JP4993744B2 - Ready-made concrete piles - Google Patents

Description

The present invention relates to a hollow cylindrical ready-made concrete pile provided with an end plate at the end of the pile main body, and by attaching a rod-shaped bracket for suspension using the end plate to the end of the pile main body, The pile can be suspended in the vertical direction.

  Generally, pre-stressed concrete piles are centrifugally formed into a hollow cylindrical shape and prestress is introduced by inserting a plurality of tendons in the axial direction. Moreover, the end plate is attached to the edge part of a pile main body for the objectives, such as a coupling for joining piles.

  By the way, in order to build this kind of ready-made concrete pile in the pile hole, generally, the wire for suspension is wound around the pile body, or the hook of the wire for suspension is attached to the suspension bracket attached in advance to the end of the pile body. The pile was hung in the vertical direction.

  As an example of the former, for example, Patent Document 1 describes a method of hanging a pile by hooking a first wire hung on the pile on a hanging tool.

  In Patent Document 2, the lower end of the mounting wire is hung on the pile, the upper end of the wire is hung on the hook of the mobile crane and wound up to a predetermined height, and then the boom of the crane is shaken to hang the hook. A method is described in which the pile is lifted by clamping the mounting wire to the pile by moving to the side.

  On the other hand, as an example of the latter, for example, in Patent Document 3, a pair of brackets are provided on the outer peripheral portion of the upper end portion of the upper pile so as to protrude in the radial direction of the upper pile, and a ring is attached to the end portion of the pile lifting wire. The ring is attached to the hole of the bracket via a shackle, and the method of lifting the upper pile by hanging the pile lifting wire on the hook of the crane is described.

  Further, Patent Document 4 discloses a clamping pipe divided body obtained by dividing a pipe for inserting a ready-made pile in the circumferential direction, and a pair of swinging projections provided so as to be able to swing in the vicinity of a mating portion of the clamping pipe divided body. A method of lifting a ready-made pile by attaching a hanging bracket of a pile consisting of a piece to the upper end portion of the ready-made pile and attaching a suspension wire to the swinging piece of this hanging fitting is described.

JP 7-229144 A JP-A-6-336728 JP-A-8-158359 JP 2007-146519 A

  However, in the former method, as the pile diameter increases, winding of the wire becomes considerably difficult, and there is a problem in work safety.

  Moreover, when the winding position of the wire is bad, the pile may not be easily suspended in the axial direction by being suspended in a substantially vertical balance, and there is a problem in construction accuracy. Furthermore, there was a problem in durability such as deterioration of the wire to be wound.

  On the other hand, in the latter method, it is necessary to attach a new hanging metal fitting or jig to the upper end of the pile body, or this metal fitting is attached to the front side of the end plate by welding or the like. When piles with heavy pile weights were built because they were buried, there were problems with corrosion deterioration of fixed parts such as welding and the strength and durability of concrete.

  Furthermore, when this metal fitting is attached in a state protruding from the end of the pile body, there is a problem that the work becomes troublesome when joining the piles.

The present invention has been made to solve the above-mentioned problems, and can be applied to a pile having a heavy pile weight without considering the strength and durability of a portion to which a load is applied during suspension. An object is to provide a ready-made concrete pile that can be easily suspended in a vertical direction using a wire.

The ready-made concrete pile according to claim 1 is provided with an end plate at the end of the pile main body and a rod-shaped metal fitting for suspension attached across the hollow portion of the pile main body, and both ends of the metal rod are at the ends of the pile main body. It is fixed to the back surface of the end plate in a state of being embedded in concrete, an end portion of a tension material for introducing prestress in the axial direction of the pile body is fixed to the end plate, and the prestress is fixed to the rod-shaped metal fitting. In a hollow cylindrical ready-made concrete pile that is configured to act also, a part of the tension material is configured by being arranged through a through hole formed in an end portion of the rod-shaped metal fitting. It is what.

  That is, this invention attaches the rod-shaped metal fitting for suspension using the end plate to the end of the pile body, and the pile is easily omitted in the vertical direction of the pile by using the wire for hanging. It can be hung vertically.

  Attach the rod-shaped bracket across the hollow part of the pile body, and fix both ends of the pile to the back of the end plate in the concrete of the pile body without protruding from the pile. In addition to preventing the hindrance when molding and joining the piles, the rod-shaped metal fitting is firmly attached to the end of the pile body.

  In this case, the rod-shaped bracket can be fixed by welding both ends to the end plate or screwed to the end plate. In addition, a bent portion can be provided and fixed, and the method of fixing the rod-shaped metal fitting to the end plate is not particularly limited. Also, the mounting position of the rod-shaped bracket is not particularly limited, but when using two or more rod-shaped brackets in relation to the lifting part of a lifting jig such as a hook, the hollow portion is as much as possible for stability and the function of the hollow portion. It is better to install on the outside.

In addition, by fixing both ends of the rod-shaped bracket to the back of the end plate, for the pre-stress-introduced pile, the pre-stress introduced to the pile by the tension material with the end fixed to the end plate is fixed to the rod-shaped bracket. It can also be used to give the rod-shaped bracket a high pulling strength .

Furthermore, by arranging a part of the tendon through a through-hole formed at the end of the bar-shaped bracket, the bar-shaped bracket can be easily and firmly attached using the tendon, and the prestress can be attached to the bar-shaped bracket. It becomes easy to act on.

  Therefore, when the pile is lifted in the vertical direction with the hook of the lifting wire, even if a large pulling force acts on the rod-shaped bracket, the end of the rod-shaped bracket may be detached from the end of the pile body. It's hard to fall.

  In addition, since multiple tension members are arranged at predetermined intervals in the circumferential direction of the pile according to the pile diameter, the end of the tension material closest to the end of the rod-shaped bracket is formed at the end of the rod-shaped bracket. It is possible to easily attach the rod-shaped metal fitting only by passing through the formed through hole.

  The end of the pile body is attached to the end of the pile body using the end plate, and the end is strengthened by attaching it over the hollow part of the pile body. A pile can be suspended substantially vertically in the vertical direction by a suspension wire without using a jigging tool or a suspension device.

  In addition, by fixing both ends of the rod-shaped bracket to the back of the end plate without protruding from the pile in a state embedded in the concrete, the rod-shaped bracket can be used when centrifugally forming the pile or joining the piles together. There is no obstacle.

  In addition, it is possible to cope with a pile having a heavy pile weight without considering the strength and durability of the fixed portion that is loaded when suspended.

  Furthermore, for prestressed piles, both ends of the rod-shaped bracket are fixed to the back surface of the end plate, so that the prestress introduced into the pile by the tension material fixed at the end plate to the end plate It can also be used to secure the rod, and the rod-shaped bracket can have a high pulling strength.

  Moreover, according to the manufacturing method of this invention, the prestress introduction pile made from concrete provided with the metal fitting for suspension can be manufactured easily, utilizing the conventional manufacturing process as it is.

  FIGS. 1-6 shows an example of this invention, and in FIGS. 1-3, the ready-made concrete pile 1 of the end plate 3 and the pile main body 2 which were attached to the both ends of the pile main body 2 and the pile main body 2, respectively. A rod-shaped metal fitting 5 is attached to the end of a conventional ready-made concrete pile composed of a plurality of tension members 4 inserted in the axial direction.

  In this example, the pile body 2 is formed into a prestress-introduced pile in which prestress is introduced in the axial direction of the pile body 2 by a plurality of tension members 4 that are centrifugally formed from reinforced concrete into a cylindrical shape. is there. The prestress to introduce is the same as before.

  A PC steel material is used for the tension members 4, and a plurality of the tension members 4 are inserted at regular intervals in the circumferential direction of the pile body 2, and the end portions 4 a of the tension members 4 penetrate the fixing holes 3 a formed in the end plates 3. The fixing is performed by engaging the end 4a with the peripheral edge of the fixing hole 3a.

  The end plate 3 is formed in a hollow flat plate shape having the same shape as the cross-sectional shape of the pile body 2, attached to both ends of the pile body 2, prestress is introduced into the pile body 2 by the tension material 4, and concrete is used. It is fixed.

  The rod-shaped metal fitting 5 is a receiving member for locking the hook 7 attached to the hoisting wire 6 when the pile 1 is hung with the hoisting wire 6, and in the example of FIGS. Two are attached to the end of the pile main body 2, and both sides sandwiching the axis of the hollow portion 2 a of the pile main body 2 are attached across the diameter direction.

  The mounting position of the rod-shaped metal fitting 5 is only required to secure a space surrounded by the end plate 3 and the rod-shaped metal fitting 5 so that the hook 7 can be locked. This is in order not to obstruct the mud discharged from the pile hollow portion. Although the material of the rod-shaped metal fitting 5 to be used is not limited, steel is desirable.

  The shape may be a round bar or a square bar, a deformed bar as shown in FIG. 5 (f), or a square bar as shown in FIGS. 5 (e) and 5 (g). The deformed bar shown in (f) of FIG. 5 has an uneven surface so that the hook 7 can be prevented from skidding and the center of the bar-shaped metal fitting 5 can be suspended.

  Further, the square bar shown in FIG. 5 (e) is formed with a groove-like portion 5c that opens directly below as a portion for locking the hook 7 at the center of the rod-shaped metal fitting 5, thereby preventing the skid from slipping. The center of the rod-shaped metal fitting 5 can be suspended.

  Furthermore, the square bar shown in FIG. 5 (g) is provided with stoppers 5d and 5d for preventing the side slip of the hook 7 at the center of the bar-shaped metal fitting 5, so that the side slip of the hook 7 can be prevented. The center of the rod-shaped metal fitting 5 can be suspended.

  Furthermore, the dimension of the rod-shaped metal fitting 5 changes with kinds of pile. For example, when the inner diameter of the pile main body 2 is 740 mm, the diameter of the rod-shaped metal fitting 5 may be about 50 mm in length and width and about 640 mm in length, which is approximately spaced by about 540 mm on both sides from the center of the two pile main bodies 2. What is necessary is just to attach in parallel.

  In the above case, fixing holes 5b and 5b are provided at both ends 5a of each bar-shaped metal fitting 5, and the end 4a of the tension member 4 passes through the fixing hole 5b, so that the bar-shaped metal fitting 5 is attached to the end plate. 3 is fixed to the end of the pile body 2.

  Thus, it is preferable to provide fixing holes 5b and 5b at both ends 5a and 5a of the rod-shaped metal fitting 5 in order to fix easily and firmly using the tension material 4.

  Further, both end portions 5 a, 5 a of each bar-shaped metal fitting 5 are embedded in the concrete of the pile main body 2 on the back surface of the end plate 3, and are also fixed by prestress by the tension material 4 acting via the end plate 3. .

  In addition, in piles other than the prestress introduction pile fixed by the effect | action of prestress introduction, what is necessary is just to fix the both ends 5a and 5a of the rod-shaped metal fitting 5 directly to the end plate 3 by fillet welding. FIG. 6 shows an example in which both end portions 5 a and 5 a of the rod-shaped metal fitting 5 are fixed to the back surface of the end plate 3 by fillet welding 8.

  4 (a) and 4 (b) show an example in which three bar-shaped metal fittings 5 are attached to the end of the pile main body 2. In this case, the three bar-shaped metal fittings 5 are the pile main body 2; The hollow portion 2a is attached in a plane triangular shape so as to surround the three sides sandwiching the axis of the hollow portion 2a. Moreover, the both ends 5a and 5a of each rod-shaped metal fitting 5 are being fixed to the edge part of the pile main body 2 by the fixing method shown in the previous example.

  The number of rod-shaped metal fittings 5 used is not particularly limited, but is preferably 2 to 3 as in the above example, from the viewpoint of ease of mounting, stability when lifted, functionality of the hollow portion 2a in excavation work, and the like. If three are used, the stability when lifted is improved.

  In the above example, an example of a prestress-introduced pile is shown, but it goes without saying that the present invention can be applied to a ready-made concrete pile that does not introduce prestress.

  Hereinafter, an embodiment of a method for producing a ready-made concrete pile of the present invention will be described.

  First, a rebar cage is assembled that includes a plurality of tendons arranged at a predetermined interval and rebars arranged in a spiral around the tendons.

  Next, a rod-shaped metal fitting is attached to the end portion on one end side of the rebar cage, and end plates are attached to both end portions, respectively. At that time, the rod-shaped metal fitting is attached to the end of the reinforcing bar cage by passing the end of the tendon through the through hole formed in the end of the rod-shaped metal fitting.

  The end plate is attached to the end of the rebar cage by fixing the end of the tendon to the fixing hole formed in the end plate. In particular, the end of the tendon on the side where the rod-shaped bracket is attached is the rod-shaped bracket. The tip is fixed in the fixing hole of the end plate.

  Next, the above-mentioned reinforcing steel basket is set in the lower formwork of the ready-made concrete pile forming formwork. Next, put concrete into the lower formwork (placement by filling type), then install the upper formwork on the lower formwork, assemble the formwork, and put the tension material through the end plate get nervous.

  Next, the concrete in the mold is compacted by centrifugal molding and then steam-cured. Then, after demolding, prestress is introduced into the concrete.

  With the above manufacturing method, a prestressed pile made of concrete having a rod-shaped metal fitting for suspension can be easily manufactured while using the conventional manufacturing process as it is.

  In addition, as a method of throwing concrete into the ready-made concrete pile forming formwork, after setting the rebar cage in the lower formwork, install the upper formwork on the lower formwork and assemble the formwork first, After that, there is also a method of placing concrete in the mold by a pressure feeding method or an injection method.

  Since the ready-made concrete pile of the present invention can be suspended substantially vertically in the vertical direction by using the rod-shaped bracket by firmly attaching the rod-shaped bracket for suspension to the end of the pile body. It is possible to simplify the construction of piles and reduce costs.

It is a perspective view which shows an example of the ready-made concrete pile of this invention. The ready-made concrete pile shown in FIG. 1 is shown, (a) is a top view, (b) is the sectional view on the AA line in (a). It is a reverse view of the end plate which shows the attachment state of a rod-shaped metal fitting. The other example of the ready-made concrete pile of this invention is shown, (a) is a top view, (b) is a back view of an end plate. (a)-(g) is a perspective view which shows the modification of a rod-shaped metal fitting. It is a back view of the end plate which shows the example of attachment by welding of a rod-shaped metal fitting.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ready-made concrete pile 2 Pile main body 2a Hollow part 3 End plate 3a Fixing hole 4 Tensile material 4a End of tension material 5 Bar-shaped metal fitting 5a End part 5b of bar-shaped metal fitting 5c Groove-shaped part 5d Stopper 6 Suspension wire 7 Hook 8 Fillet welding

Claims (1)

Provided with an end plate at the end of the pile body and a rod-shaped metal fitting for suspension that is mounted across the hollow part of the pile main body, both ends of the rod-shaped metal fitting being embedded in the concrete of the pile body The end plate is fixed to the end plate, and the end portion of the tension material for introducing prestress in the axial direction of the pile body is fixed to the end plate, and the prestress is applied to the rod-shaped metal fitting. A ready-made concrete pile having a hollow cylindrical shape , wherein a part of the tension material is arranged through a through hole formed in an end portion of the rod-shaped metal fitting .

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