinforcing bar 30 is built. The real end.
In this embodiment, after the lower end part of the reinforcing bar rod 30 reaches the vicinity of the bottom surface of the pile hole H, the reinforcing bar rod 30 is lowered into the pile hole H by the lifting device 2 so that the reinforcing bar rod 30 is contracted slightly. The upper end portion 11 of the flexible rebar 10 corresponding to the upper end of 30 is aligned with the rebar fixing portion 52 of the mouth tube 50.

Next, while raising the reinforcing bar 2 slightly by the lifting device 2, the upper end portion 11 of the flexible reinforcing bar 10 is inserted into the small hole 52 a of the reinforcing bar fixing portion 52 from below, and protrudes to a position above the reinforcing bar fixing portion 52. The fixed metal fitting 11b is attached to the tip metal fitting 11a of the upper end portion 11 (see FIG. 2B), and the upper end portion 11 of the flexible rebar 10 is attached to the inner peripheral surface of the mouth tube 50 as shown in FIG. Fix it.
In this way, the pile head fixing holding structure 100 of the reinforcing bar rod is formed by fixing the upper end of the reinforcing bar rod 30 built in the pile hole H to the mouth pipe 50, and the reinforcing rod rod 30 is connected to the pile hole by the pile head fixing holding structure 100. It is made to hold in H and construction of the reinforcing bar 30 is finished.
Then, the cast-in-place pile can be constructed by removing the built-in mount 1 and placing concrete in the pile hole H in which the reinforcing bar 30 is built and held.

  Even by such an erection procedure, it is possible to fix the upper end portion 11 of the flexible rebar 10 corresponding to the upper end of the reinforcing bar 30 to the inner peripheral surface of the mouth tube 50 previously installed in the upper opening of the pile hole H. It is possible to easily assemble the pile head fixing holding structure 100 of the reinforcing bar rod that holds the reinforcing rod rod 30 in a state where it is built in the pile hole H.

  As mentioned above, in order to hold the reinforcing bar rod 30 built in the pile hole H, the pile head fixing holding structure 100 of the reinforcing bar rod of this embodiment uses the mouth pipe 50 previously installed in the pile hole H. By doing so, it is possible to eliminate the loss of work time such as installing or removing temporary facilities, so that a cast-in-place pile can be constructed with high work efficiency.

  In addition, in the above embodiment, although the reinforcing bar rod 30 provided with the eight flexible reinforcing bars 10 was demonstrated to the example, this invention is not limited to this, The flexible reinforcing bar 10 in the reinforcing bar rod 30 is not limited to this. The number is arbitrary, and the number may be appropriately adjusted according to the size of the reinforcing bar 30.

  In addition, it is needless to say that other specific detailed structures can be appropriately changed.

DESCRIPTION OF SYMBOLS 1 Construction stand 2 Lifting device 3 Construction machine 4 Band reinforcement device 5 Strip reinforcement base 6 Drop device 7 Construction stand 8 Drum device 10 Flexible rebar 11 Upper end 11a Tip metal fitting 11b Fixture 12 Upper end fixture 13 Lower part Frame 14 Upper frame 20 Reinforcing bar 30 Reinforcing bar 40 Reinforcing bar 50 Mouth pipe 51 Mouth pipe body 52 Reinforcing bar fixing part 52a Small hole 52b Slit 100 Pile head anchoring holding structure of reinforcing bar H Pile hole

Claims (4)

Reinforcing bar that holds a reinforcing bar rod having a plurality of flexible reinforcing bars arranged at appropriate intervals in the circumferential direction and one or a plurality of band reinforcing bars wound around the plurality of flexible reinforcing bars in a state where it is built in a pile hole A pile head anchoring retention structure
Among the plurality of flexible rebars, at least one flexible rebar protruding upward on the upper end side of the rebar rod is an inner peripheral surface of a substantially cylindrical mouth tube that is installed in advance in the upper opening of the pile hole. Pile head anchoring retention structure of rebar rod, characterized by being fixed to   The reinforcing bar cage according to claim 1, wherein the flexible reinforcing bar is fixed to an inner peripheral surface of the mouth tube, and the flexible reinforcing bar is fixed in a state where the upper end side of the reinforcing bar rod is expanded. Pile head fixing retention structure.   2. The flexible reinforcing bar fixed in an expanded state on the inner peripheral surface of the mouth tube is provided with an annular reinforcing bar so as to be inscribed in the reinforcing bar. The pile head fixing holding structure of the reinforcing bar rod according to 2. The inner peripheral surface of the mouth tube is provided with a reinforcing bar fixing portion to which the flexible reinforcing bar is fixed,
A small hole or slit into which the upper end of the flexible reinforcing bar is inserted is formed in the reinforcing bar fixing part,
A fixing tool larger than the diameter of the small hole or the width of the slit is attached to a position above the reinforcing bar fixing portion in the flexible reinforcing bar inserted into the small hole or the slit. The pile head fixation holding structure of the reinforcing rod as described in any one of Claims 1-3.

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