JPH0416308A - Manufacture of extra-high flexurally tough pc pile - Google Patents

Abstract

PURPOSE:To economically manufacture an extra-high flexurally tough PC pile with small labor by a method wherein longitudinal reinforcing bars are connected with a transverse retaining reinforcing bar under the condition being brought into contact with its inside by means of connectors between longitudinal and transverse reinforcing bars, each of which has an attached side engaging position and a detached side engaging position, and, after that, by tensing the longitudinal reinforcing bars in a concrete form, the transverse restraining reinforcing bar is positioned outside the longitudinal reinforcing bars. CONSTITUTION:At the coiled part side end of the longitudinal reinforcing bar inserting part 13 of each connector 12 between longitudinal and transverse reinforcing bars interposed between a transverse restraining reinforcing bar 11 and longitudinal reinforcing bars 10, an attached side engaging part 16a, which positions the longitudinal reinforcing bars 10 to positions contacting with the transverse restraining reinforcing bar 11, is provided, while, at its other end, a detached side engaging part 16b is provided. By inserting the longitudinal reinforcing bars 10 in the attached side engaging parts 16b, abutting the transverse restraining reinforcing bar 11 against the outside of the longitudinal reinforcing bars 10 and coiling the coiled parts 15 round the outside of the bar 11, the bars 10 and 11 are connected with each other so as to be assembled in the form of a cylinder.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides ultra-high bending toughness P for use in civil engineering and building foundations.
This invention relates to a method for manufacturing C piles.

(Prior art) Conventionally, the manufacture of prestressed concrete piles, in which prestressed concrete piles are made by burying prestressed concrete steel in the vertical direction and applying prestress in the vertical direction, have been carried out using a cylindrical formwork, and by centrifugal force. A centrifugal molding method that molds into hollow knot shapes is common.

This conventional method uses a knitting machine to create a press l.
- A group of vertical reinforcements made of PC steel wire 11 for imparting stress is arranged in a cylindrical shape, and hoop reinforcements 2 are arranged in a spiral shape on this,
Alternatively, by winding and welding a large number of rings, it is knitted into a cylindrical cage shape (Fig. 9A), which is then cut in half and inserted into the lower half with the upper half of the cylindrical form 3 removed. , each Pcm wire 1.1...
4 and fix it to the tension support fitting 5 (
Figure 9B).

After filling a predetermined amount of concrete 6 in this state, the upper half of the cylindrical formwork 3 is covered and fixed, and one tension-bearing metal fitting 5
is pulled by a jack to apply a predetermined tension force to the PCa wire, and the reaction force is supported at both ends of the cylindrical form 3 (FIG. 9C). Also, before filling the concrete 6, the cylindrical form 3 is
The upper half of the wire is covered and fixed, and the tension-bearing metal fitting 5 is pulled with a jack to apply a predetermined tension to the PCA wire, and then concrete is filled with a pump. In this state, the cylindrical form 3 is placed on the rotating roller 7 of the centrifugal molding machine, rotated,
The concrete 6 is formed into a cylindrical shape along the inner surface of the form by centrifugal force (Fig. 9 D), and then placed in a curing chamber whose temperature is controlled by steam etc. After curing, the tension bearing fittings 5 are removed and the tension is applied. By solving this, prestress is introduced into the concrete.2 Conventional PC piles manufactured in this way can be used to increase the bending fracture strength by increasing the amount of prestress introduced, or to increase the flexural fracture strength during an earthquake. In order to increase seismic resistance, it is important to increase the plastic deformation capacity at the same time as increasing the bending fracture resistance.Increasing the prestress reduces the plastic deformation capacity, which actually reduces the seismic performance. .

In view of these problems, in order to improve seismic performance, the present inventor buried spiral horizontal restraining reinforcement between the cylindrical longitudinal reinforcement group and the outer peripheral surface of the pile, and By using longitudinal reinforcing bars, we have developed ultra-high toughness PC piles with high bending fracture strength and high plastic deformation capacity.

(Problem to be solved by the invention) The ultra-high toughness PC pile as described above has a high yield strength of the longitudinal reinforcement group and a high
In order to maintain properties such as elongation rate, it is not preferable to knit by spot welding used in active manufacturing.
In order to enhance the bending toughness improvement effect of the transverse restraint reinforcement, it is necessary to arrange the transverse restraint reinforcement as close to the outer circumferential surface of the pile as possible while keeping it away from the longitudinal reinforcement group. The muscle is
It was necessary to position it strongly to withstand centrifugal molding.

However, until now, a manufacturing method suitable for manufacturing such ultra-high toughness PC piles has not yet been developed.

Therefore, the present inventor developed a p
By arranging the cH line group outside and parallel to the longitudinal reinforcement group in a cylindrical shape, and keeping the longitudinal reinforcement group under tension during concrete molding, the horizontal restraining reinforcement can be positioned at a predetermined position. (Patent application No. 1-143)
No. 006).

However, this method involves tensing and burying vertical 20w4 wires in addition to the longitudinal reinforcing bars that mainly apply prestress in the line direction, resulting in high costs and requiring a lot of labor for reinforcing. There was a problem.

In view of this situation, the present invention aims to provide a method for manufacturing the above-mentioned ultra-high toughness PC piles economically with less labor.

(Means for Achieving the Object) A feature of the method for manufacturing an ultra-high toughness PC pile according to the present invention for achieving the above-mentioned objects is that a spiral structure made of PCIIl+11 is formed near the outer peripheral surface of a cylindrical concrete pile. When manufacturing an ultra-high toughness PC pile, in which horizontal restraint bars are arranged, and a plurality of longitudinal bars are arranged in a cylindrical shape at intervals inside the horizontal restraint bars and directed in the longitudinal direction of the pile, the lateral restraints are an approaching side locking part that locks the vertical reinforcement at a position in contact with the reinforcement; and a remote side locking part that locks the vertical reinforcement at a position that is a predetermined distance away from the horizontal restraining reinforcement toward the center of the pile. A cylindrical PC steel wire cage is formed by assembling the vertical bars close to the horizontal restraining bars via a longitudinal and transverse bar connector having a longitudinal and transverse bar connector, and then the PC steel wire cage is assembled for centrifugal forming. The vertical bars are housed in a cylindrical form, and by positioning both ends of each vertical bar at the required buried position and applying tension, the vertical bars are moved to the locking part on the remote side of the #l transverse bar connector and placed in a predetermined position. At the same time, the transverse restraint bars are positioned at predetermined positions via the longitudinal and transverse bar connectors.

(Function) In this method, each vertical reinforcement is assembled in a fixed state close to the inside of the PC steel wire cage or spiral horizontal restraining reinforcement, and it is stored, transported, etc. in this state. When it is housed in a molding frame, both ends of the vertical reinforcement are positioned at predetermined positions, and tensioned by jacking, the entire vertical reinforcement moves toward the center and is moved to a position away from the transverse restraining reinforcement. The lateral restraints are positioned on the outside of the lateral restraints via four lateral connectors.

In this way, by positioning the vertical reinforcement and horizontal restraining reinforcement, and centrifugally forming the concrete with it filled in the formwork, the concrete moves to the inside of the formwork to a uniform thickness, and each node is buried. It is formed into a cylindrical shape.

(Example) Next, an example of the implementation of the present invention will be described with reference to FIGS. 1 to 8.

FIGS. 1 and 2 show an example of a PC pile manufactured by the method of the present invention. This PC pile has a cylindrical shape, and has a vertical reinforcement group 10A in which vertical reinforcements 10, 10, . On the outside of the PC pile, horizontal restraining bars 11 are buried in a spiral arrangement near the outer peripheral surface of the PC pile and oriented in the circumferential direction. These horizontal restraining muscles 11 and vertical muscles 10
, 10, . . ., width transverse reinforcement connectors 12, 12, . . ., which also serve as spacers, are interposed.

Next, the manufacturing method will be explained. First, the vertical stripes 10.
10..., lateral restraint bars 11 and longitudinal and transverse bar connectors 12
．． A PC steel wire cage 13 composed of 12... is formed. This PC steel III! Forming No. 13 can be performed by modifying a conventionally used reinforcing bar knitting machine. That is, as shown in FIG.
0, 10, etc. are made parallel to each other, extruded sequentially in the longitudinal direction into a cylindrical arrangement, and sequentially sends out the horizontal restraint bars 11 of a spiral cylinder formed into the required diameter by contacting the outside thereof. Vertical stripes 10, 10...
... and the lateral restraint muscle 11 with the Mx lateral connector 12.12.
・・・・Fix it with vertical stripes 10, 1 in the direction of the center line.
0..., and in the circumferential direction, the horizontal restraint muscle 1
Made of PC steel wire RA13 regulated by 1.

Note that each of the vertical bars 10, 10, . . . is cut in advance to a required length, and male threads 10a are formed at both ends.

As shown in FIGS. 4 to 6, the longitudinal and transverse reinforcement connectors are entirely formed by bending and forming steel wires, and have main parts 15, 15 for wrapping around a pair of lateral restraining reinforcements at one end. , Continuing from this, an elongated link-shaped longitudinal reinforcement insertion portion 16 is formed.

An approach-side locking portion 16a for positioning the longitudinal reinforcement 10 at a position in contact with the transverse restraint muscle 11 is formed at the end of the tendril side of the longitudinal reinforcement insertion portion 16, and the other end is formed as a separation-side locking portion. 16
b. The approach side locking part 16a is the longitudinal strip insertion part 1
The vertical strip 10 inserted in contact with the tendril side end of 6 is the curved part 1
It is designed to be held and locked by 6c,
Separation 11 by applying a force above a certain level to the longitudinal strip 10
! 1 to the locking portion 16b side.

As shown in FIGS. 7 and 8, the longitudinal and transverse reinforcement connectors 12 are arranged at an angle of about 90° to the tendril side end of the elongated ring-shaped longitudinal reinforcement insertion portion 16.
The approach-side locking portion 16a may be formed by twisting it to a certain extent.

PCfJ by the transverse muscle connector 12 configured in this way
A line! 13 is assembled by inserting the vertical reinforcement 10 into the approach-side locking portion 16a as shown by the solid line in FIGS. ,15
By wrapping it around the outside, the two muscles are connected and assembled into a cylindrical shape.

PC steel wire assembled in this way! ! 13 into the formwork 20 for centrifugal molding, and as shown in FIGS. . . . by bending both ends toward the center and inserting them into the respective through holes of the pair of tension bearing fittings 22, 22,
On the outside thereof, screw the fixing nut 23 into the male screws Oa at both ends. Then, the - side tension bearing fitting 22 is supported at the end of the formwork 2o, and the other tension bearing fitting 22 is movably inserted into the formwork 20, and the tension rod 24 is connected to the center thereof. Then, the fixing plate 25 is fitted onto the male screw 24a formed outside the rod 24, and the fixing plate 25 is supported by the end of the formwork 20.

After completing the reinforcement arrangement in this way, a Jatu'r (not shown) is set at the end of the formwork 2°, and one tension bearing fitting 22 is pulled through the rod 24, and the longitudinal reinforcement 10 make me nervous. As a result, a tensile force for prestressing is applied to the longitudinal reinforcement 1o, and this tension acts on the longitudinal reinforcement 10 in the direction of straightening it, thereby acting in a direction away from the transverse restraint reinforcement 11, as shown in FIG. As shown by the phantom lines in FIG. 6, the longitudinal and transverse reinforcement connectors 12 are disengaged from the approach side locking portion 16a, move to the remote side diameter portion 16b, and are connected to the transverse restraint bars 11 via the longitudinal and transverse connectors 12. positioned in position.

After the tension is applied in this way, the fixing plate 25 is rotated and moved until the surface around it comes into contact with the end surface of the formwork 20, and then the tension due to the jacking is released and the end of the formwork 20 is Apply reaction force and remove the jack.

Next, the necessary amount of comfort 26 is placed in the formwork 20 by a conventional method.
Filled with water, molded into a round shape using a centrifugal molding machine, and removed from the mold after the necessary curing treatment.

(Effects of the Invention) As described above, in the method for manufacturing an ultra-high bending toughness PC pile of the present invention, a transverse reinforcement connecting device having an approach-side locking position and a remote-side locking position is connected to the inside of a lateral restraint reinforcement. By connecting the vertical bars in this state, positioning both ends of the vertical bars in a predetermined position within the molding frame and applying tension, the vertical bars will move to a predetermined position, and horizontal bars will be placed at intervals on the outside of the vertical bars. By positioning via restraint bars or longitudinal and transverse bar connectors,
When transporting and storing CamH, mounting plates must be placed in a stable condition, and this can be done automatically by accurate positioning of horizontal restraining bars within the formwork or tensioning of vertical bars, resulting in high performance. This makes it possible to manufacture PC piles at low cost and with good workability.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of an example of a PC pile manufacturing state according to the present invention, Fig. 2 is a cross-sectional view taken along line A-A in Fig. 1, and Fig. 3 is an example of assembly of a pca@ cage used in the present invention. A side view, FIG. 4 is a front view of an example of a longitudinal and transverse bar connection device, FIG. 5 is a front view of a state of connection by the same coupling device, FIG. 6 is a side view of the same, and FIG. 7 is another example of a longitudinal and transverse bar connection. 8 is a front view of the same, FIG. 9 is a side view of the same, and FIGS.
(D) is a manufacturing process diagram showing a typical example of a conventional manufacturing method. 0... Vertical stripe, 10a... Male thread, 1.
... Lateral restraint muscle, 12... Longitudinal and transverse muscle connector,
3...PC@wire basket, 14...Rebar knitting machine, 5...Main part, 16...Joint tube insertion part, 6a... ...Approaching side locking part, 6b...Releasing side locking part, 0...Formwork, 21...End iron plate, 2...
...Tension bearing fitting, 23... Fixing nut,
4... Rod, 25... Fixing plate, 6...
·····concrete. Base 5 Figure 6

Claims (1)

[Claims] A spiral horizontal restraint bar made of PC steel wire is placed near the outer circumferential surface of a cylindrical concrete pile, and a plurality of longitudinal bars are placed inside the horizontal restraint bar at intervals and oriented in the longitudinal direction of the pile. When manufacturing an ultra-high bending toughness PC pile arranged in a shape, an approach side locking part that locks the vertical reinforcement at a position in contact with the horizontal restraint reinforcement, and a predetermined length from the horizontal restraint reinforcement toward the pile center side. A cylindrical PC steel wire is assembled by assembling the vertical reinforcement in a state in which the vertical reinforcement is brought close to the horizontal restraining reinforcement through a longitudinal and transversal reinforcement connector having a remote side locking portion that locks the vertical reinforcement at a distant position. A cage is formed, the PC steel wire cage is housed in a cylindrical form for centrifugal forming, and both ends of each vertical bar are positioned at the required buried position and tensioned to form the longitudinal bar and the longitudinal bar. Manufacture of an ultra-high bending toughness PC pile, characterized in that it is moved to a distant side locking part of a connecting device and placed in a predetermined position, and the transverse restraining reinforcement is positioned at a prescribed position via the longitudinal and transverse reinforcement connecting device. Method.