KR20240077298A - Connection structure for column and asymmetric beam and slim floor having the same - Google Patents

Abstract

The joint structure of a column and an asymmetric beam is disclosed. In the joint structure of a column and an asymmetrical beam according to an embodiment of the present invention, the asymmetrical beam includes an upper flange, a lower flange with a wider width than the upper flange, and a web connecting the upper flange and the lower flange, and the upper flange is a column. It includes a first part connected to the first part, a second part smaller in width than the first part, and a notch part connecting the first part and the second part.

Description

Joint structure of column and asymmetric beam and slim floor having the same {CONNECTION STRUCTURE FOR COLUMN AND ASYMMETRIC BEAM AND SLIM FLOOR HAVING THE SAME}

The present invention relates to a joint structure of a column and an asymmetrical beam and a slim floor having the same. More specifically, it relates to a joint structure of a column and an asymmetrical beam with excellent earthquake resistance performance and a slim floor having the same.

Recently, as the number of aging apartments increases, interest in reconstruction and remodeling is increasing.

Apartment remodeling is divided into horizontal expansion, which expands the household balance, and vertical expansion, which increases the number of households as the number of floors increases.

Since most of the apartments subject to remodeling are reinforced concrete wall structures, construction companies are trying to proceed with horizontal and vertical extension structures using wall structures, but the issue of foundation reinforcement has not been resolved.

In particular, the burden of adding additional load to the existing structure during vertical expansion, as well as the need for large-scale foundation reinforcement due to earthquake-resistant design standards that have been strengthened compared to the past, not only increases construction costs, but also makes construction very difficult due to the narrow work space. Furthermore, there are many structural differences of opinion regarding foundation reinforcement during vertical expansion, so it rarely passes deliberation, so there are very few cases that have progressed into actual projects.

Therefore, new expansion methods are being attempted to solve these problems. To solve these problems, steel structure construction methods can be considered, but there are many problems that must be solved even when steel structures are applied. In particular, a technology that secures economic feasibility and constructability while ensuring structural stability while resolving the structural height within the floor thickness of 120 to 150 mm is needed.

Korean Patent No. 1329372 (announced on November 14, 2013)

Embodiments of the present invention are intended to provide a joint structure of a column and an asymmetrical beam with excellent earthquake resistance performance and a slim floor having the same.

According to one aspect of the present invention, in the structure of the joint between a column and an asymmetrical beam, the asymmetrical beam includes an upper flange, a lower flange whose width is larger than the upper flange, and a web connecting the upper flange and the lower flange. The upper flange includes a first part connected to the pillar, a second part having a smaller width than the first part, a pillar including a notch part connecting the first part and the second part, and an asymmetric beam. A junction structure may be provided.

The first part may have a width equal to the width of the lower flange, and the second part may have a width smaller than the width of the lower flange.

The notch portion may be provided in an arc shape.

The asymmetrical steel beam may be made of SN steel, a rolled steel for building structures.

The first portion includes an expanding stiffener attached to the upper flange.

The pillar includes at least one of a square pipe pillar and an H-beam steel pillar.

At least one of the upper flange, the lower flange, and the web may be welded to the outer surface of the column.

Another aspect of the present invention can provide a slim floor having a joint structure of the above-described column and asymmetric beam.

Embodiments of the present invention can secure the performance of the joint between a column and an asymmetrical beam through a simple structure, and do not require the installation of a separate diaphragm on the column, thereby improving productivity by reducing manufacturing costs.

Figure 1 is a cross-sectional view showing a portion that is horizontally expanded to an existing building according to an embodiment of the present invention.
Figure 2 is a perspective view showing a slim floor according to an embodiment of the present invention.
Figure 3 is a perspective view showing the joint structure of a column and an asymmetrical beam according to an embodiment of the present invention.
Figure 4 is a plan view of the joint structure of a column and an asymmetrical beam according to an embodiment of the present invention.
Figure 5 is a plan view of the joint structure of a column and an asymmetrical beam according to another embodiment of the present invention.
Figure 6 is a cross-sectional view taken along line I-I of Figure 3.
Figure 7 is a cross-sectional view taken along line II-II of Figure 3.
Figure 8 is a photograph showing an experimental device for testing joint performance according to an embodiment of the present invention.
Figure 9 is a graph showing the results using an experimental device of the joint structure and performance of an unreinforced asymmetric beam test specimen without an expanded cross-sectional area.
Figure 10 is a graph showing the results using an experimental device of the joint structure and performance of an unreinforced asymmetric beam test specimen installed on an existing external diaphragm.
Figure 11 is a graph showing the results of the joint structure and performance of an embodiment of the present invention using an experimental device.

Since the embodiments described in this specification are only the most preferred embodiments of the present invention and do not represent the entire technical idea of the present invention, various equivalents or modifications that can replace them at the time of filing the present invention are also available. It should be understood as included within the scope of rights.

Singular expressions used in the description may include plural expressions unless clearly implied by the context. The shapes and sizes of elements in the drawings may be exaggerated for clarity.

In this specification, terms such as 'include' or 'have' are intended to refer to the presence of features, numbers, steps, operations, components, parts, or a combination thereof described in the specification, but are not intended to include one or more other features or It should be understood that this does not exclude in advance the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Throughout the specification, ordinal expressions such as “first” and “second” are used to distinguish a plurality of components, and the ordinal used indicates the order of arrangement between the components and the importance of the manufacturing order. That is not the case.

When a component is referred to as being “connected” to another component, it should be understood that it may be directly connected to the other component, but that other components may also exist in between.

Figure 1 is a cross-sectional view showing a portion horizontally expanded to an existing building according to an embodiment of the present invention, and Figure 2 is a perspective view showing a slim floor according to an embodiment of the present invention.

Referring to Figures 1 and 2, the portion that is horizontally extended to an existing building 10, such as an apartment, may be composed of a slim floor 20 that can reduce the floor height of the building by considering the floor thickness of the existing building 10. .

This slim floor 20 includes an asymmetrical beam 40 connected to the column 30, a flat deck 21 installed on the asymmetrical beam 40, and concrete 26 poured on the top of the flat deck 21. ) may include.

The flat deck 21 is intended to serve as a formwork for constructing a slab, and may include a plate part 22 and a reinforcing bar member 23.

The plate portion 22 is composed of a flat plate structure, and the reinforcing bar members 23 are disposed at regular intervals on the plate portion 22 and can be integrally coupled with the plate portion 22.

The reinforcing bar member 23 may include a main bar 24 and a truss bar 25 connected to the main bar 24 in a truss structure.

Figure 3 is a perspective view showing the joint structure of a column and an asymmetrical beam according to an embodiment of the present invention, Figure 4 is a plan view of the joint structure of a column and an asymmetrical beam according to an embodiment of the present invention, and Figure 5 is a It is a plan view of the joint structure of a column and an asymmetrical beam according to another embodiment of the invention, FIG. 6 is a cross-sectional view taken along line I-I of FIG. 3, and FIG. 7 is a cross-sectional view taken along line II-II of FIG. 3.

Referring to FIGS. 3 to 7, in this embodiment, the joint structure of the column 30 and the asymmetrical beam 40 applied to the slim floor structure improves seismic performance through reinforcement of the strength and ductility of the joint. You can do it.

The pillar 30 may be composed of a steel pillar such as a rectangular-shaped square tube pillar or an H-beam steel pillar. The disclosed embodiment is explained by taking a square pipe pillar as an example.

The asymmetric beam 40 may be coupled to the column 30. The asymmetric beam 40 may include an upper flange 50, a lower flange 60, and a web 70 connecting the upper flange 50 and the lower flange 60.

The asymmetrical beam 40 may be made of SN (Steel New) steel, a rolled steel material for building structures. SN steel is a steel with excellent seismic performance whose yield ratio is kept below 0.8.

The asymmetric beam 40 may be made of H-beam steel with different cross sections of the upper flange 50 and the lower flange 60.

The upper flange 50 may have a width W1 that is relatively smaller than the width W2 of the lower flange 60 to facilitate construction of the flat deck 21.

This asymmetrical beam 40 can realize floor height reduction and exterior material reduction by supporting the flat deck 21 on the lower flange 60.

The end of the asymmetric beam 40 may be coupled to the outer surface of the column 30 by welding.

At least one of the upper flange 50, lower flange 60, and web 70 of the asymmetric beam 40 may be joined to the outer surface of the column 30 by a full penetration welding method.

A scallop, which is a weld access hole, can be removed from the web 70 of the asymmetrical beam 40 joined to the pillar 30 of this embodiment.

This is to prevent the stress concentration phenomenon caused by scallops, to smoothly induce stress flow between the column 30 and the asymmetrical beam 40, and to prevent brittle fracture due to notches.

The upper flange 50 includes a first part 51 connected to the pillar 30, a second part 52 whose width is smaller than the first part 51, and a first part 51 and a second part ( It includes a notch portion 53 connecting 52).

The first part 51 may be defined as the end area of the upper flange 50 connected to the pillar 30, and the second part 52 may be defined as the area of the upper flange 50 excluding the first part 51. It can be defined as:

The first part 51 connected to the pillar 30 may have a width W3 that is the same as the width W2 of the lower flange 60. This is to prevent brittle fracture of the joint due to moment hysteresis behavior caused by different cross sections of the upper flange 50 and lower flange 60 connected to the column 30.

The first part 51 may be manufactured integrally with the upper flange 50 when manufacturing the asymmetrical beam 40. In contrast, the first part 51 is a built-up method in which the expansion stiffener 55 is welded and joined to the end area of the upper flange 50 of the asymmetrical beam 40, as shown in FIG. It can be manufactured in one piece.

The width, length, and thickness of the first part 51 may be determined in accordance with the bending moment resistance capacity of the asymmetrical beam 40 required according to the structural design.

The first part 51 and the second part 52 may be connected to each other by a notch portion 53.

The notch portion 53 may be located on both sides of the upper flange 50 in the width direction. The notch portion 53 may be configured in an arc shape to smoothly distribute stress when a load is applied.

This notch portion 53 induces the generation of a plastic hinge when a bending moment is applied to the asymmetrical beam 40, thereby securing the performance of the joint between the column 30 and the asymmetrical beam 40 by increasing the ductility. .

Through this, there is no need to install a separate diaphragm to reinforce the strength of the joint at the joint between the column 30 and the asymmetrical beam 40 of this embodiment.

Figure 8 is a photograph showing an experimental device for testing joint performance according to an embodiment of the present invention. As shown in Figure 8, the experimental device erected an asymmetrical beam with the column lying down, connected an actuator to the end of the asymmetrical beam, and applied the repetitive loading procedure presented in KDS2019 to load it.

Figure 9 is a graph showing the results using an experimental device of the joint structure and performance of an unreinforced asymmetric girder beam test specimen without an expanded cross-sectional area.

Referring to Figure 9, in the case of the unreinforced specimen, the story drift angle (Story Drift Ratio) can be deformed up to 0.08 rad (8% radian), but fracture occurred at the weld joint surface of the column and the upper flange at 0.03 rad. In addition, in the overall hysteresis behavior, it was confirmed that the beam did not reach the total plastic moment (1.0Mp), so the performance of the beam was not demonstrated.

Figure 10 is a graph showing the results of the joint structure and performance of the unreinforced asymmetric beam test specimen installed on the existing external diaphragm using an experimental device.

Referring to Figure 10, in the case of the unreinforced asymmetric beam test specimen installed on the external diaphragm, it was confirmed that the interstory displacement angle showed stable hysteretic behavior in deformation up to the final 0.08 rad, and reached the total plastic moment in the overall hysteresis behavior.

Figure 11 is a graph showing the results of the joint structure and performance of an embodiment of the present invention using an experimental device.

Referring to FIG. 11, it was confirmed that the asymmetrical beam 40 having the expanded first portion 51 of this embodiment exhibited stable hysteresis behavior up to the final 0.08 rad. However, compared to the unreinforced asymmetrical beam test specimen installed on the external diaphragm, it showed somewhat inferior performance in terms of initial stiffness and maximum strength, but exceeded the total plastic moment of the asymmetrical beam (40) by more than 20% and the strength of the column (30) It was confirmed that stable hysteresis behavior occurred without any special problems at the joint surface.

This constitutes only the first part 51 extended from the upper flange 50 of the asymmetrical beam 40, thereby demonstrating stable hysteresis behavior and performance even without a separate reinforcement structure or diaphragm on the column 30 side. I was able to confirm.

In the above, specific embodiments are shown and described. However, it is not limited to the above-described embodiments, and those skilled in the art will be able to make various changes without departing from the gist of the technical idea of the invention as set forth in the claims below.

10: Existing building, 20: Slim floor,
30: Column, 40: Asymmetrical beam,
50: upper flange, 51: first part,
52: second part, 53: notch part,
55: expansion stiffener, 60: lower flange,
70: Web.

Claims (8)

In the joint structure of a column and an asymmetric beam,
The asymmetrical beam includes an upper flange, a lower flange that is wider than the upper flange, and a web connecting the upper flange and the lower flange,
The upper flange is a joint structure of a pillar and an asymmetric beam including a first part connected to the pillar, a second part having a smaller width than the first part, and a notch part connecting the first part and the second part. . According to paragraph 1,
The first part has a width equal to the width of the lower flange, and the second part has a width smaller than the width of the lower flange. A joint structure of a column and an asymmetrical beam. According to paragraph 1,
The notch is a joint structure of a pillar and an asymmetrical beam provided in an arc shape. According to paragraph 1,
The asymmetrical beam is a joint structure of a column made of SN steel, a rolled steel for architectural structures, and an asymmetrical beam. According to paragraph 1,
The first part is a joint structure of a column and an asymmetric beam including an expansion stiffener attached to the upper flange. According to paragraph 1,
The column is a joint structure of a column including at least one of a square pipe column and an H-beam column and an asymmetric beam. According to paragraph 1,
At least one of the upper flange, the lower flange, and the web is a joint structure of a column and an asymmetrical beam where the column is welded to the outer surface of the column. A slim floor having a joint structure of a column and an asymmetrical beam according to any one of claims 1 to 7.

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