JP2001152447A - Method of building cage and winder for pc steel stranded wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent buckling and bending in the case of erection even in a cage having a large cross section and huge size, and to continuously conduct erection by continuously arranging a PC steel stranded wire, synchronized with erection speed. SOLUTION: In the erecting method, hoop reinforcements 11 are arranged at regular intervals among main reinforcements 1a, constituting the cage 1 and an intermediate reinforcement structure 12 as the precursor of the cage in which required sectional size is ensured is manufactured, and the intermediate reinforcement structure 12 is hung up and the PC steel stranded wires 10 are wound continuously on the outer circumferences of the main reinforcements 1a, erecting the structure 12 into an excavated pit 1 and synchronizing with the erection speed, and a hoop is manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for installing a reinforcing rod cage constituting an underground pillar cast in place and a device for winding a PC steel strand used for the method.

[0002]

2. Description of the Related Art As a procedure for constructing a cast-in-place underground pillar used for a wall foundation or the like, a method shown in FIG. 6 has conventionally been generally employed. In this method, first, as shown in (a), a reinforcing cage 1 having a predetermined length is assembled in an assembly yard, and then, as shown in (b), the reinforcing cage 1 assembled by using a crane truck 2 is muddy. In the borehole 3 filled with.

In the case of a deep underground pillar, since the length of the above-described reinforcing cage 1 is limited, as shown in FIG. Top hole 3
With the fixing jig 4 provided on the top of
The lower end of the rebar basket 1 ″ to be newly suspended is joined by welding or a mechanical joint structure, and after joining, the fixing jig is removed and the hanging operation is further repeated to reach a predetermined depth. Thereafter, concrete is poured into the excavation hole 3 using a tremy pipe (not shown) or the like, and is replaced with muddy water, whereby a reinforced concrete underground pillar is completed.

[0004]

In the above construction method, a general reinforcing bar cage 1 has a main reinforcing bar 1a and a large number of band bars 1b surrounding the main reinforcing bar 1a, as shown in FIG. 4 (a).
The vertical and horizontal cross section B × D is 1m
In the case of less than 10 mm, only the main reinforcing bar and the band reinforcing bar may be used, but in the case of a large cross section exceeding 1 m, reinforcement must be provided by arranging a plurality of intermediate band reinforcing bars 1 c vertically and horizontally.

[0005] For this reason, the self-weight of the rebar basket 1 to be manufactured becomes heavy, and if it is attempted to take a sufficient length to be built, FIG.
As shown in (a), by the starting load at the time of lifting,
The main rebar is plastically deformed, and buckling and bending are likely to occur.
Therefore, it is necessary to limit the dimensions and to perform the work of vertically connecting the reinforcing bar cages by suspending the erection work as described above, which is a factor of lowering the work efficiency.

By the way, the present inventors arrange the PC steel stranded wire 10 in place of the strip 1a even if the PC steel stranded wire has approximately five times the strength of the rebar and has the same sectional size. Thereby, as shown in FIG. 4B, attention was paid to the fact that the intermediate band reinforcing bar 1c can be omitted.

In arranging the PC stranded wire 10, a method of winding in synchronization with the hanging speed at the time of building the reinforcing bars is adopted. As shown in the figure, the reinforcing bars 11 are arranged at predetermined intervals between the main bars 1a, and the intermediate reinforcing bar structure 12 having only the cross-sectional dimensions is secured. Also, attention was paid to the fact that the starting load at the time of lifting was light and the bending moment was small.

The present invention has been made on the basis of the above-mentioned idea. The object of the present invention is to provide a steel cage having a large cross-section and a long dimension without buckling or bending at the time of starting up, and furthermore, the building is not erected. By arranging PC steel strands continuously in synchronization with the setting speed, continuous erection is performed, and a reinforcing cage basket with sufficient strength without intermediate band reinforcing bars and P
An object of the present invention is to provide an apparatus for winding a C steel strand.

[0009]

In order to achieve the above-mentioned object, the method of the present invention secures a required cross-sectional dimension by arranging the reinforcing bars at predetermined intervals between the main reinforcing bars constituting the reinforcing bar cage. And an intermediate reinforced structure that is the precursor of the reinforced cage,
While this intermediate reinforcing structure is lifted and built in the excavation hole, P
It is characterized in that a C steel strand is wound to form a band. Therefore, according to the method of the present invention, the intermediate rebar structure is lightweight, does not buckle or bend at the time of start-up even if it has sufficiently large dimensions, and has a sufficient rebar basket at the time of erection. Finished with strength.

[0010] Further, the apparatus of the present invention comprises a orbiting rail erected around an excavation hole, a bogie moving on the orbital rail, a turntable rotatably arranged on the bogie, and a rotatable on the turntable. And a drum that stocks a PC steel strand and feeds it toward the outer periphery of the intermediate reinforcing structure suspended in the excavation hole. Therefore, in the apparatus of the present invention, each time the bogie moves around, the PC steel strand is automatically and continuously wound around the outer periphery of the main reinforcement, and a high-strength streak is disposed on the outer periphery in the built-in state. Construct a reinforced basket.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Figure 1
Reference numeral 2 denotes a PC steel wire winding apparatus to which the method of the present invention is applied. In the drawings, the same parts as those in the related art are denoted by the same reference numerals, and only different parts will be described using different reference numerals. In the figure, excavation is performed at a predetermined aspect ratio,
A pair of orbiting rails 20 are provided around the drilling hole 3 filled with muddy water and surrounding the drilling hole 3 so as to surround the drilling hole 3.
Has been erected.

A carriage 22 travels on the orbiting rail 20 so as to be movable in one direction. The bogie 22 rotates the wheels 22a by driving a motor (not shown) disposed therein to orbit around the rail 20 at a predetermined speed in one direction. Further, on the turntable 24, a drum 28 stocking the PC steel stranded wire 10 is arranged. The drum 28 can be rolled via a roller bearing 30 or the like, and the drawn PC steel stranded wire 10 is set inside the bogie 22. Established wire guide 3
2 and is wound around the outer periphery of the intermediate reinforcing bar structure 12.

Accordingly, as shown in FIG. 3 (a), as a procedure for installing the rebar in which the above-mentioned winding device is disposed, the rebar 1 is provided at a predetermined interval between the main rebars 1a in the assembly yard.
1 is an intermediate reinforcing bar structure 1 in which only the cross-sectional dimensions are secured.
2 and then lifted by a crane truck 2 and suspended just above the excavation hole 3 as shown in FIG. In this state, the end of the PC steel strand 10 is fixed on the main reinforcing bar 1a of the intermediate reinforcing bar structure 12.

At the time of lifting from the assembled state, the bending moment is small as shown in FIG.
The length of the intermediate rebar structure can be increased by that much, and the labor for connecting the main rebar can be reduced.

In this state, by moving the bogie 22 around at a speed synchronized with the lowering operation of the hanging wire 2a of the crane truck 2, the PC steel strand 10 is wound with a winding interval proportional to the synchronous speed of the erection and the surrounding. And automatically and continuously wrapped around the outer periphery of the main reinforcing bar 1a. As shown in FIG. It will be built as basket 1. In this case, the drum 28 continuously turns the PC steel strand while rotating itself while constantly changing its direction in the tension direction of the PC strand by the turntable 24. Further, the intermediate reinforcing bar structure lifted by the crane truck 2 may be inserted into the excavation hole 3 by a temporary receiving device that can be slowly built with a hydraulic jack or the like.

As shown in the drawing, one or two workers are arranged to fix the PC stranded wire 10 to the main reinforcing bar 1a of the intermediate reinforcing steel structure 12 with a clip or the like at the time of winding.

[0017]

As is apparent from the above description, according to the method for installing a reinforcing rod cage according to the present invention, even when the reinforcing rod cage has a large cross section and a large size, it does not buckle or bend when starting up. In addition, by continuously arranging the PC steel strands in synchronization with the setting speed, the continuous setting is performed, and the strength is sufficient even without the intermediate band reinforcing bar.

Further, according to the apparatus for winding a PC steel stranded wire of the present invention, the winding of the PC steel stranded wire is automatically performed at the time of erection, so that the work is not interrupted.

[Brief description of the drawings]

FIG. 1 is a plan view showing an apparatus for winding a PC steel strand to which the method of the present invention is applied.

FIG. 2 is a sectional view taken along line AA of FIG.

FIGS. 3 (a) to 3 (c) are cross-sectional explanatory views showing a procedure for installing a reinforcing cage using the same device.

FIG. 4 (a) is a cross-sectional view of a conventional large-section reinforced cage, and FIG.
1 is a cross-sectional view of a rebar basket according to the present invention in the same cross section.

FIG. 5 (a) is an explanatory view showing a problem at the time of lifting a conventional reinforcing cage, and FIG. 5 (b) is an explanatory view showing a state at the time of lifting an intermediate reinforcing structure which is a precursor of the reinforcing cage of the present invention. is there.

6 (a) to 6 (c) are cross-sectional explanatory views showing a conventional reinforcing cage insertion procedure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reinforcing bar 1a Main bar 10 PC strand 11 Steel bar 12 Intermediate reinforcing bar 20 Rail 22 Dolly 28 Drum

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Koichi Tanaka 4-640 Shimoseito, Kiyose-shi, Tokyo F-term in Obayashi Corporation Technical Research Institute Co., Ltd. (Reference) 2D041 AA01 BA03 DA03 EB10 2E164 AA02 CA01 CA14 4E070 AA01 AB07 AC08 BA02 CA01

Claims (2)

[Claims] An intermediate reinforcing bar structure, which is a precursor of a reinforcing bar cage having a required cross-sectional dimension, is provided with a predetermined spacing between main bars constituting the reinforcing bar cage. Lifting an intermediate reinforcing bar structure and building it in a borehole, and continuously winding a PC steel stranded wire around the periphery of the main bar in synchronization with this build speed to form a reinforcing bar cage. Method. 2. A revolving rail erected around a borehole, a truck moving on the revolving rail, a turntable rotatably arranged on the bogie, and a PC steel rotatably arranged on the turntable. And a drum for stocking the stranded wire and extending toward an outer periphery of the intermediate reinforcing structure suspended in the borehole.
Steel stranded wire winding device.