JP2010255394A - Sc pile, manufacturing method therefor, and pile head treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an SC (Steel and Concrete) pile capable of exposing easily an anchor reinforcement embedded preliminarily, and capable of treating easily a pile head in a short time, a manufacturing method therefor, and a pile heat treatment method. <P>SOLUTION: A reinforcement cage 5 is embedded in a concrete layer 3 of a pile head part, the reinforcement cage 5 includes a partitioning plate 6 with an outer circumference fixed to the inner circumference of a steel pipe 2, to partition the pile head concrete layer 3 into a pile head upper side 3a and a pile head lower side 3b, and the plurality of anchor reinforcements 7 provided with a space in a circumferential direction on the partitioning plate 6, and extended respectively in the pile head upper concrete layer 3a and the pile head lower concrete layer 3b, the anchor reinforcement 7a of the pile head part upper concrete layer 3a is covered with a coating pipe 11, and the upper end of the coating pipe 11 is connected to a pile end plate 13. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an SC pile, a manufacturing method thereof, and a pile head processing method, and more particularly, to a technique for dealing with a pile head process applied for joining a pile head and a structure foundation.

  In recent years, from the viewpoints of short construction period and low cost, the support capacity of ready-made concrete piles has increased, and even with piles of the same diameter compared to conventional embedded pile construction methods, the support capacity has become 2-3 times greater. For this reason, since the horizontal force which one pile bears at the time of an earthquake became larger than before, the example which adopts SC pile (concrete pile with an outer shell steel pipe) which has a large yield strength with a small diameter has increased.

  As one of such SC piles, one in which an anchor reinforcing bar for joining to a structure foundation is embedded in a concrete layer of a pile head in advance is known (see, for example, Patent Document 1). This SC pile with anchor reinforcement has the advantage that the welding work to the steel pipe of the anchor reinforcement after pile construction performed conventionally is unnecessary. However, on the other hand, the anchor reinforcing bars previously embedded in the concrete layer must be exposed, and the pile head processing requires a lot of labor and labor. That is, after the pile construction, the steel pipe of the pile head is cut in the circumferential direction and the axial direction, the crusher is put inside the pile head, the concrete is crushed, and the concrete around the anchor rebar is beaten, and the pile end plate It is necessary to work such as cutting the anchor and reinforcing bar.

Japanese Patent Laid-Open No. 7-18675

The present invention has been made based on the technical background as described above, and achieves the following object.
An object of the present invention is to provide an SC pile that can easily expose an anchor reinforcing bar embedded in advance and can easily perform pile head processing in a short time, a manufacturing method thereof, and a pile head processing method. .

The present invention employs the following means in order to achieve the above object.
That is, this invention is an SC pile having a pile end plate that covers the end of the concrete layer at the pile head end while having a cylindrical concrete layer on the inner periphery of the steel pipe,
Reinforcing bar is embedded in the concrete layer of the pile head,
This reinforcing bar is an annular partition plate whose outer periphery is fixed to the inner periphery of the steel pipe so as to partition the pile head concrete layer into the pile head upper side and the pile head lower side,
A plurality of anchor reinforcing bars extending to each of the pile head upper side concrete layer and the pile head lower side concrete layer are provided at intervals in the circumferential direction on this partition plate,
The anchor reinforcing bar of the pile head upper side concrete layer is covered with a covering pipe, and the upper end portion of the covering pipe is connected to the pile end plate.

  More specifically, the pile end plate is provided with a plurality of holes at intervals in the circumferential direction, and the upper ends of the respective coated pipes are inserted into these holes. An auxiliary plate is fixed to the surface of the pile end plate, and the auxiliary plate has a plurality of protrusions spaced apart in the circumferential direction, and each protrusion is inserted into the covering pipe.

Further, the present invention is a method for manufacturing an SC pile, the step of attaching a plurality of anchor reinforcing bars extending on both sides of the annular partition plate in the circumferential direction to make a reinforcing bar rod,
A process of covering a covered pipe on an anchor reinforcing bar on the pile head upper side;
Placing the rebar rod in a steel pipe, and fixing the outer periphery of the partition plate to the inner periphery of the steel pipe;
Fixing the pile end plate to the steel pipe end, and connecting the end of the covered pipe to the pile end plate;
And a step of supplying concrete into the steel pipe and forming a concrete layer embedded with the reinforcing steel bar on the inner periphery of the steel pipe by centrifugal molding.

Furthermore, this invention is a pile head processing method of the SC pile,
After burying the SC pile in the ground, the step of cutting the steel pipe in the circumferential direction at the partition plate position;
The pile head upper portion including the concrete layer above the pile head above the partition plate and the steel pipe portion on the outer periphery thereof is pulled out and removed, and the anchor rebar on the pile head upper side is exposed. It is in the pile head processing method of SC pile characterized by these.

  According to the present invention, the concrete part of the pile head of the SC pile is embedded with the reinforcing bar rods having the partition plates and the anchor reinforcing bars that divide this into the pile head upper side and the pile head lower side, and the pile head upper side concrete Since the anchor rebar of the layer is covered with the covering pipe, the anchor rebar can be exposed only by cutting the steel pipe in the circumferential direction and pulling out the upper part of the pile head above the partition plate. Therefore, the axial cutting of the steel pipe, the crushing of the concrete layer, and the turning work are completely unnecessary, and the pile head processing work can be performed very easily.

It is an axial sectional view of a pile head which shows an embodiment of this invention. It is AA arrow sectional drawing of FIG. It is a BB arrow directional cross-sectional view of FIG. It is a figure which shows embodiment of a pile head processing method.

  Embodiments of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 to 3, the SC pile is a ready-made pile having a cylindrical concrete layer 3 on the inner periphery of the steel pipe 2. The figure shows only the pile head 1 of the SC pile, and an end of the pile head 1 is provided with an annular pile end plate 4 whose outer periphery is welded to the steel pipe 2 and covers the end of the concrete layer 3.

  A reinforcing bar 5 is embedded in the concrete layer 3 of the pile head 1. The reinforcing bar 5 is mainly composed of an annular partition plate 6 and a plurality of anchor reinforcing bars 7. The partition plate 6 is a member that divides the concrete layer 3 of the pile head 1 into a pile head upper side concrete layer 3a and a pile head lower side concrete layer 3b at the boundary, and the outer periphery thereof is the inner periphery of the steel pipe 2 Fixed to the lower part of the pile head by welding. Hereinafter, not only the concrete layer 3 but also other members, with the partition plate 6 as a boundary, the upper side is referred to as the pile head upper side and the lower side is referred to as the pile head lower side.

  The partition plate 6 is provided with a plurality of holes 8 at intervals in the circumferential direction, and the anchor rebar 7 passes through these holes 8, that is, the pile head upper side concrete layer 3 a and the pile head lower side concrete layer. It arrange | positions so that it may extend in each of 3b. These anchor reinforcing bars 7 are fixed to the partition plate 6 by welding on the lower side 7b of the pile head. The anchor reinforcing bars 7 b on the lower side of the pile head are fixed to each other by the hoop bars 9 and fixed to the inner periphery of the steel pipe 2 by the fixing bars 10.

  The anchor reinforcing bar 7 a on the upper side of the pile head is covered with a covering pipe 11. The covering pipe 11 is for cutting the edge between the anchor reinforcing bar 7a and the concrete layer 3a, and a light pipe such as a vinyl chloride pipe or a polystyrene foam pipe is used. The pile end plate 4 is provided with a plurality of holes 12 at intervals in the circumferential direction, and the upper end portion of the covering pipe 11 is connected to the pile end plate 4 by being inserted into the hole 12.

  An annular auxiliary plate 13 is fixed to the pile end plate 4. The auxiliary plate 13 has a plurality of projections 14 spaced in the circumferential direction, and each projection 14 is inserted into the covering pipe 14. The concrete layer 3 is formed by centrifugal molding, and a large centrifugal force acts on the coated pipe 11 at the time of molding. The covering pipe 11 is light as described above and has low rigidity, and if it is left as it is, deformation occurs during molding. The projection 14 is for inserting the projection 14 into the coated pipe 11 to increase the apparent rigidity of the coated pipe 11 and prevent deformation. Therefore, the length of the protrusion 14 is appropriately selected according to the length of the anchor reinforcing bar 7a of the pile head upper concrete layer 3a. On the contrary, if the length of the anchor reinforcing bar 7a is such that it enters the hole 12 of the pile end plate 4, the auxiliary plate 13 with the protrusions 14 is not necessary. In the figure, the protrusion 14 is a hollow tube, but it may be solid.

  The auxiliary plate 13 is not limited to a single plate, and may be configured to have one auxiliary plate for each protrusion 14. In this case, a plurality of auxiliary plates are arranged in a ring shape. That is, the “annular auxiliary plate” in this specification is a concept including not only one annular auxiliary plate but also a plurality of auxiliary plates arranged in an annular shape.

  Next, the manufacturing method of the said SC pile is demonstrated.

(1) Manufacture of reinforcing bar rod 5 A plurality of anchor reinforcing bars 7 are passed through holes 8 provided in the partition plate 6. Due to the penetration, the anchor reinforcing bars 7 extend to both sides of the partition plate 6, one side of which is embedded in the pile head upper side concrete layer 3 a and the other side is embedded in the pile head lower side concrete layer 3 b. And each anchor reinforcement 7 is welded to the partition plate 6 in the position used as the pile head lower part side. Moreover, while fixing the hoop reinforcement 9 to the edge part of the anchor reinforcement 5 used as the pile head lower part side, the fixed reinforcement 10 is attached.

(2) Attaching the covered pipe 11 Each anchor reinforcing bar 7a on the upper side of the pile head is covered with a covered pipe 11 such as a vinyl chloride pipe or a polystyrene foam pipe. The covering pipe 11 may be attached after the next reinforcing bar 5 is set.

(3) Set of reinforcing bar 5 The reinforcing bar 5 is disposed in the steel pipe 2, and the outer periphery of the partition plate 6 is welded to the inner periphery of the steel pipe 2 on the lower side of the pile head. Further, the fixed reinforcing bar 10 is welded to the inner periphery of the steel pipe 2.

(4) Attaching the pile end plate 4 Insert the end of each coated pipe 11 into the hole 12 of the pile end plate 4 and weld the pile end plate 4 to the end of the steel pipe 2.

(5) Attachment of auxiliary plate 13 Each protrusion 14 of the auxiliary plate 13 is inserted into the covered pipe 11 and the auxiliary plate 13 is welded to the pile end plate 4.

(6) Centrifugal forming of the concrete layer 3 The concrete layer 3 in which the reinforcing bar 5 is embedded in the inner periphery of the steel pipe 2 is formed by centrifugal forming by supplying the concrete into the steel pipe 2 and rotating the steel pipe 2 at high speed.

Next, the SC pile pile head processing method will be described with reference to FIG.
FIG. 4A shows a state in which the SC pile is embedded in the ground by an embedded pile method such as a pre-boring method or an underground excavation method. After construction, the steel pipe 2 of the pile head 1 is cut along the circumferential direction as shown in FIG. Reference symbol C indicates a cutting line. The cutting position is the position of the partition plate 6 indicated by a in FIG. 1, more specifically, the position of the upper end surface of the partition plate 6.

  After cutting the steel pipe 2, as shown in FIG. 1C, a hanging tool 15 is attached to the upper end of the pile head 1, and the pile head upper part 1 a above the partition plate 6 is attached by the hanging tool 15 (FIG. 1). The pile head upper concrete layer 3a and the steel pipe 2 portion on the outer periphery thereof shown in FIG. Thereby, as shown to the same figure (d), the anchor reinforcement 7a of a pile head upper part side is exposed. In addition, although the concrete layer 3a has adhered to the partition plate 6, the concrete layer 3a peels from the partition plate 6 easily by lifting. If necessary, a release agent may be applied to the adhesion surface between the partition plate 6 and the concrete layer 3a.

  As described above, according to the present invention, the concrete bar of the pile head of the SC pile is embedded with the reinforcing rods having the partition plates and the anchor reinforcing bars that divide this into the pile head upper side and the pile head lower side, Since the anchor rebar on the upper side of the head is covered with the covering pipe, the anchor rebar can be exposed only by cutting the steel pipe in the circumferential direction and pulling out the upper portion of the pile head above the partition plate. Therefore, the axial cutting of the steel pipe, the crushing of the concrete layer, and the turning work are completely unnecessary, and the pile head processing work can be performed very easily.

  The above embodiment is merely an example, and the present invention can take various aspects. For example, the pile end plate 4 is generally an annular one in consideration of a joint pile. However, in the pile head to which the present invention is applied, the pile is not added, so it is not always necessary to have an annular shape, and it may be simply a disc-shaped one (blind plate). This also applies to the auxiliary plate 13.

DESCRIPTION OF SYMBOLS 1 Pile head 2 Steel pipe 3 Concrete layer 3a Pile head upper side concrete layer 3b Pile head lower side concrete layer 4 Pile end plate 5 Reinforcement rod 6 Partition plate 7 Anchor reinforcement 11 Covered pipe 13 Auxiliary plate 14 Protrusion

Claims (5)

SC pile having a cylindrical concrete layer on the inner periphery of the steel pipe and a pile end plate covering the end of the concrete layer at the pile head end,
Reinforcing bar is embedded in the concrete layer of the pile head,
This reinforcing bar is an annular partition plate whose outer periphery is fixed to the inner periphery of the steel pipe so as to partition the pile head concrete layer into the pile head upper side and the pile head lower side,
A plurality of anchor reinforcing bars extending to each of the pile head upper side concrete layer and the pile head lower side concrete layer are provided at intervals in the circumferential direction on this partition plate,
An anchor pile in the pile head upper concrete layer is covered with a covered pipe, and an upper end portion of the covered pipe is connected to the pile end plate.   The SC pile according to claim 1, wherein a plurality of holes are provided in the pile end plate at intervals in the circumferential direction, and upper ends of the respective coated pipes are inserted into these holes.   The auxiliary plate is fixed to the surface of the pile end plate, the auxiliary plate has a plurality of protrusions spaced apart in the circumferential direction, and each protrusion is inserted into the covering pipe. SC pile of description. Attaching a plurality of anchor reinforcing bars extending on both sides of the annular partition plate at intervals in the circumferential direction,
A process of covering a covered pipe on an anchor reinforcing bar on the upper side of the pile head;
Placing the rebar rod in a steel pipe, and fixing the outer periphery of the partition plate to the inner periphery of the steel pipe;
Fixing the pile end plate to the steel pipe end, and connecting the end of the covered pipe to the pile end plate;
A method for producing an SC pile, comprising: supplying concrete into the steel pipe and forming a concrete layer in which the reinforcing bar is embedded on the inner periphery of the steel pipe by centrifugal molding. It is a pile head processing method of SC pile according to any one of claims 1 to 3,
After burying the SC pile in the ground, the step of cutting the steel pipe in the circumferential direction at the partition plate position;
The pile head upper portion including the concrete layer above the pile head above the partition plate and the steel pipe portion on the outer periphery thereof is pulled out and removed, and the anchor rebar on the pile head upper side is exposed. SC pile head treatment method characterized by the above.

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