JP2020204175A - Joint structure for beams in different levels - Google Patents

Abstract

To provide a joint structure for beams in different levels allowing installation to be easily performed in low cost regardless of configurations of end faces and/or heights between different levels.SOLUTION: A joint structure for two steel beams attached in different levels on left and right sides of a column 10, respectively, is configured to rigidly connect a lower level beam 12 at a lower level on one side surface of the column 10, and to connect an upper level beam 14 at a higher level on an upper surface of a bracket 16 projecting from the other side surface of the column 10 without connecting an end surface of the upper level beam 14 on the side surface of the column 10.SELECTED DRAWING: Figure 1

Description

The present invention relates to a beam-beam joint structure, and more particularly to a beam-beam joint structure when there is a step (floor level is different) between the left and right beams of the column.

In shopping centers and large-scale distribution warehouses, composite frames with columns made of reinforced concrete and beams made of steel are often used. In order to fix beams that are orthogonal to each other in the joint, a structure for joining beams having various forms of joints has been developed via fixing hardware as disclosed in Patent Document 1, and experiments and analyzes have been carried out. By accumulating the results, the beam-column joints are designed to be rigid like a normal seismic frame.

Further, as a joining structure for dealing with a difference in beam blame and a step on the floor, for example, it is disclosed that a bracket for supporting the lower portion of the beam disclosed in Patent Document 2 and Patent Document 3 is provided. In the joint structure disclosed in Patent Document 2, an anchor corresponding to the beam height is embedded in a reinforced concrete column, and a steel bracket is fixed to the anchor. By fixing the beam to the upper surface of the steel bracket, the structure can be adapted even when there is a step when joining the beam via the column.

Further, in the joint structure disclosed in Patent Document 2, a square steel pipe having a surface width equal to the width of the beam to be joined is arranged at the center of the reinforced concrete column, and the square steel pipe is provided with respect to the square steel pipe. The end of the beam is welded and the end of the beam including the square steel pipe is buried in the concrete.

Japanese Unexamined Patent Publication No. 6-240759 Japanese Unexamined Patent Publication No. 2005-126973 JP-A-2019-7245

According to the joining structure as disclosed in the above patent document, it is considered that it is possible to join beams having various joint forms and different arrangement heights. However, in the structure in which the steel frame beams are joined via the fixing hardware as disclosed in Patent Document 1, it is difficult to provide a step on the steel frame beams extending in the same direction for joining. In addition, the fixing hardware tends to have a low degree of fixation because it has a complicated shape depending on the shape of the beam joint or is subjected to processing such as providing a notch.

Further, in the case of the joint structure disclosed in Patent Document 2, it is necessary to embed an anchor for fixing the steel bracket in advance in the column. Further, since the steel bracket always overhangs at the end of the beam, the applicable locations may be limited.

Further, in the case of the joint structure disclosed in Patent Document 3, the degree of fixation of the joint changes depending on the fixing method to the steel pipe, and the formwork of the beam-column joint becomes complicated, which complicates the work at the site. Become.

In the present invention, the above-mentioned problems are solved, and regardless of the size (level difference) of the step of the beam attached to the column, the structure of the joint between the column and the beam is simple and the step can be easily constructed. It is an object of the present invention to provide a joint structure of beams.

The joint structure of the step beam according to the present invention for achieving the above object is a joint structure of two steel beams attached to the left and right of the column having different heights, and the lower beam having a low height is a lower beam. The upper beam, which is rigidly joined to one side surface of the column and has a high height, is joined to the upper surface of the bracket protruding from the other side surface of the column, and the end surface of the upper beam is joined to the side surface of the column. It is characterized by not having.

Further, in the joint structure of the stepped beam having the above-mentioned characteristics, the bracket is an end portion of the lower beam penetrating the column. By having such a feature, it becomes possible to fix the lower beam and the bracket to the column at the same time.

Further, in the joint structure of the stepped beam having the above-mentioned characteristics, the upper beam is joined to the bracket via an adjusting member. By having such a feature, the joint structure according to the invention can be applied even when the height of the step is larger than the height due to the lower beam or the upper beam.

Further, in the joint structure of the stepped beam having the above-mentioned characteristics, the fault of the end portion of the upper beam joined to the bracket is smaller than the fault other than the end portion of the upper beam. It is a feature. With such a feature, the joint structure according to the invention can be applied even when the height of the step is smaller than the height of the lower beam or the upper beam.

Further, the column in the joint structure of the stepped beam having the above-mentioned characteristics is characterized in that it is made of reinforced concrete.

According to the joint structure of the stepped beam having the above-mentioned characteristics, the construction can be easily performed regardless of the shape of the end face and the size of the stepped beam.

It is a figure for demonstrating the joint structure of the step beam which concerns on a basic form, and is the figure which shows the structure of the side surface in the extension direction of a beam. It is a figure which shows the AA cross section in FIG. It is a figure which shows the 1st application form in the joint structure of a step beam. It is a figure which shows the 2nd application form in the joint structure of a step beam.

Hereinafter, embodiments relating to the joint structure of the step beam of the present invention will be described in detail with reference to the drawings. First, with reference to FIGS. 1 and 2, a basic form relating to the joint structure of the step beam of the present invention will be described. Note that FIG. 1 is a view showing a state in which the beam related to the joint is viewed from the side surface in the extension direction, and FIG. 2 is a view showing a cross section taken along the line AA in FIG.

[Basic form]
The beams to be joined in the present embodiment are two beams installed on the left and right sides of the column 10, and the heights of the beams located on one side surface of the column and the beams located on the other side surface are different. is there. In the example shown in FIG. 1, the height of one beam extending to the right side (one side surface) of the column 10 is the height of the other beam extending to the left side (the other side surface) of the column 10. It is joined so that it is lower than the beam. Therefore, in the present embodiment, one beam is referred to as a lower beam 12 and the other beam is referred to as an upper beam 14. In the present embodiment, the lower beam 12 and the upper beam 14 are made of steel, and the drawings show that the lower beam 12 and the upper beam 14 are made of H-shaped steel as an example.

In the present embodiment, the lower beam 12 on one side surface of the column 10 and the bracket 16 on the other surface are at the same height. In the present embodiment, the lower beam 12 is arranged so as to penetrate the pillar 10, and the bracket 16 is formed by the end portion of the lower beam 12 penetrating the pillar 10. Compared with the case where the lower beam 12 and the bracket 16 are configured as separate bodies, the number of members can be reduced, and it is not necessary to individually fix both the lower beam 12 and the bracket 16 to the pillar 10.

The upper beam 14 is configured to be joined to the upper surface of the bracket 16, and the column 10 and the end surface (joint) of the upper beam 14 are not joined so as to have a slight gap. When the step h1 between the lower beam 12 and the upper beam 14 is larger than the height h2 due to the lower beam 12 (in the example shown in FIG. 1, the height h2 due to the lower beam 12 and the upper beam 14 The height h4 is the same), and a gap h3 is created between the two. Therefore, when the gap h3 is generated, the lower beam 12 and the upper beam 14 are joined via the adjusting member 18. Here, the configuration of the adjusting member 18 is not limited, but for example, a block material obtained by inserting ribs into a shaped steel material cut to a predetermined size and stiffening may be used.

As a method of joining the lower beam 12 (bracket 16), the upper beam 14, and the adjusting member 18, a known joining method such as welding or bolting may be adopted.

[effect]
According to the joint structure of the step beam as described above, it is possible to cope with a large step by changing the height of the adjusting member 18. Further, since the upper beam 14 is joined to the upper surface of the lower beam 12 penetrating the column 10, the need for processing the steel beam is low and the construction is easy. Further, if the lower beam 12 is rigidly joined to the column 10, it is possible to cope with a long span and a large load.

Further, when the pillar 10 is formed, it is not necessary to form a formwork having a complicated shape, and the workability at the site can be kept good. Further, it can be applied regardless of the end face form of the beam (lower beam 12, upper beam 14). Moreover, since the workability is good, the work can be carried out at low cost.

Further, the upper beam 14 is not joined to the column 10 at an end located on the column 10 side. Then, the upper beam 14 is joined to the upper surface of the bracket 16 formed by the ends of the lower beam 12 (in the examples shown in FIGS. 1 and 2, the upper beam 14 is joined with the adjusting member 18 interposed therebetween). Therefore, the construction is easier than when the upper beam 14 is joined to the side surface of the column 10 or fixed inside.

[First application form]
In the above-mentioned basic embodiment, when the step h1 between the lower beam 12 and the upper beam 14 is larger than the height h2 due to the lower beam 12, the adjusting member is formed between the upper surface of the lower beam 12 and the lower surface of the upper beam 14. It was described that the joining was performed after arranging 18. However, when the step h1 between the lower beam 12 and the upper beam 14 and the height h2 due to the lower beam 12 are equal, the upper beam 14 is directly joined to the upper surface of the lower beam 12 as shown in FIG. It may be configured.

In the case of a step such that no gap is formed between the lower beam 12 and the upper beam 14, both can be directly joined, and the number of members required for joining can be reduced. Further, even in the case of such a joint structure, since the structure is simple to join as in the above-mentioned basic form, the degree of processing of the steel beam is low and the construction can be easily performed.

Further, when constructing the pillar, it is not necessary to construct a formwork having a complicated shape, and the workability at the site can be kept good. Furthermore, it can be applied regardless of the end face form of the beam. Moreover, since the workability is good, the work can be carried out at low cost.

[Second application form]
In the above-mentioned basic form and the first application form, the relationship between the step h1 between the lower beam 12 and the upper beam 14 and the height h2 due to the lower beam 12 is such that h1> h2 or h1 = h2. I explained a case.

Here, when the step h1 between the lower beam 12 and the upper beam 14 is smaller than the height h2 due to the lower beam 12 (h1 <h2), as shown in FIG. 4, the end portion of the upper beam 14 The step may be adjusted by making the height h5 of the blame smaller than the height h4 of the blame of other parts of the upper beam 14.

With such a structure, it is possible to cope with the case where the step h1 is small while maintaining the strength of the beam.

In the embodiment shown in FIG. 4, the lower flange of the upper beam 14 is brought closer to the upper flange to make the height h5 of the end portion smaller than h4, and the step h1 is the height of the lower beam 12. We are trying to deal with cases smaller than h2. However, in the stepped beam joining structure according to the present invention, the upper flange of the lower beam 12 is brought closer to the lower flange, and the bracket 16 is adjusted to reduce the fault so as to cope with the step h1. You can do it.

10 ……… Pillar, 12 ……… Lower beam, 14 ……… Upper beam, 16 ……… Bracket, 18 ……… Adjustment member.

Claims (5)

It is a joint structure of step beams with different heights of two steel beams attached to the left and right of the column.
The low-height lower beam is rigidly joined to one side of the column.
The high upper beam is joined to the upper surface of the bracket protruding from the other side of the column.
A step beam joining structure, characterized in that the end surface of the upper beam is not joined to the side surface of the column. The joint structure of a step beam according to claim 1, wherein the bracket is an end portion of the lower beam penetrating the column. The joint structure of a step beam according to claim 1 or 2, wherein the upper beam is joined to the bracket via an adjusting member. The joint structure of a step beam according to claim 1 or 2, wherein the fault of the end portion of the upper beam joined to the bracket is smaller than the fault other than the end portion of the upper beam. .. The joint structure of a step beam according to any one of claims 1 to 4, wherein the column is made of reinforced concrete.

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