JP2010196251A - Existing concrete pile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an existing concrete pile capable of simplifying the work for crushing concrete and chipping a reinforcing bar. <P>SOLUTION: A pile body part 12 is formed by concrete, and a concrete part 13 to be removed according to schedule is continuously formed in one end part of the pile body part 12. An outer shell steel pipe 14 is provided on an outer peripheral face of the pile body part 12, and a concrete exposed part 15 having no outer shell steel pipe 14 is formed on an outer peripheral face of the concrete part 13 to be removed according to schedule. A plurality of reinforcing bars 16 in the axial direction are cylindrically arranged and buried in the inside of the pile body part 12 and the concrete part 13 to be removed from the pile body part 12 to the concrete part 13. Pipes 17 for preventing the reinforcing bars 16 in the axial direction from being connected with the concrete part 13 to be removed are fitted into a part corresponding to the concrete part 13 to be removed among the reinforcing bars 16 in the axial direction, respectively. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a prefabricated concrete pile in which a plurality of axial reinforcing bars are embedded in the head of the pile main body.

  When laying precast concrete piles (PHC piles / SC piles) and combining the piles and footings, as shown in FIGS. 7 (a) to 7 (b), the SC piles (outer steel pipe concrete composite piles) 1 The cuts 3 and 4 are made in the outer shell steel pipe 2 at the top of the head, and only the outer shell steel pipe 2 at the head of the pile is peeled off, and the concrete 5 of the pile body is removed as shown in FIGS. Breaking out and reinforcing steel bars 6 embedded in concrete 5 in advance when manufacturing the piles are carried out, and as shown in FIG. 7 (d), the SC pile 1 and the footing 7 are connected via these reinforcing steel bars 6. The method is used.

  As described above, the operation of peeling off the outer shell steel pipe 2 of the SC pile 1 involves cutting the outer shell steel pipe 2 and requires a lot of time and labor. Further, the outer shell steel pipe 2 winds a flat plate. Therefore, there is a possibility that the constrained outer shell steel pipe 2 may be repelled when the outer shell steel pipe 2 is cut in the cutting operation of the outer shell steel pipe 2.

  On the other hand, there is an SC pile in which a concrete cylindrical body is exposed from its end face over a predetermined length and the remaining portion of the concrete cylindrical body is covered with a shell steel pipe. This SC pile has the advantage that it can eliminate the labor in the work of fusing and removing the coated outer shell steel pipe when exposing a plurality of anchor reinforcing bars (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 7-18675 (page 2-3, FIG. 4-5)

  However, even for SC piles that omit some of the shell steel pipes and PHC piles (prestressed high-strength concrete piles) that do not have shell steel pipes, the concrete at the top of those piles is broken and reinforced. Since the work to lift out the reinforcing bars is necessary and time and labor are required for these works, there is a problem that the cost burden increases, and there is a possibility of damaging the internal reinforcing steel bars when crushing concrete.

  This invention is made | formed in view of such a point, and it aims at providing the ready-made concrete pile which can simplify a concrete crushing and reinforcing bar lifting work.

  The invention described in claim 1 includes a pile main body portion formed of concrete, a concrete removal planned portion continuously formed at one end of the pile main body portion, and a concrete portion planned to be removed from the pile main body portion. A plurality of axial rebars embedded inside the pipe, and pipes that are respectively fitted to portions of the axial rebars corresponding to the concrete part to be removed and prevent the connection between the axial rebars and the concrete part to be removed Is a prefabricated concrete pile.

  The invention described in claim 2 is the prefabricated concrete pile according to claim 1, wherein the outer shell steel pipe provided on the outer peripheral surface of the pile main body portion and the outer shell steel pipe molded on the outer peripheral surface of the concrete portion to be removed are provided. It is a precast concrete pile with no exposed concrete part.

  The invention described in claim 3 is the precast concrete pile according to claim 1 or 2, wherein seat plate fitting portions respectively provided at outer end portions of the respective axial rebars, and these seat plate fitting portions are provided. A prefabricated concrete pile comprising a ring-shaped seat plate fitted, screws formed at outer end portions of axial reinforcing bars for fastening the seat plate, and nuts screwed to these screws. .

  According to the invention described in claim 1, a plurality of axial reinforcing bars are provided in the interior of the pile main body portion formed from the concrete to the concrete portion to be removed continuously formed at one end portion of the pile main body portion. Since the pipes are fitted in the portions corresponding to the concrete parts to be removed of these axial rebars and the connection between the axial rebars and the concrete parts to be removed is prevented, these pipes are connected to the axial rebars. It is possible to easily extract only the concrete portion to be removed, which is prevented from being joined, and it is possible to simplify the crushing of concrete and the lifting operation of the axial rebar, and the time, burden and cost required for these operations can be reduced.

  According to the second aspect of the present invention, the outer shell steel pipe is partially removed, and the exposed concrete portion without the outer shell steel pipe is formed on the outer peripheral surface of the concrete portion to be removed. The work of stripping a part can be omitted, and various problems caused during the steel pipe stripping work can be eliminated.

  According to the invention of claim 3, the pile structure in which the outer steel pipe corresponding to the concrete part to be removed is eliminated and the periphery of the axial reinforcing bar corresponding to the concrete part to be removed is covered with the pipe to eliminate the adhesion to the concrete. There is also a risk of reducing the product value by causing cracks in the concrete part to be removed during handling of precast concrete piles when moving within the factory and during construction, but at the outer end of each axial rebar A ring-like seat plate is fitted to the provided seat plate fitting portion, and the seat plate is scheduled to be removed by screws formed on the outer end portions of the respective axial reinforcing bars and nuts screwed to these screws. The concrete part to be removed can be integrated with the pile body part by the pressing action of the ring-shaped seat plate until the tightening and fixing with the nut is released. A decrease in product value, such as cracking of parts can be prevented.

(A) is sectional drawing which shows one Embodiment of the precast concrete pile concerning this invention, (b) is sectional drawing which expanded the b part of (a), (c) expanded c part of (a). Sectional drawing and (d) are sectional drawings which expanded d section of (a). It is a top view of a pile same as the above. It is the III-III sectional view taken on the line of Fig.1 (a). It is the IV-IV sectional view taken on the line of Fig.1 (a). It is the VV sectional view taken on the line of Fig.1 (a). It is explanatory drawing which shows the construction example of a pile same as the above, (a) is a perspective view of a pile same as the above, (b) is a perspective view of the process of removing a concrete planned removal part of the pile same as above, (c) is a concrete planned removal of the same pile. It is a perspective view after removing a part. It is explanatory drawing which shows the construction example of the conventional outer shell steel pipe concrete composite pile, (a) is a perspective view of the state which cut | disconnected the outer shell steel pipe of the same pile, (b) is an outer shell steel pipe of the same pile. The perspective view which shows the state which peeled off the part, (c) is a perspective view which shows the state which protruded the reinforcing bar of the pile same as the above, (d) is sectional drawing which shows the combined state of the pile and footing same as the above.

  Hereinafter, the present invention will be described in detail based on one embodiment shown in FIGS.

  FIG. 1 shows an outer shell steel pipe concrete composite pile (hereinafter referred to as SC pile) 11 as a precast concrete pile, and a pile main body portion 12 is formed of concrete, and a concrete portion 13 to be removed at one end portion of the pile main body portion 12. Are formed continuously. These pile main body portion 12 and the concrete portion 13 to be removed are centrifugally molded in a common centrifugal molding frame.

  As shown in FIGS. 1, 3, and 5, an outer shell steel pipe 14 is provided on the outer peripheral surface of the pile main body 12, and the concrete exposed without the outer shell steel pipe 14 is provided on the outer peripheral surface of the concrete portion 13 to be removed. Part 15 is molded.

  As shown in FIG. 1 (a), a plurality of axial reinforcing bars 16 are arranged in a cylindrical shape as shown in FIGS. 2 to 5 from the pile main body portion 12 to the concrete portion 13 to be removed. Embedded.

  As shown in FIGS. 1 (a), (b), (c) and FIG. 3, the axial rebar 16 and the concrete to be removed are included in the portion corresponding to the concrete part 13 to be removed of these axial reinforcing bars 16. Tubes 17 that prevent the coupling with the part 13 are respectively fitted.

  As shown in FIG. 1 (b), seat plate fitting portions 20 are provided at the outer ends of the respective axial reinforcing bars 16, and these seat plate fitting portions 20 are shown in FIG. 6 (b). As shown in FIGS. 1A and 1B, a ring-shaped seat plate 22 having a through hole 21 is fitted at the position of the axial reinforcing bar, and a screw 23 is formed at the outer end of each axial reinforcing bar 16, respectively. As shown in FIG. 2, the seat plate 22 is fastened by a nut 24 that is screwed with these screws 23.

  As shown in FIGS. 1 (a), (c), (d) and FIG. 4, ring-shaped dividers welded to the upper and lower ends of the outer shell steel pipe 14 are attached to the upper and lower ends of the pile main body 12. A plate 25 and a bottom seat plate 26 are arranged.

  As shown in FIG. 1 (a), on the inner peripheral side of the plurality of axial rebars 16 arranged in a cylindrical shape, a deformed intramuscular ring 27 arranged in the pile main body 12 is provided. On the outer peripheral side of the plurality of tubes 17 arranged in a cylindrical shape, a deformed bar outer ring 28 arranged in the concrete portion 13 to be removed is provided.

  Next, the function and effect of the above embodiment will be described with reference to FIGS.

  As shown in FIG. 1 and FIG. 6 (a), the SC pile 11 in a state where the outer shell steel pipe in the portion of the outer shell steel pipe 14 where cutting / peeling of the top of the pile is removed is removed from the factory centrifugal molding machine. Manufactured by.

  In this SC pile 11, a plurality of axial rebars 16 arranged in a cylindrical shape penetrate the inside of the concrete portion 13 to be removed from the upper end portion of the pile body portion 12, and the tip of each axial rebar 16 Since each part protrudes from the upper end surface of the concrete part 13 to be removed and each of their tip parts is threaded, as shown in FIG. A ring-shaped seat plate 22 having a through-hole 21 at the position of the axial rebar is fitted and fixed by tightening each with a nut 24 screwed to each screw 23, and the pile main body 12 and planned to be removed during handling The risk of cracks and the like in the concrete portion 13 is prevented, and the product function is not impaired.

  The concrete part 13 to be removed corresponds to a part where the conventional concrete is crushed and the rebar is lifted, and a plurality of axial reinforcing bars 16 are arranged in a circle inside the concrete part 13 to be removed. By manufacturing the piles by covering each of the axial rebars 16 with pipes 17 respectively, the concrete of the concrete part 13 scheduled to be removed by these pipes 17 is eliminated and planned to be removed Even if the concrete of the concrete part 13 is not crushed, the concrete part 13 to be removed is separated from the pile body part 12 by lifting the concrete part 13 to be removed by a heavy machine such as a crane as shown in FIG. 6 (b). In this case, only the concrete part 13 to be removed can be pulled out from each axial reinforcing bar 16, and as shown in FIG. 6 (c), the axial reinforcing bar 16 arranged in a cylindrical shape can be shown. It is possible.

  In this way, from the pile main body portion 12 formed of concrete, to the removal planned concrete portion 13 continuously formed at one end portion of the pile main body portion 12, a plurality of axial reinforcing bars 16 are embedded therein. Of these axial rebars 16, pipes 17 are respectively fitted to the portions corresponding to the concrete parts 13 to be removed to prevent the connection between the axial rebars 16 and the concrete part 13 to be removed. It is possible to easily remove only the concrete part 13 to be removed, which is prevented from being connected to the directional reinforcing bar 16, and it is possible to simplify the crushing of concrete and the lifting of the axial reinforcing bar 16, and the time and burden required for these operations. And can reduce the cost. The risk of damaging each axial rebar 16 during the lifting operation can also be prevented.

  In addition, the outer shell steel pipe 14 is partially removed, and the concrete exposed portion 15 without the outer shell steel pipe 14 is formed on the outer peripheral surface of the concrete portion 13 to be removed, so that a part of the outer shell steel pipe 14 is removed to expose the concrete. Stripping work can be omitted, and various problems that occur during steel pipe stripping work can be eliminated. In short, by partially eliminating the outer shell steel pipe 14, problems that occur during the peeling operation of the outer shell steel pipe 14 are eliminated, and the cost reduction effect can also be obtained by eliminating the outer shell steel pipe 14 and the outer shell steel pipe removal process.

  Furthermore, the pile structure that eliminates the outer steel pipe 14 corresponding to the concrete part 13 to be removed, and covers the surrounding axial rebar 16 corresponding to the concrete part 13 to be removed with the pipe 17 to eliminate adhesion with the concrete is Although there is a risk that the pre-removed concrete piles will be cracked during removal and construction, causing cracks in the concrete part 13 to be removed and reducing the product value, it is provided at the outer end of each axial rebar 16 respectively. A ring-shaped seat plate 22 is fitted to the seat plate fitting portion 20 formed, and a seat plate is formed by screws 23 formed on the outer end portions of the respective axial reinforcing bars 16 and nuts 24 screwed to these screws 23. Since 22 is fastened to the concrete part 13 to be removed, the concrete part 13 to be removed can be integrated with the pile main body part 12 by the pressing action of the ring-shaped seat plate 22 until the fastening by the nut 24 is released. To be removed A reduction in product value, such as cracking of discrete portions 13 can be prevented.

  In other words, the pile structure in which the outer steel pipe 14 is eliminated at the time of factory manufacture, the axial rebar 16 in the pile body is covered with the pipe 17 and the adhesion to concrete is eliminated, the prefabricated structure during movement in the factory and during construction When handling concrete piles, it is often the case that a hanging tool is hung in the cavity at both ends of the pile, or a wire rope is wound around two places in the axial direction. The ring-shaped seat plate 22 is fitted to the seat plate fitting portion 20 provided at the outer end portion of each axial reinforcing bar 16, and the outer end portion of each axial reinforcing bar 16 is attached to the outer end portion of each axial reinforcing bar 16. Since the seat plate 22 is fastened to the concrete portion 13 to be removed by the screws 23 formed and the nuts 24 screwed to these screws 23, the compressive force from the ring-shaped seat plate 22 is applied to the concrete portion 13 to be removed. Tighten and fix to act It is, it is possible to prevent deterioration in the quality of products such as cracks in the removal plan concrete section 13.

  The present invention can be used not only for the SC pile 11 but also for a prestressed high-strength concrete pile (PHC pile).

11 Outer shell steel pipe concrete composite pile (SC pile) as precast concrete pile
12 Pile body
13 Concrete part to be removed
14 Outer shell steel pipe
15 Exposed concrete
16 axial rebar
17 tubes
20 Seat plate fitting part
22 Seat plate
23 screws
24 nuts

Claims (3)

A pile body formed of concrete;
The concrete part to be removed continuously formed at one end of this pile body part,
A plurality of axial rebars embedded within the pile body from the pile body to the concrete part to be removed;
A prefabricated concrete pile comprising: a pipe that is fitted in a portion corresponding to the concrete portion to be removed among these axial rebars, and that prevents a connection between the axial rebar and the concrete portion to be removed. An outer shell steel pipe provided on the outer peripheral surface of the pile body,
The precast concrete pile according to claim 1, further comprising: an exposed concrete portion having no outer steel pipe formed on an outer peripheral surface of the concrete portion to be removed. Seat plate fitting portions provided at the outer ends of the respective axial reinforcing bars,
A ring-shaped seat plate fitted to these seat plate fitting portions;
The precast concrete pile according to claim 1 or 2, further comprising: a screw formed at an outer end portion of each axial reinforcing bar for fastening the seat plate, and a nut screwed with the screw.

Images