JP2021014721A - Reinforcement bar joint method and reinforcement bar joint structure - Google Patents

Abstract

To provide a reinforcement bar joint method and a reinforcement bar joint structure capable of eliminating overcrowinding arrangement of reinforcement bars at a joint part with a pile and a beam, or a footing foundation.SOLUTION: A reinforcement bar joint method of the present invention is a joint method of a joint where a large number of reinforcement bars 11 aligned on a circle of a pile head of a pile viewing from an upper surface and a plurality of inserting reinforcement bars 13 extending upward above the reinforcement bars are jointed, wherein the joint of the plurality of reinforcement bars and the inserting reinforcement bars are connected by passing a part of the reinforcement bars among the plurality of reinforcement bars adjacent to each other in a large number of reinforcement bars adjacent through a first joint member 1 and fixing the other part of the reinforcement bars on the first joint member 1, fixing the part of the reinforcement bars on a second joint member 2, and fixing the inserting bars in the second joint member 2.SELECTED DRAWING: Figure 2

Description

The present invention relates to a reinforcing bar connecting method and a reinforcing bar connecting structure at a pile head of a pile.

Examples of conventional cast-in-place piles are shown in FIGS. 1 (a) to 1 (c). This example is a construction method using a casing. As shown in the figure, in the cast-in-place pile 90, a reinforcing bar cage 92 composed of a large number of reinforcing bars extending in the direction of the pile axis and a ring-shaped shear reinforcing bar is housed in the casing 91, and concrete 93 is cast in the casing 91. In the pile head 94, the upper portions 92a of a large number of reinforcing bars are inserted into the main reinforcing bars b1 of the beam B to form a joint with the beam B. The casing 91 is pulled out and removed after the concrete is placed.

Patent Document 1 includes a pile body composed of a plurality of main reinforcing bars and concrete arranged in the axial direction, and a connecting material for connecting the main reinforcing bars at an arbitrary position orthogonal to the axial direction of the pile body. The end of the first main reinforcing bar arranged in one direction with the connecting material as a boundary is fixed to the connecting material and is arranged on the opposite side to the first main reinforcing bar. Disclosed is a seismic pile characterized in that the end portion of the second main reinforcing bar is attached to the connecting member so as to be stretchable in the axial direction (claim 1).

Japanese Unexamined Patent Publication No. 2000-328563

Since a large number of reinforcing bars 92a and b1 intersect at the joint with the beam B at the pile head 94 of the conventional cast-in-place pile 90 of FIGS. 1 (a) to 1 (c), the reinforcement arrangement at the joint becomes overcrowded. Due to such overcrowding, the number of reinforcing bars constituting the reinforcing bar cage of the pile is large, so that there is a problem that when the reinforcing bars intersect with the main reinforcing bars such as beams, they often interfere with each other.

Further, although the pile structure of Patent Document 1 includes a connecting material for connecting reinforcing bars, it does not disclose measures against overcrowded reinforcing bars.

In view of the above-mentioned problems of the prior art, an object of the present invention is to provide a reinforcing bar connecting method and a reinforcing bar connecting structure capable of eliminating overcrowding at a joint between a pile and a beam or a footing foundation.

The reinforcing bar connecting method for achieving the above object is a connecting method of a large number of reinforcing bars arranged on the circumference when viewed from the upper surface at the pile head of the pile and a plurality of inserting reinforcing bars extending above the reinforcing bars. A part of the plurality of adjacent reinforcing bars of the large number of reinforcing bars is passed through the first connecting member, the remaining reinforcing bars are fixed to the first connecting member, and the part of the reinforcing bars is connected to the second connecting member. By fixing to the connecting member and fixing the insertion reinforcing bar to the second connecting member, the plurality of reinforcing bars and the insertion reinforcing bar are connected.

According to this reinforcing bar connecting method, a part of the reinforcing bars of the plurality of adjacent reinforcing bars among the many reinforcing bars arranged on the circumference at the pile head is passed through the first connecting member, and the remaining reinforcing bars are passed through. By fixing to the first connecting member and fixing some of the reinforcing bars to the second connecting member, it is possible to connect the plurality of adjacent reinforcing bars to the first connecting member and the second connecting member, and further, the second The insertion reinforcing bars are fixed to the connecting members of the above, and the number of such insertion reinforcing bars can be less than the number of a plurality of reinforcing bars connected to the first and second connecting members. That is, by passing through the first connecting member and the second connecting member, it is possible to connect a plurality of adjacent reinforcing bars and a smaller number of inserted reinforcing bars than the plurality of reinforcing bars. In this way, the number of inserted reinforcing bars can be reduced compared to the number of reinforcing bars lined up on the circumference at the pile head, so that overcrowding at the joint between the pile and the beam or footing foundation can be eliminated. be able to.

In the above-mentioned reinforcing bar connecting method, the plurality of adjacent reinforcing bars are at least three reinforcing bars, two reinforcing bars at both ends of the at least three reinforcing bars are passed through the first connecting member, and the remaining at least one. It is preferable to fix the reinforcing bar of the book to the first connecting member. In this case, the two reinforcing bars at both ends that penetrate the first connecting member are fixed to the second connecting member.

Further, the first connecting member and the second connecting member can be arranged so that the upper surface of the first connecting member and the lower surface of the second connecting member are in contact with each other. The first or second connecting member has a recessed portion so as to accommodate the upper portion of the remaining reinforcing bar protruding from the first connecting member, and the first or first connecting member has a surface other than the recessed portion. It can be brought into contact with the connecting member of 2.

Further, the insertion reinforcing bar can be screwed into the threaded portion of the second connecting member to be fixed.

Further, the insertion reinforcing bar may be passed through the hole provided in the second connecting member and fixed with a nut.

Further, it is preferable that the first connecting member and the second connecting member are arranged concentrically with respect to a large number of reinforcing bars arranged on the circumference and all around the circumference. In this case, the number of the inserted reinforcing bars and the fixed position of the inserted reinforcing bars in the second connecting member are such that the inserted reinforcing bars do not interfere with a plurality of main bars of the beam or footing foundation arranged at the pile head. It is preferable to set.

The reinforcing bar connecting structure for achieving the above object is a connecting structure of a large number of reinforcing bars arranged on the circumference when viewed from the upper surface at the pile head of the pile and a plurality of inserting reinforcing bars extending above the reinforcing bars. A part of the plurality of adjacent reinforcing bars of the large number of reinforcing bars penetrates the first connecting member, the remaining reinforcing bars are fixed to the first connecting member, and the part of the reinforcing bars is further second. The plurality of reinforcing bars and the inserted reinforcing bars are connected by being fixed through the connecting member of the above and the insertion reinforcing bars being fixed to the second connecting member.

According to this reinforcing bar connecting structure, a part of the reinforcing bars of the plurality of adjacent reinforcing bars among the many reinforcing bars arranged on the circumference at the pile head is penetrated through the first connecting member, and the remaining reinforcing bars are passed through. By fixing to the first connecting member and fixing some of the reinforcing bars to the second connecting member, it is possible to connect the plurality of adjacent reinforcing bars to the first connecting member and the second connecting member, and further, the second The insertion reinforcing bars are fixed to the connecting members of the above, and the number of such insertion reinforcing bars can be less than the number of a plurality of reinforcing bars connected to the first and second connecting members. That is, by passing through the first connecting member and the second connecting member, it is possible to connect a plurality of adjacent reinforcing bars and a smaller number of inserted reinforcing bars than the plurality of reinforcing bars. In this way, the number of inserted reinforcing bars can be reduced compared to the number of reinforcing bars lined up on the circumference at the pile head, so that overcrowding at the joint between the pile and the beam or footing foundation can be eliminated. be able to.

According to the reinforcing bar connecting method and the reinforcing bar connecting structure of the present invention, the number of inserted reinforcing bars at the joint between the pile and the beam or the footing foundation can be reduced at the pile head, so that the joint between the pile and the beam or the footing foundation can be reduced. It is possible to eliminate the overcrowded reinforcing bars in.

It is a main part side view (a), the top view (b), and the main part perspective view (c) which show schematic structure example of the conventional cast-in-place pile. In the present embodiment, a perspective view (a) showing a connecting state of a large number of reinforcing bars of the reinforcing bar cage with the first connecting member and the second connecting member, and a state in which the inserted reinforcing bars are further fixed to the second connecting member are shown. It is a perspective view (b) which shows. It is a main part perspective view (a)-(d) for demonstrating the connection process by the 1st and 2nd connection members in this embodiment. It is a main part perspective view which shows another connection example by this embodiment. It is the main part top view (a) and the main part side view (b) which outlines the joint part with the beam in the pile head by this embodiment.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. FIG. 2 is a perspective view (a) showing a connection state between a large number of reinforcing bars of the reinforcing bar cage, the first connecting member, and the second connecting member in the present embodiment, and further, the inserted reinforcing bar is used as the second connecting member. It is a perspective view (b) which shows the fixed state. FIG. 3 is a perspective view (a) to (d) of a main part for explaining a connecting process by the first and second connecting members in the present embodiment.

The reinforcing bar cages 10 shown in FIGS. 2 (a) and 2 (b) are a large number of reinforcing bars 11 extending in the pile axis direction and arranged at equal intervals on the circumference when viewed from the upper surface, and a large number of reinforcing bars 11 at predetermined intervals in the pile axis direction. It is composed of a ring-shaped shear reinforcing bar 12 arranged so as to surround the reinforcing bar 11 for cast-in-place piles, and the upper portion thereof corresponds to a pile head.

A plurality of first connecting members 1 are arranged on the upper portion of the reinforcing bar car 10, and the same number of second connecting members 2 are arranged on the first connecting members 1. The plurality of connecting members 1 and 2 are arranged in an annular shape in contact with each other on the circumference so as to form one circle each. Therefore, each of the connecting members 1 and 2 is formed in an arc shape when viewed from the upper surface, and is configured in a substantially block shape when viewed as a whole.

As shown in FIGS. 2A and 2B, a part of the plurality of adjacent reinforcing bars among the large number of reinforcing bars 11 is passed through each first connecting member 1, and the remaining reinforcing bars are passed through the first connecting member 1. It is fixed to the connecting member 1, and a part of the reinforcing bars penetrating the first connecting member 1 is further penetrated and fixed to each of the second connecting members 2, and the inserted reinforcing bar 13 is further fixed to the second connecting member 2. By doing so, the plurality of reinforcing bars 11 and the inserted reinforcing bars 13 are connected. The diameter of the insertion reinforcing bar 13 is larger than the diameter of the reinforcing bar 11.

The process of connecting the reinforcing bar of the reinforcing bar cage and the inserting reinforcing bar via the first connecting member and the second connecting member will be described in detail with reference to FIG. First, as shown in FIG. 3A, adjacent reinforcing bars 11a, 11b, 11c, 11d in the reinforcing bar cage 10 are passed through the holes formed in the first arc-shaped connecting member 21. Screws are formed at the upper ends of the reinforcing bars 11a to 11d, and the first connecting member 21 is positioned by the nuts 23 previously screwed into the screws.

Next, as shown in FIG. 3B, the two reinforcing bars 11b and 11c penetrating the first connecting member 21 are fixed to the first connecting member 21 by the nut 24.

Next, as shown in FIG. 3C, the two reinforcing bars 11a and 11d located at both ends penetrating the first connecting member 21 are arranged in an arc shape above the first connecting member 21. It is passed through the hole formed in the connecting member 22 of 2. The second connecting member 22 is positioned when its lower surface is in contact with the upper surface of the first connecting member 21.

Further, a concave recess 29b is provided on the lower surface of the second connecting member 22, and when the second connecting member 22 is arranged on the upper surface of the first connecting member 21, from the upper surface of the first connecting member 21. The upper ends of the protruding reinforcing bars 11b and 11c and the nut 24 are adapted to fit in the recess 29b. The recess may be provided on the upper surface of the first connecting member 21, or may be provided on both the upper surface of the first connecting member 21 and the lower surface of the second connecting member 22.

Next, the two reinforcing bars 11a and 11d at both ends penetrating the second connecting member 22 are fixed to the second connecting member 22 by the nut 26.

Next, as shown in FIG. 3D, the insertion reinforcing bar 13 is screwed into the screw hole 29a formed in the second connecting member 22 to fix it. A screw 13a is formed on the lower end side of the insertion reinforcing bar 13.

Even if the screw hole 29a is formed in a through hole without a screw and nuts are screwed on the upper and lower surfaces of the second connecting member 22 on the upper and lower surfaces of the screw 13a of the rebar 13 to be fixed. Good. In this case, it is preferable to appropriately adjust the height of the recess 29b so that the lower nut fits in the recess 29b.

By using a member having higher strength than ordinary reinforcing bars such as ultra-high strength reinforcing bars as the insertion reinforcing bars 13, the diameter of the reinforcing bars can be reduced as compared with the case of using ordinary reinforcing bars, and the reinforcing bars at the pile head are overcrowded. Can be prevented. Further, the cost can be reduced by inserting the ultra-high strength reinforcing bar and using it only for the reinforcing bar 13.

As described above, the four adjacent reinforcing bars 11a to 11d and one insertion reinforcing bar 13 can be connected to each other in the reinforcing bar cage 10 via the first connecting member 21 and the second connecting member 22. ..

Although the first connecting member 21 and the second connecting member 22 are arranged in contact with each other in FIG. 3, the overall position of the connecting member 21 and the connecting member 22 can be adjusted by adjusting the position of the nut 23. It can be adjusted up and down.

FIG. 4 shows another connection example of the present embodiment. In the example of FIG. 4, three reinforcing bars 11e, 11f, 11g adjacent to each other in the reinforcing bar cage 10 and one insertion reinforcing bar 13 are provided via the first connecting member 41 and the second connecting member 42. It is connected by the same configuration as.

Further, in FIGS. 3A to 3D, for example, three reinforcing bars are fixed to the first connecting member 21, and a total of five reinforcing bars and one or two insertion reinforcing bars 13 are attached. The widths of the connecting members 21 and 22 may be changed according to the diameter of the insertion reinforcing bar 13 to be used, and the circumferential direction of the connecting members 21 and 22 and the recesses 29b may be changed as necessary. You may change the size of.

As the first connecting member 1 and the second connecting member 2 of FIGS. 2A and 2B, the connecting members 21 and 22 of FIGS. 3A to 3D, the connecting members 41 and 42 of FIG. By combining an appropriate number of connecting members for connecting the five reinforcing bars and the one insertion reinforcing bar as described above, as shown in FIGS. 2A and 2B, a plurality of first reinforcing bars are used. The connecting member 1 and the same number of second connecting members 2 can be arranged concentrically with respect to a large number of reinforcing bars 11 arranged on the circumference and all around the circumference.

As described above, as shown in FIG. 2A, the first connecting member 1 and the second connecting member 2 are attached to a large number of reinforcing bars 11 at the upper end of the reinforcing bar cage 10, and the large number of reinforcing bars 11 and the connecting member 1 are attached. , 2 are connected. The installation / connection of FIG. 2A can be performed at the factory.

Next, the reinforcing bar cage 10 of FIG. 2 (a) is transported to the pile construction site, and the insertion reinforcing bar 13 is attached and fixed at the pile construction position as shown in FIG. 3 (d) to fix the reinforcing bar 13 of FIG. 2 (b). As described above, the reinforcing bar cage 10 can be manufactured by inserting the reinforcing bar 13 into each of the second connecting members 2 and fixing the reinforcing bar 13.

Next, a joint portion with a beam at the pile head of a cast-in-place pile in which concrete is placed using the reinforcing bar cage 10 of FIG. 2B will be described with reference to FIG. FIG. 5 is a top view (a) and a side view (b) of a main part schematically showing a joint portion of a pile head of a pile with a beam according to the present embodiment.

As shown in FIG. 5A, the reinforcing bar cage 10 of FIG. 2A is housed in the casing 51 made of steel pipes arranged at the pile construction position, the concrete 52 is cast in the casing 51, and the casing 51 is placed. After the removal, as shown in FIG. 2B, the reinforcing bar 13 is inserted into each second connecting member 2 of the reinforcing bar basket 10 and the reinforcing bar 13 is fixed to prepare a pile 50.

Next, a plurality of main bars B1 and B2 of the beam B are arranged. As a result, as shown in FIGS. 5A and 5B, the plurality of insertion reinforcing bars 13 at the pile head 53 are inserted into the main reinforcing bars B1 arranged at the plurality of lower portions of the beam B. The insertion reinforcing bar 13 does not interfere with the main reinforcing bar B1. It is preferable that the type, number, diameter, and plane position of the insertion reinforcing bars 13 are examined in advance and set in advance.

The main reinforcing bar B1 at the lower part of the beam B may be arranged and then inserted into the connecting member 2 to fix the reinforcing bar 13. After fixing, the hoop reinforcing bars may be vertically spaced outside the inserted reinforcing bar 13 as necessary. Place and rebar.

Next, as shown in FIG. 5B, concrete is poured to form the beam B. As a result, the beam B is located so as to include the pile head 53 in the structure, and the joint portion C between the pile 50 and the beam B is formed at the pile head 53. A footing foundation may be arranged instead of the beam B.

Further, it is preferable that the number and the plane position of the insertion reinforcing bars 13 of FIGS. 2B and 5A are set in advance by a three-dimensional CAD model so as not to interfere with the main reinforcing bar B1 of the beam B. As a result, interference between the insertion reinforcing bar 13 and the main bar B1 of the beam B can be reliably prevented. Therefore, when combining an appropriate number of the connecting members 21 and 22 in FIG. 3 and the connecting members 41 and 42 in FIG. 4, the plane position of the insertion reinforcing bar 13 in the second connecting member is adjusted and changed as necessary. To do. For example, the plane position of the screw hole 29a of the insertion reinforcing bar 13 in the second connecting member 22 of FIG. 3C is adjusted and changed. It is preferable to set the diameter and the number of the insertion reinforcing bars 13 based on a prior study.

As described above, according to the present embodiment, the number of the insertion reinforcing bars 13 of the pile can be smaller than the number of the large number of reinforcing bars 11 arranged on the circumference in the reinforcing bar cage 10, so that the pile, the beam, and the footing foundation can be used. It is possible to eliminate the overcrowded reinforcing bar at the joint portion C of the above.

When a member having excellent strength is used for the inserted reinforcing bar 13 as described above, the strength of the inserted reinforcing bar is higher than that of the normal reinforcing bar. Therefore, the number of the inserted reinforcing bars 13 arranged on the circumference is the number of reinforcing bars. Even if the number is less than 11, the stress can be countered.

Further, according to the present embodiment, the first connecting member and the second connecting member connect a large number of reinforcing bars of the reinforcing bar cage and are arranged over the entire circumference to improve the rigidity in the vicinity of the pile head. Therefore, the risk of buckling of the reinforcing bars at the pile head during an earthquake can be reduced. Furthermore, since it is possible to prevent buckling of the reinforcing bars at the joint between the pile and the beam (or footing foundation) due to the alternating horizontal force due to an earthquake, the mechanical performance of the joint between the pile and the beam (or footing foundation) is improved. Can be planned.

Further, by using nuts instead of welding for attaching the first connecting member and the second connecting member to the reinforcing bar, safety and workability can be improved.

Further, when attaching the insertion reinforcing bar 13, by using a screw type fixing or a nut, the construction can be easily performed even after the lower main reinforcing bar B1 of the beam is arranged.

Although the embodiments for carrying out the present invention have been described above, the present invention is not limited to these, and various modifications can be made within the scope of the technical idea of the present invention. For example, in FIGS. 3 and 4, a recess in which the upper end of the reinforcing bar protruding from the upper surface of the first connecting member and the nut are accommodated is formed as a bottomed hole in the lower surface of the second connecting member, and the second connecting member is formed. May be configured so that the recess is not exposed to the outside when is arranged on the upper surface of the first connecting member.

Further, in consideration of safety, each reinforcing bar / insertion reinforcing bar is fixed by nut fixing or screw type fixing, but it may be configured to be fixed by welding.

In addition, it goes without saying that the number of each of the first connecting member and the second connecting member can be appropriately set.

Further, the pile to which the present invention can be applied is not limited to the structure shown in FIG. 2, and may be, for example, a steel pipe pile, a PHC pile or an SC pile. In the case of a steel pipe pile or the like, the reinforcing bar cage is a pile head. Treated as a reinforcing bar.

According to the present invention, the number of rebars inserted at the joint between the pile and the beam or the footing foundation can be reduced at the pile head, so that the overcrowded reinforcing bar at the joint between the pile and the beam or the footing foundation can be eliminated. It is possible to solve the problem of interference between reinforcing bars, improve workability, and prevent the reinforcing bars of the pile head from being frustrated during an earthquake.

1,21,41 First connecting member 2,22,42 Second connecting member 10 Reinforcing bar cage 11, 11a to 11d Reinforcing bar 11e to 11g Reinforcing bar 13 Inserted reinforcing bar 23, 24, 26 Nut 29a Screw hole 29b Recess 50 Pile 51 Casing 52 Concrete 53 Pile head B Beam B1, B2 Beam main bar C Joint

Claims (8)

It is a method of connecting a large number of reinforcing bars arranged on the circumference of a pile head and a plurality of inserting reinforcing bars extending above the reinforcing bars when viewed from the upper surface.
A part of the plurality of adjacent reinforcing bars of the large number of reinforcing bars is penetrated through the first connecting member, and the remaining reinforcing bars are fixed to the first connecting member.
The part of the reinforcing bars is fixed to the second connecting member, and
A method of connecting reinforcing bars by fixing the inserted reinforcing bars to the second connecting member to connect the plurality of reinforcing bars and the inserted reinforcing bars. The plurality of adjacent reinforcing bars are at least three reinforcing bars, two reinforcing bars at both ends of the at least three reinforcing bars are passed through the first connecting member, and the remaining at least one reinforcing bar is the first reinforcing bar. The reinforcing bar connecting method according to claim 1, wherein the reinforcing bar is fixed to the connecting member of 1. The reinforcing bar connection according to claim 1 or 2, wherein the first connecting member and the second connecting member are arranged so that the upper surface of the first connecting member and the lower surface of the second connecting member are in contact with each other. Method. The reinforcing bar connecting method according to any one of claims 1 to 3, wherein the inserted reinforcing bar is screwed into a screw portion of the second connecting member and fixed. The reinforcing bar connecting method according to any one of claims 1 to 3, wherein the inserted reinforcing bar is passed through a hole provided in the second connecting member and fixed with a nut. The reinforcing bar according to any one of claims 1 to 5, wherein the first connecting member and the second connecting member are arranged concentrically with respect to a large number of reinforcing bars arranged on the circumference and all around the circumference. Connection method. The number of the inserted reinforcing bars and the fixing position of the inserted reinforcing bars in the second connecting member are set so that the inserted reinforcing bars do not interfere with a plurality of main bars of the beam or footing foundation arranged at the pile head. The reinforcing bar connecting method according to claim 6. It is a connecting structure of a large number of reinforcing bars arranged on the circumference of the pile head of the pile when viewed from the upper surface and a plurality of inserting reinforcing bars extending above the reinforcing bars.
A part of the plurality of adjacent reinforcing bars of the large number of reinforcing bars penetrates the first connecting member, and the remaining reinforcing bars are fixed to the first connecting member.
Some of the reinforcing bars are fixed to the second connecting member,
A reinforcing bar connecting structure in which the plurality of reinforcing bars and the inserted reinforcing bars are connected by fixing the insertion reinforcing bars to the second connecting member.

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