JPH09177247A - Method for forming reinforcing bar cage in unit system for cast-in-site pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fabricate many types of steel bar cages for cast-in-site pile through combination of lesser sorts of cage units by fabricating cage units in shape of a circular arc previously at a factory, etc., thereby making effective the transport and site assembly works. SOLUTION: A reinforcing bar cage B composed of main bars 1 and hoops 2 is divided in three segments circumferentially so that cage units in the form of circular arc are fabricated previously at a factory, etc., and a number of such units are stacked and transported to the construction site. At the site, joint plates 5 furnished at the ends of hoop bars 2a in the form of circular arch are connected together by bolt and nut 6, and to maintain circular form, a band plate 4 is attached to the main bars 1 by means of welding, building, etc., so that a reinforcing bar cage B is completed. Further it is practicable to fabricate a reinforcing bar cage B having different pile diameter by combining the basic unit with another sort of the unit designed for a greater diameter. Thus the transport and site assembly works can be made effective, and the massproduction effect be achieved through common use of the units.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cast-in-place pile construction method, and more particularly to a method for streamlining the assembly and transportation of a reinforcing bar cage for cast-in-place pile.

[0002]

2. Description of the Related Art In the construction of cast-in-place piles on a narrow site in an urban area, it is difficult to assemble a reinforcing bar basket on site, so the reinforcing bar basket assembled at a factory is transported by truck and brought to the site. Often.

However, the rebar cage for cast-in-place piles is
Since it consists of multiple main bars and multiple circular bands that are wound around and fixed to their outer circumference, the volume is extremely large relative to the weight. However, the efficiency of truck transportation is poor. Especially 200
In the case of large diameter piles that exceed 0 mm, there is not enough room for the loading space, even though there is enough room for the loading capacity, so only one rebar cage can be loaded per large vehicle, resulting in high efficiency. Good transportation is impossible.

At a construction site where the site is sufficiently large and there is a sufficient space for material storage and rebar assembly work, it is common to carry in material rebar and assemble a rebar cage on site. However, since the number of connecting points by welding or the like between the main bar and the circular band bar per rebar cage is considerable, it takes a considerable time to assemble the rebar cage on site.

[0005]

SUMMARY OF THE INVENTION In view of the above-mentioned situation, the present invention provides a rebar cage unit conversion method for cast-in-place piles which can efficiently carry out truck transportation and field rebar cage assembling work and can significantly reduce costs. It is intended to provide the law.

[0006]

In order to solve the above-mentioned problems, in the present invention, a rebar cage unit having an arc shape as if the rebar cage for cast-in-place pile is divided into a plurality in the circumferential direction is produced, and this circle The arc-shaped rebar cage units are stacked in a compact state so that they can be transported. Then, after the rebar cage unit is carried into the site, the rebar cage units are integrated with each other to assemble the rebar cage. In each rebar cage unit, the main reinforcement and the arc-shaped divided reinforcement are fixed beforehand, so compared to the case where a circular reinforcement is wound around the outer periphery of the main reinforcement at the site, The basket assembly work will be reduced.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, a cast-in-place pile reinforcing bar cage composed of a plurality of main bars and a plurality of circular strips wound around and fixed to the outer circumference thereof is divided into a plurality of pieces in the circumferential direction. It can be carried out as a method for manufacturing cast-in-place pile reinforcing bar cage units in which a reinforcing bar cage unit having an arc shape is manufactured in advance in a factory or the like, and the reinforcing bar cage units are brought into the field, and then the reinforcing bar cage units are integrated to assemble the reinforcing bar cage. .

In this case, since the rebar cage units are arcuate, they can be stacked and transported in a compact state, the efficiency of truck transportation can be improved, and the transportation cost can be reduced. In addition, since it is possible to stack and store them in a compact state, it is possible to reduce the cost by mass-producing them in advance based on the demand forecast.

[0009] In particular, a plurality of stirrups curved in an arc shape,
A basic unit composed of a plurality of main bars fixed to the curved inner surface side of the stirrup, and a large-diameter unit in which the length of the arcuate stirrup is set longer than the basic unit and the number of main bars is increased. Can be prepared in advance, and by combining these units to form a reinforcing bar cage for cast-in-place piles with different pile diameters, a small number of units can handle multiple types of reinforcing bar cages with different pile diameters. Therefore, it is possible to further reduce costs by mass-producing shared units.

[0010]

An embodiment of the present invention will be described below with reference to the drawings. 1 to 6 show a reinforcing bar cage unit construction method for cast-in-place piles according to the present invention. This reinforcing bar cage unit construction method will be described below in the order of steps.

First, as shown in FIG. 1, a plurality of main bars 1
And a rebar cage unit A having an arc shape such that the rebar cage for cast-in-place piles, which is composed of a plurality of circular strips 2 wound around and fixed to the outer circumference thereof, is divided into three in the circumferential direction,
The required number is prepared in advance in a factory or in a work yard provided outside the construction site for cast-in-place piles. The main bar 1 and the arcuate bar 2a in each rebar cage unit A are connected to each other by means such as welding and binding.

Then, as shown in FIGS. 2 and 3, the rebar cage units A are stacked on the bed of the truck 3 in a multi-stage and compact state and loaded, and transported to a construction site of cast-in-place piles.

The rebar cage unit A carried into the construction site is placed sideways on an appropriate mount (not shown). Then, in this state, the rebar cage units A are integrated to assemble the rebar cage B as shown in FIGS. 4 and 6. Specifically, the three reinforcing bar cage units A are arranged so that the arcuate stirrups 2a form a circle, the ends of the arcuate stirrups 2a are connected to each other, and inside the main bar 1 group. For example, a band plate 4 formed by processing a flat bar into a circle is arranged, and the band plate 4 is fixed to the main bar 1 by means such as welding or binding to hold the rebar cage B in a circular shape.

Incidentally, it is desirable to shift the connecting position for each step so that the connecting positions of the end portions of the arcuate strip 2a do not overlap on a straight line in the axial direction. In this embodiment, as a means for connecting the ends of the arcuate stirrup 2a, the joint plates 5 having bolt holes are formed at both ends of the arcuate stirrup 2a at the time of producing the rebar cage unit A. The joint plates 5 are fixed to each other by means such as welding, and the adjacent joint plates 5 are connected to each other by bolts and nuts 6.

Reinforcing bar basket B assembled as described above
5 is hoisted by a lifting machine (not shown), is installed in the excavation hole 7 as shown in FIG. 5, and concrete 9 is placed in the hole by the tremie pipe 8 or the like to construct a cast-in-place pile.

As a means for holding the circular shape of the reinforcing bar cage B, the band plate 4 is used in the above-mentioned embodiment, but as shown in FIG. The circular shape of the rebar cage B may be retained. In this case, the reinforcement hoop muscle 10 may be welded to the main muscle 1, but may be connected by binding, or as shown in the figure, the reinforcement hoop muscle 10 may be formed by using a cross joiner 11 having a known structure. The main bar 1 may be connected.

According to the above construction, since the rebar cage unit A has an arc shape, as shown in FIG. 3, the rebar cage units A are stacked and loaded in a multi-stage and compact state on the loading platform of the truck 3. It is possible to efficiently carry out truck transportation and reduce transportation cost.

When assembling the reinforcing bar cage B by integrating the reinforcing bar cage units A at the site, the main bar 1 and the arcuate band 2a in each reinforcing bar cage unit A are connected to each other, so that the work at the site is Fewer, Rebar cage B
Can be assembled efficiently in a short time.

Further, since it is possible to stack and store the rebar cage units A in a compact state, it is possible to reduce the cost by mass-producing them in advance based on the demand forecast.

In the above embodiment, the joint plates 5 were connected to each other by a set of bolts and nuts 6, but as shown in FIG. 8, a plurality of sets of bolts and nuts 6 or U bolts and both ends thereof are screwed. The joint plates 5 may be connected to each other by mating nuts.

As means for fixing the joint plate 5 to the end of the arcuate band 2a, in addition to welding, as shown in FIG. 9, a sleeve 5a made of steel and continuously provided at the base end of the joint plate 5 is used. A crimp joint method of crimping the end portion of the arcuate band 2a or a filling joint method of filling the sleeve 5a with a filler 5b such as an adhesive as shown in FIG. 10 may be employed. When a threaded section reinforcing bar is used as the arcuate strip 2a instead of a normal deformed reinforcing bar, as shown in FIG. 11, at the base end of the joint plate 5, a long steel plate having a female screw formed on the inner surface is formed. A nut-shaped member 5c is continuously provided, and the long nut-shaped member 5c is screwed to a threaded joint of the arcuate band 2a, and a long nut-shaped member is formed by a lock nut 5d screwed prior to the threaded joint. A screw joint method of tightening the end surface of 5c to prevent loosening may be adopted. Although not shown, it is also possible to employ a combined joint method in which two appropriate kinds of methods are combined among the various methods described above.

Further, in each of the above embodiments, the arcuate strip 2
Although a method of connecting the joint plates 5 with each other by bolts has been shown as the connecting means between the a and the connecting means, the connecting means between the arcuate stirrups 2a is suitable as shown in FIG. Overlap margin a (for example, arcuate stirrup 2
Assuming that the diameter of a is d, a lap joint method having 35d to 40d) or an applicable welding length b as shown in FIG.
(For example, a welding joint system for performing flare arc welding of 10d), or as shown in FIGS.
You may employ | adopt the wedge joint system comprised from the joint main body 12 which fits in the end part of a, and the wedge 13.

In adopting the above-mentioned wedge joint method, as shown in FIGS. 16 to 17, the first member having an opening on the inner surface for fitting the joint main body 12 to the arcuate band 2a from its curved outer surface side. 12a, a second member 12b having an outer surface opened to be fitted from the curved inner surface side, and those 12a, 12
If a wedge joint composed of b and a wedge 13 that fixes the arcuate stirrup 2a, 2a is used, the fitting of the joint body 12 to the end of the arcuate stirrup 2a is easy, and connection work is easy. Is.

As means for connecting the arcuate stirrups 2a other than the above, as shown in FIG. 19, ring-shaped portions 2b are preliminarily bent at both ends of the arcuate stirrups 2a, and each rebar cage unit. Each of the main bars 1 is attached to the ring-shaped portion 2b in A.
Insert one by one, and connect the stirrup part c located close between the ring-shaped parts 2b, 2b of the adjacent rebar cage units A by any one of the lap joint method, the weld joint method, and the wedge joint method. You may do it. FIG.
As shown in 0, even if the ring-shaped portions 2b of the adjacent rebar cage units A are overlapped with each other, the common main bar 1 is inserted thereinto, and the main bar 1 connects the arcuate stirrups 2a to each other. Good.

21 to 23 show another embodiment of the present invention. In this embodiment, as a reinforcing bar cage unit A, a plurality of arcuate stirrups 2a curved in an arc shape and a plurality of main bars 1 fixed to the curved inner surface side of the arcuate stirrup 2a are provided. A basic unit A ₁ and a basic unit A, each of which has a size obtained by dividing the rebar cage B corresponding to a certain pile diameter into three in the circumferential direction.
₁ set long the length of the arc-shaped strip muscle 2a than and main reinforcement 1
A large diameter unit A ₂ having an increased number is produced in advance, and a combination of these units A ₁ and A ₂ is used to produce a reinforcing bar cage B corresponding to cast-in-place piles having different pile diameters. It has a feature. Reference numeral 2c in FIG. 23 indicates a connecting portion between the arcuate stirrups 2a.

Since the basic unit A ₁ and the large diameter unit A ₂ have the same curvature, two basic units A ₁ and one large diameter unit A ₂ are provided as shown in FIG. When assembling a rebar cage B having a diameter larger than that of the rebar cage assembled from the three basic units A _{1 in} combination, the rebar cage B does not have a circular shape as it is, but these units A ₁ and A ₂ each have an arc shape. Therefore, the arcuate stirrup 2
The deformation of a is easy. Therefore, as shown in FIG.
A circular (perfect circle) rebar cage B is formed by deforming the arcuate band 2a of the large-diameter unit A _{2 along} the band plate 4 or the reinforcing hoop bar 10 arranged inside the main bar 1 group. Is obtained.

According to this embodiment, since the basic unit A ₁ is shared by the small diameter rebar cage B and the large diameter rebar cage B,
Further cost reduction is possible by mass production of the basic unit A ₁ .

More specifically, for example, when the basic unit A ₁ has a size of a reinforcing bar basket B corresponding to a cast-in-place pile diameter of 1400 mm divided into three, as shown in Table 1, a unit for large diameter is used. as a a ₂ that increasing the main reinforcement number corresponds to 314mm extended and extension than the arc-shaped girdle muscular 2a of the base unit a ₁ an arcuate girdle muscular 2a, similarly 628mm extended arcuate girdle muscular 2a Done A ₃ and 94
2 mm extended A ₄ is prepared in advance, and these 4 types of units A ₁ , A ₂ , A ₃ , and A ₄ are combined as shown in Table 2 to obtain 1400 mm to 2 mm.
It is possible to assemble 10 types of rebar cage B corresponding to a pile diameter of 300 mm.

Thus, the basic unit A ₁ and the large-diameter units A ₂ , A ₃ , A in which the length of the arcuate band 2a is set longer than that of the basic unit A ₁ and the number of main bars is increased.
₄ and previously prepared, these units A ₁ , A ₂ ,
By constructing the reinforcing bar basket B corresponding to the cast-in-place piles having different pile diameters by combining A ₃ and A ₄ ,
A small number of units can support various types of rebar cages with different pile diameters, and further cost reduction can be achieved by mass production of shared units.

[0030]

[Table 1]

[0031]

[Table 2]

In each of the above embodiments, the rebar cage unit A (A ₁ , A ₂ , A ₃ , A ₄ ) having a shape obtained by dividing the rebar cage into three parts is used. The present invention should not be limited to this, and for example, the rebar cage unit A may be embodied in an arc shape such as a bisector divided into two or an arc shape such as divided into four or more. Is.

[0033]

According to the present invention, which has the above-described structure, it is possible to efficiently carry out the rebar cage assembling work in trucks and on-site and mass-produce it on the basis of the demand forecast. There is an effect that the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory view of a reinforcing bar cage unit in a method for forming a reinforcing bar cage unit for a cast-in-place pile according to the present invention.

FIG. 2 is a side view of the rebar cage unit during truck transportation.

FIG. 3 is a rear view of the reinforcing bar cage unit during transportation by truck.

FIG. 4 is a configuration explanatory view of a reinforcing bar cage in which the above reinforcing bar cage units are integrated and assembled.

FIG. 5 is a vertical cross-sectional side view showing a state in which the reinforcing bar cage is built in an excavation hole and concrete is poured.

FIG. 6 is an explanatory view of a connecting means for connecting the arcuate stirrups in the rebar cage.

FIG. 7 is a perspective view showing an example of a connecting means for connecting a main bar of a reinforcing bar cage and a reinforcing hoop bar arranged inside the main bar.

FIG. 8 is an explanatory view of another connecting means for connecting the arcuate stirrups.

FIG. 9 is an explanatory view of another connecting means for connecting the arcuate stirrups.

FIG. 10 is an explanatory view of another connecting means for connecting arcuate stirrups.

FIG. 11 is an explanatory view of another connecting means for connecting arcuate stirrups.

FIG. 12 is an explanatory view of another connecting means for connecting the arcuate stirrups.

FIG. 13 is an explanatory view of another connecting means for connecting arcuate stirrups.

FIG. 14 is an explanatory view of another connecting means for connecting arcuate stirrups.

FIG. 15 is a vertical cross-sectional side view of a main part of the connecting means of FIG.

FIG. 16 is an explanatory view of another connecting means for connecting arcuate stirrups.

FIG. 17 is a vertical cross-sectional side view of an essential part for explaining the connecting means of FIG.

FIG. 18 is a vertical cross-sectional side view of essential parts for explaining the connecting means of FIG. 16;

FIG. 19 is an explanatory view of another connecting means for connecting the arcuate stirrups.

FIG. 20 is an explanatory view of another connecting means for connecting arcuate stirrups.

FIG. 21 is an explanatory view of a basic unit and a large diameter unit showing another embodiment of the present invention.

FIG. 22 is an explanatory diagram of the basic unit and the large diameter unit.

FIG. 23 is a configuration explanatory diagram of a reinforcing bar cage having different diameters configured by combining the basic unit and the large diameter unit.

[Explanation of symbols]

A ... Rebar cage unit, A ₁ ... Basic unit, A ₂ ,
A _3, A ₄ ... thick diameter contouring unit, B ... reinforcing bar cage, 1 ... main reinforcement,
2a ... Arc strip.

Claims (2)

[Claims] 1. A rebar cage having a circular arc shape, such as a rebar cage for cast-in-place piles, which is composed of a plurality of main rebars and a plurality of circular strips wound around and fixed to the outer periphery of the rebar cage. A method for manufacturing a reinforcing bar cage unit for cast-in-place piles, which is characterized in that the reinforcing bar cage unit is manufactured in advance in a factory or the like, the reinforcing bar cage unit is brought to the site, and then the reinforcing bar cage units are integrated to assemble the reinforcing bar cage. 2. A basic unit composed of a plurality of arcuate stirrups and a plurality of main bars fixed to the curved inner surface side of the stirrup, and an arcuate stirrup than the basic unit. A large-diameter unit with a long length set and an increased number of main bars was prepared in advance, and by combining these units, a reinforcing bar cage corresponding to cast-in-place piles with different pile diameters was constructed. The cast-in-place pile reinforcing bar cage unit construction method according to claim 1.