JP2001011852A - Reinforced concrete pile for pile foundation work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reinforced concrete pile for pile foundation work capable of facilitating the chipping of a pile head after a reinforced concrete pile is driven or developed in the ground. SOLUTION: A reinforced concrete pile 10 has at least a plurality of main bars arranged inside thereof, and it is constituted of a pile head 13 provided to the end on the opposite side to the driving end in the ground and removed after the reinforced concrete pile 10 is driven in the ground and a pile main body section 12 monolithically formed in the pile head 13 in succession. the ends of the main bars 11 arranged in the pile main body section 12 enter the inside of the pile head 13 from the pipe main body section 12, and the length of the ends 11a of the main bars 11 located in the pile head 13 is the length necessary for connecting another reinforcing bar used as an anchor when the pile head 13 is removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reinforced concrete pile for a pile ground business, and more particularly to a reinforced concrete pile for a pile ground industry improved so that a pile head can be easily suspended.

[0002]

2. Description of the Related Art When the ground supporting the foundation is soft and the supporting capacity is insufficient, when the ground immediately below the foundation is hard, the layer is thin and the lower layer is soft, or the same building straddles different layers. In such cases, the pile industry is generally used.

[0003] There are two types of piles used in the pile foundation industry: ready-made piles and cast-in-place piles. The ready-made piles are driven into the ground by applying mechanical energy such as impact, vibration, press-fitting, and the like. Cast-in-place piles are used to make holes in the ground and create concrete or reinforced concrete piles on the spot.

[0004] In the case of a ready-made pile, as described above, mechanical energy is applied to drive the pile into the ground, and then the pile head, which is the upper end, is peeled off (the concrete part is removed by breaking). Conventionally, the hanging of the pile head is generally performed by a manual operation using only the hanging or a hammer and a method using a hydraulic machine.

[0005] In such a pile head suspension, the concrete at the top of the suspension is broken so as not to damage the lower pile part (main part), and the main bar exposed from the broken pile head is anchored to the foundation footing. Then, the extra length is cut off and removed.

On the other hand, in the case of a cast-in-place pile, a hole is drilled in the ground, and a concrete or reinforced concrete pile is formed on the spot. For the purpose of protection, "extra-heavy concrete" was cast on the upper end to form a pile head as a result. Therefore, in the case of cast-in-place piles, the ground is excavated to a predetermined depth after the pile formation, and thereafter, the pile head is suspended in the same manner as described above.

[0007]

However, irrespective of ready-made piles or cast-in-place piles, the hanging of the pile head in the reinforced concrete piles for the pile ground industry is a very troublesome work, and has a great effect on the construction period and construction cost. Was exerted. Because the main reinforcement from the main part of the pile is extending to the pile head, it takes a lot of time to break and remove the concrete part of the pile head where the reinforcement is arranged and expose the main reinforcement. It was hard work.

Recently, a hydraulic machine for hanging a pile head has been developed as described above, or an expanding agent has been mixed in the concrete in advance so that cracks can easily enter the concrete portion of the pile head to be removed. As shown in FIG. 7, in order to reduce the adhesive force between the concrete 1a forming the pile head 1 and the main bar 2, a plastic cap 3 is put on the main bar end 2a that enters the pile head 1 and so on. This has been done, and the labor for hanging work has been somewhat reduced.

SUMMARY OF THE INVENTION An object of the present invention is to solve such a conventional problem, and a pile ground in which a pile head made of a reinforced concrete pile is driven into the ground or can be easily suspended. An object of the present invention is to provide a reinforced concrete pile for industry.

[0010]

SUMMARY OF THE INVENTION The present invention relates to a reinforced concrete pile for use in the pile industry, and is constructed as follows to solve the above-mentioned technical problems. That is, the present invention is a reinforced concrete pile in which at least a plurality of main reinforcing bars are arranged, provided at an end opposite to the driving end to the ground, and removed after the reinforced concrete pile is driven into the ground. The pile head and the pile main part formed continuously and integrally with the pile head, and the end of the main reinforcement arranged inside the pile main part is moved from the pile main part to the inside of the pile head. The end length of the main reinforcing bar located inside the pile head is the length required to connect another reinforcing bar serving as an anchor when the pile head is removed.

<Specific Configuration in the Present Invention> The reinforced concrete pile for the piling industry according to the present invention comprises the above-mentioned essential components, and even if the components are specifically as follows: To establish. The concrete component is characterized in that a protective cap is put on an end of a main bar that enters the pile head from the pile main portion.

[0012] The reinforced concrete pile for pile construction in the present invention is further configured as follows in order to solve the above-mentioned technical problems. That is, the present invention relates to a reinforced concrete pile in which at least a plurality of main reinforcing bars are arranged, provided at an end opposite to the driving end to the ground, and removed after the reinforced concrete pile is driven into the ground. And the main reinforcement that is formed integrally with the pile head, and the main reinforcement that is arranged inside the reinforced concrete pile is arranged only inside the pile main part. A connection device for attaching another reinforcing bar serving as an anchor when the pile head is removed to the pile main portion is arranged on an end face of the pile main portion in a connection portion between the main portion and the pile head.

Further, in the reinforced concrete pile for the pile industry according to the present invention, the connecting device includes a ring-shaped connecting plate and a cylindrical shape attached to one surface of the connecting plate and embedded in the main portion of the pile. A large number of sockets, and these sockets are connection holes for connecting another reinforcing bar serving as an anchor when the pile head is removed from the other surface side of the connection plate. .

According to the reinforced concrete pile for the pile industry according to the present invention, the pile is driven into a predetermined portion of the ground, and then the pile head is removed by a conventional method, for example, using only a suspension, a hammer, or a hydraulic machine. . In the reinforced concrete pile for the piling industry according to the present invention, the end of the main reinforcement arranged in the pile main portion extends only a small length to the pile head.

[0015] The length of the end of the main reinforcement entering the pile head from the pile main portion is determined by, for example, adding another reinforcing bar having a predetermined length anchored to the foundation footing when the pile head is detached and the main reinforcement end is exposed. It can be retrofitted. Therefore, there is practically no reinforcing bars inside the pile head, so that the presence of the main reinforcement does not greatly affect the hanging of the pile head, and the hanging of the pile head can be performed easily and in a short time.

Further, the main reinforcing bar arranged inside the reinforced concrete pile is arranged only inside the pile main portion, and the pile head is removed from the end face of the pile main portion at the connecting portion between the pile main portion and the pile head. In the reinforced concrete pile for pile foundation of the present invention, in which a connecting device for attaching another reinforcing bar serving as an anchor to the pile main part at the time of the pile is not used, the pile head has no main reinforcing bar, so that the pile head can be easily suspended. Can be done.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the embodiment shown in the drawings of a reinforced concrete pile according to the present invention will be described in more detail. FIG. 1 shows a reinforced concrete pile 10 for a pile ground business according to a first embodiment of the present invention. The first embodiment exemplifies a ready-made pile.

The reinforced concrete pile 10 for the pile ground business is
The pile main body 12 in which at least a plurality of main bars 11 are arranged is provided. A pile head 13 is formed integrally with the pile main portion 12 at the end opposite to the lower end of the pile main portion 12 which is the tip of the reinforced concrete pile 10 driven into the ground. This pile head 13 has a pile main body 1
The end 11a of the main bar 11 arranged in 2 is inserted.

The end 11a of the main bar 11 that has entered the pile head 13 is alternately changed in length with respect to the adjacent main bar 11. That is, the end 11a of a certain main bar 11
In the case where the penetration length into the pile head 13 is short, the penetration length into the pile head 13 at the end 11a of the main reinforcement 11 adjacent to the main reinforcement 11 is made relatively longer than the penetration length of the preceding main reinforcement. ing.

However, as a whole, the length of the end 11a of the main bar 11 coming out of the pile main portion 12 and entering the pile head 13 is much shorter than the conventional reinforced concrete pile. Thereby, when the concrete portion 13a of the pile head 13 is broken after the reinforced concrete pile 10 is driven into the ground, the concrete portion 13a is very difficult to demolish because the total amount of the ends of the main bars 11 that have entered the inside is small. Will be easier.

In the reinforced concrete pile 10, as described above, when the concrete portion 13 a of the pile head 13 is broken after being driven into the ground and the inner main bar end portion 11 a is exposed, the upper end of the pile main portion 12 is formed. The end of the main bar that protrudes from the base bar must be long enough to be used as an anchor for the foundation footing. Therefore, this main line 11
Is connected to another end which is substantially an anchor.

In the case of the reinforced concrete pile 10 according to this embodiment, a pressure welding connection is adopted as a method of connecting another reinforcing bar serving as an anchor bar. That is, in the reinforced concrete pile 10, the concrete portion 13 a of the pile head 13 is removed after the pile is driven into the ground, and another reinforcing bar serving as an anchor is easily connected to each end of the exposed main bar 11 by pressure welding. The mutual length of the adjacent main bar ends in the pile head 13 is changed in advance.

FIG. 2 shows a reinforced concrete pile 20 for a pile construction business according to a second embodiment of the present invention.
The reinforced concrete pile 20 includes a pile main body 22 in which at least a plurality of main reinforcements 21 are arranged similarly to the first embodiment described above. Pile main part 22 which is the tip of reinforced concrete pile 20 driven into the ground
A pile head 23 is formed integrally with the pile main body 22 at the end opposite to the lower end of the pile. The end 21a of the main bar 21 arranged in the pile main portion 22 enters the pile head 23 by a small length.

The length of the end 21a of the main reinforcement 21 arranged in the pile main portion 22 into the pile head 23 is such that the concrete portion 23a of the pile head 23 is removed after the reinforced concrete pile 20 is driven into the ground. The length is the minimum length necessary for connecting another reinforcing bar serving as an anchor to each end 21a of the exposed main bar 21 by welding. As shown in an enlarged manner in FIG. 3, an end 21a of the main bar 21 which enters the pile head 23 is covered with a cylindrical plastic cap 24.

When the cap 24 is put on the end 21a of the main bar 21 which has entered the pile head 23, the adhesion between the concrete portion 23a forming the pile head 23 and the main bar end is almost eliminated. Since there is no pile portion 23, the concrete portion 23 of the pile head 23 can be easily moved from the pile main portion 22 by raising the pile head 23 upward by making a crack or a notch in the concrete near the division line 25 between the pile head and the pile main portion.
a can be separated and removed.

After the concrete portion 23a of the pile head 23 is separated and removed from the pile main portion 22, another reinforcing bar serving as an anchor bar is connected to the end 21a of the main reinforcement 21 projecting from the pile main portion 22 by welding. This is used as an anchor for basic footing.

In the reinforced concrete piles for the pile ground industry according to the first and second embodiments described above, the main reinforcing bars 11 projecting from the upper ends of the pile main portions 12 and 22 after the pile heads 13 and 23 are attached. In the example described above, another reinforcing bar serving as an anchor is connected to the end portion 21 by pressure welding and welding, but a connecting method using a mechanical joint may be used.

FIG. 4 shows a reinforced concrete pile 30 for pile construction according to a third embodiment of the present invention.
The reinforced concrete pile 30 includes a pile main portion 32 in which at least a plurality of main reinforcements 31 are arranged as in the first embodiment described above. Pile main part 32 which is the tip of reinforced concrete pile 30 driven into the ground
A pile head 33 is formed integrally with the pile main portion 32 at an end opposite to the lower end.

The end of the main bar 31 arranged in the pile main portion 32 terminates at the boundary 36 between the pile main portion 32 and the pile head 33, and the end of the main bar 31 extends over the pile head 33. Not in. However, on the end face of the pile main portion at the boundary portion 36 between the pile main portion 32 and the pile head 33, a connecting device 3 for attaching another reinforcing bar serving as an anchor bar to the pile main portion 32 when the pile head 33 is removed.
4 are arranged.

The connecting device 34 comprises a ring-shaped connecting plate 34a as shown in FIGS. 5 and 6, and has a cylindrical shape embedded in the pile main portion 32 on one surface of the connecting plate 34a. Many sockets 34b are attached. Each of these sockets 34b is a screw hole 34c for screwing another reinforcing bar 35 serving as an anchor bar when the pile head 33 is removed from the other surface side of the connecting plate 34a.

According to such a reinforced concrete pile 30, after the reinforced concrete pile 30 is driven into the ground, cracks or cuts are made in the concrete near the boundary 36 between the pile head 33 and the pile main portion 32. Pile head 3
3 is pulled up. Since the end of the main bar 31 does not extend into the pile head 33 as described above, the pile head 33 can be easily separated and removed from the pile main body 32.

When the pile head 33 is removed from the pile main portion 32, the connecting plate 34a of the connecting device 34 is exposed on the upper end surface of the pile main portion 32 as shown in FIG. Another reinforcing bar 3 serving as an anchor in the screw hole 34c
5 are screwed together so that the main bar projects from the upper end surface of the pile main body 32.

The socket 34 in the connecting device 34
It is necessary that the screw hole 34c of b be closed with a suitable lid when the pile head 33 is formed, or that the inside thereof be padded to prevent concrete from entering.

The reinforced concrete pile for the pile industry according to each of the above-described embodiments has been described as an example of a so-called ready-made pile (a reinforced concrete pile formed in advance in a factory or the like). Needless to say, the present invention can be similarly applied to a cast-in-place pile. Rather, in practice, it would be more useful to apply the invention to cast-in-place piles.

[0035]

As described above, according to the reinforced concrete pile for the pile ground business of the present invention, since there is virtually no reinforcement inside the pile head, the main reinforcement is attached to the suspension of the pile head. The pile head is not easily affected in a short time after a pile made of reinforced concrete is driven or formed in the ground without greatly affecting the existence of the pile.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view partially showing an upper part of a reinforced concrete pile for pile construction according to a first embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view partially showing an upper part of a reinforced concrete pile for pile ground industry according to a second embodiment of the present invention.

FIG. 3 is an enlarged cross-sectional view partially showing a configuration of an end of a main reinforcing bar near a boundary between a pile main portion and a pile head of a reinforced concrete pile for pile foundation according to the second embodiment shown in FIG. 2; is there.

FIG. 4 is a schematic cross-sectional view partially showing an upper part of a reinforced concrete pile for pile construction according to a third embodiment of the present invention.

FIG. 5 is a perspective view showing an anchor rebar connecting device used for the reinforced concrete pile shown in FIG. 4 for the pile ground industry.

FIG. 6 shows a third embodiment of the reinforced concrete pile according to the third embodiment shown in FIG. 4, in which a pile head is removed, and then an anchor bar is screwed into an anchor bar connecting device existing on the end face of the pile main portion. It is a partial sectional view expanding and showing a state.

FIG. 7 is a schematic front view showing a part of an upper part of a conventionally used reinforced concrete pile for a pile ground industry partially broken away.

[Explanation of symbols]

 Reference Signs List 10 reinforced concrete pile 11 main reinforcement 11a main reinforcement end 12 pile main part 13 pile head 13a concrete part 20 reinforced concrete pile 21 main reinforcement 21a main reinforcement end 22 pile main part 23 pile head 23a concrete part 24 cap 30 reinforced concrete pile 31 main reinforcement 31a main reinforcement End 32 Pile main body 33 Pile head 23a Concrete part 34 Anchor bar connecting device 34a Connecting plate 34b Socket 34c Screw hole (connecting hole) 35 Anchor bar

Claims (4)

[Claims] 1. A reinforced concrete pile having at least a plurality of main reinforcing bars disposed therein, the reinforced concrete pile being provided at an end opposite to a driving end into the ground, being removed after the reinforced concrete pile is driven into the ground. And a pile main portion formed continuously and integrally with the pile head, and an end of a main reinforcing bar arranged inside the pile main portion is separated from the pile main portion by the pile main portion. It is characterized in that the end length of the main reinforcing bar that enters the head and is located in the pile head is a length necessary for connecting another reinforcing bar serving as an anchor when the pile head is removed. Piles made of reinforced concrete for the piling industry. 2. The reinforced concrete pile according to claim 1, wherein a protective cap is put on an end of the main reinforcing bar that enters the pile head from the pile main portion. . 3. A reinforced concrete pile having at least a plurality of main reinforcing bars disposed therein, the pile being provided at an end opposite to a driving end into the ground, and removed after the reinforced concrete pile is driven into the ground. And a main pile portion formed continuously and integrally with the pile head, and the main reinforcing bars arranged inside the reinforced concrete pile are arranged only inside the main pile portion. A connection device that attaches another reinforcing bar serving as an anchor when the pile head is removed to the pile main body is disposed on the pile main body end surface at the boundary between the pile main body and the pile head. Pile made of reinforced concrete for the pile industry. 4. The connecting device, comprising: a ring-shaped connecting plate;
A large number of cylindrical sockets attached to one surface of the connection plate and embedded in the pile main body,
4. A connection hole for connecting another reinforcing bar serving as an anchor when the pile head is removed from the other surface side of the connection plate.
4. A reinforced concrete pile for use in piles according to 1.