JP2022054655A - Beam-column connection structure and outer diaphragm construction method - Google Patents

Abstract

To provide reasonable beam-column connection structure and an outer diaphragm construction method which can greatly reduce cost and time for providing an outer diaphragm while securing necessary proof strength for a beam-column connection, when constituting the outer diaphragm by combining divided diaphragms having the shape obtained by dividing the outer diaphragm into two or more.SOLUTION: Structure of a beam-column connection 1 is configured by joining steel beams 3 to a square steel pipe column 2 through an outer diaphragm 5. The outer diaphragm is configured by combining divided diaphragms 51 having the shape obtained by dividing the same into two or more at corner parts of the square steel pipe column in the state in which the divided diaphragms come into contact with each other at divided faces of the divided diaphragms. The respective divided diaphragms are welded to lateral faces of the square steel pipe column, and the divided diaphragms are not joined to each other at the divided faces.SELECTED DRAWING: Figure 1

Description

There is an application for application of Article 30, Paragraph 2 of the Patent Act. Published on March 1, 2019 (90th) Architectural Institute of Japan Kanto Branch Research Report CDROM version. Published on July 20, 2nd year of Reiwa. 2020 Architectural Institute of Japan Conference (Kanto) Academic Lecture Summary / Architectural Design Presentation Summary DVD

The present invention relates to a structure of a beam-column joint of a structure such as a building, and particularly to a structure of a beam-column joint for joining a steel beam to a square steel pipe column via an outer diaphragm and a method of constructing the outer diaphragm.

When a hollow steel material such as a steel pipe is used for a column in a steel-framed or concrete-filled steel pipe (CFT) structure, when a horizontal force such as an earthquake force acts on the structure, the column-beam joint is H-shaped. A bending moment acts on the column from the end of the beam made of steel or the like. At this time, a pressing force or a tensile force acts on the surface of the column from the flanges at the upper and lower portions of the beam, and out-of-plane deformation occurs on the surface of the hollow steel material constituting the column. When this out-of-plane deformation becomes large, the yield of the column-beam joint occurs in advance before the main structural parts such as columns and beams of the structure fully exert the inherent strength, and the interlayer deformation angle of the structure becomes large. As a result of the excessive amount, the rigidity of the entire structure may decrease and the structure may collapse at an early stage.

Therefore, in the beam-column joint of the structure as described above, a steel plate called a diaphragm is horizontal in order to suppress out-of-plane deformation of the hollow steel surface constituting the column and provide sufficient strength to the beam-column joint. It is provided in the direction so that the pressing force or the tensile force acting from the flange of the beam is transmitted to the column through this diaphragm.

The main methods of the diaphragm include an inner diaphragm method, a through-diaram method, and an outer diaphragm method. Of these, the outer diaphragm method in which the diaphragm is joined to the outside of the column is compared to the inner diaphragm method in which the diaphragm is joined to the inside of the column and the through diaphragm method in which the diaphragm is provided so as to penetrate the cross section of the column. The amount of welding for joining the diaphragm to the column can be reduced.

On the other hand, in the outer diaphragm method, if the diaphragm is made of a single steel plate, it is necessary to insert the annular diaphragm from the end of the column to the joint position of the column in the material axis direction of the column. Construction becomes difficult. Therefore, for example, as in the structure of the beam-column joints 8A to 8C shown in FIGS. 9 to 11, the outer diaphragms 9A to 9A are combined with the divided diaphragms 91 to 93 having a shape in which the outer diaphragms 9A to 9C are divided into two or more. ~ 9C is often configured. Each of the divided diaphragms 91 to 93 is joined to the column 2 by welding or the like, and the boundary between the divided diaphragms 91 to 93 is also welded W or bolted so that stress can be transmitted between the divided diaphragms 91 to 93. It is joined by such as. The steel beam 3 is joined to the outer diaphragms 9A to 9C configured in this way.

Regarding the beam-column joint of the outer diaphragm type, in the technique disclosed in Patent Document 1, a joint surface between the steel plates constituting the outer diaphragm is provided at the corner of the column, and this joint is joined by fillet welding. , The resistance of the outer diaphragm to the out-of-plane tensile force of the square steel pipe column is improved.

Further, in the technique disclosed in Patent Document 2, the outer diaphragm is knitted by a divided diaphragm divided into four at the position of the steel beam joined to the column surface of the square steel pipe column, and these divided diaphragms are bolted to form the steel beam. The outer diaphragm is formed by integrating within the flange width. With this configuration, welding is not performed on the portion near the corner of the square steel pipe column, which is the stress concentration portion in the outer diaphragm, and the strength and toughness are ensured.

Further, in the technique disclosed in Patent Document 3, each of the divided diaphragms obtained by dividing the outer diaphragm is provided with a pillar plate in contact with the pillar, and the divided diaphragms are separated from each other at the tensile joints provided at both ends of the pillar plate. It is bolted. With this configuration, the outer diaphragm is fixed to the column by the frictional force between the column plate and the column, and welding is not used.

Japanese Unexamined Patent Publication No. 2019-163632 Japanese Unexamined Patent Publication No. 2002-173978 JP-A-2017-206823

However, in the techniques disclosed in Patent Documents 1 to 3, the split diaphragms constituting the outer diaphragm are sufficiently restrained by welding, bolt joining, or the like to limit the rotation between the split diaphragms. In need of. Therefore, it is necessary to machine a groove for welding or a bolt hole for bolt joining in the split diaphragm, and join the split diaphragms by welding or bolt joining using a welding material or high-strength bolt. It cannot be said that the cost and time for installing the outer diaphragm at the joint have been sufficiently reduced.

In order to solve the above problems, the present invention provides the outer diaphragm while ensuring the required proof stress at the beam-column joint when the outer diaphragm is formed by combining the outer diaphragms having a shape in which the outer diaphragm is divided into two or more. It is an object of the present invention to provide a rational beam-column joint structure and a method of constructing an outer diaphragm, which can significantly reduce the cost and time for installing the diaphragm.

In order to solve the above problems, the present invention has the following features.

[1] The structure of a column-beam joint formed by joining a steel beam to a square steel pipe column via an outer diaphragm, and the outer diaphragm has a shape divided into two or more at the corner portion of the square steel pipe column. The divided diaphragms to be provided are combined and configured so as to be in contact with each other on the divided surfaces of the divided diaphragms, each of the divided diaphragms is welded to the side surface of the square steel pipe column, and the divided diaphragms are joined to each other on the divided surfaces. The structure of the column-beam joint, which is characterized by not being.

Here, the square steel pipe column shall include not only a square steel pipe column having a curvature at a corner portion but also a welded assembled four-sided box column having a right angle at a corner portion.

[2] The structure of a column-beam joint formed by joining a steel beam to a square steel pipe column via an outer diaphragm, and the outer diaphragm has a shape divided into two or more at the corner portion of the square steel pipe column. The divided diaphragms to be provided are combined and configured so as to be in contact with each other on the divided surfaces of the divided diaphragms, each of the divided diaphragms is welded to the side surface of the square steel pipe column, and the divided diaphragms are welded to each other on the divided surfaces. A structure of a beam-column joint, characterized in that the weld is joined by welding with a welding depth of 50% or less of the plate thickness.

[3] The structure of a beam-column joint according to [1] or [2], wherein the square steel pipe column is a concrete-filled square steel pipe column.

[4] The angle between the flat surface extending the side surface of the square steel pipe column and the divided surface of the divided diaphragm welded to the side surface is 26 degrees or more and 64 degrees or less [1] to [ 3] The structure of the column-beam joint according to any one of.

[5] A method of constructing an outer diaphragm in which an outer diaphragm is attached to a square steel pipe column. A divided diaphragm having a shape in which the outer diaphragm is divided into two or more at the corners of the square steel pipe column is prepared, and the divided diaphragm is prepared. In this state, each of the divided diaphragms is welded to the side surface of the square steel pipe column, and the outer diaphragm is constructed so as not to join the divided diaphragms to each other on the divided surface. Method.

[6] A method of constructing an outer diaphragm in which an outer diaphragm is attached to a square steel pipe column. A divided diaphragm having a shape in which the outer diaphragm is divided into two or more at the corners of the square steel pipe column is prepared, and the divided diaphragm is prepared. In this state, each of the divided diaphragms is welded to the side surface of the square steel pipe column, and the divided diaphragms are welded to each other on the divided surface at a welding depth of 50% or less of the plate thickness. A method of constructing an outer diaphragm, which is characterized by joining by welding.

In the structure of the column-beam joint where the steel beam is joined to the square steel column via the outer diaphragm, most of the force input from the flange of the steel beam to the outer diaphragm is between the flange of the steel beam and the square steel column. It flows to the corner of the square steel tube column via the outer diaphragm in between. Therefore, stress transmission that flows as it is in the outer diaphragms on both sides of the square steel pipe column to the opposite side of the column-beam joint does not occur.

In the structure of the beam-column joint and the method of constructing the outer diaphragm of the present invention, the divided diaphragm has a shape in which the outer diaphragm is divided into two or more at the corners of the square steel pipe column, and the divided diaphragms are divided into two or more at the divided surfaces. Combined with contact conditions, the outer diaphragm is constructed. Therefore, there is no split surface of the split diaphragm on the stress transfer path from the flange of the steel beam to the corner of the square steel pipe column. Therefore, stress transfer between the steel beam and the square steel pipe column can be performed without any trouble even if the divided diaphragms are not joined to each other on the divided surface of the divided diaphragm.

Then, in the structure of the column-beam joint portion and the construction method of the outer diaphragm of the present invention, when the divided diaphragms are not joined to each other on the divided surface of the divided diaphragm, an opening for welding for joining the divided diaphragms to each other is performed. There is no need to machine bolt holes for tip or bolt joining, or to join split diaphragms by welding or bolt joining using welding materials or high-strength bolts, reducing the amount of welding materials and bolts used. Will be done. Further, even when the divided diaphragms are joined by welding with a welding depth of 50% or less of the plate thickness on the divided surface of the divided diaphragm, as compared with the case where they are joined by complete penetration welding or bolt joining, It is simpler and easier to install.

As described above, according to the structure of the beam-column joint and the method of constructing the outer diaphragm of the present invention, the cost and time for providing the outer diaphragm are significantly reduced while ensuring the required yield strength of the beam-column joint. be able to.

When the square steel pipe column is a concrete-filled steel pipe column, most of the compressive force acting on the outer diaphragm from the flange of the steel beam passes through the outer diaphragm between the flange of the steel beam and the square steel pipe column. Then, it flows to the filled concrete inside the square steel pipe column. Therefore, stress transmission that flows as it is in the outer diaphragms on both sides of the square steel pipe column to the opposite side of the column-beam joint does not occur. Therefore, stress transfer between the steel beam and the square steel pipe column can be performed without any trouble even if the divided diaphragms are not joined to each other on the divided surface of the divided diaphragm divided at the corner portion of the square steel pipe column.

When a tensile force acts on the outer diaphragm from the flange of the steel beam, the part of the split diaphragm to which the steel beam is attached receives a large tensile force, and the both sides of the split diaphragm to which the steel beam does not attach receive a tensile force. Since it is not received, the split diaphragm is bent and deformed in the plate surface, and rotation angles are generated on both side portions of the split diaphragm. As a result, both side portions of the split diaphragm protruding from the square steel pipe column are pressed against the other adjacent split diaphragm sides, so that even if the split diaphragms are not joined to each other, the split diaphragms are separated by the bearing pressure. Stress transfer is performed without any trouble.

Further, the angle formed by the flat surface extending the side surface of the square steel pipe column and the divided surface of the divided diaphragm welded to the side surface shall be within the range of arctan 0.5 or more and arctan 2 or less, that is, 26 degrees or more and 64 degrees or less. As a result, even when the steel beam is placed eccentrically with respect to the square steel pipe column, the portions of both sides of the split diaphragm that protrude from both sides of the square steel pipe column are pressed against the other adjacent split diaphragm sides. Can be done. Therefore, even if the divided diaphragms are not joined to each other, stress transfer between the divided diaphragms can be performed without any trouble due to the supporting pressure.

It is a top view which shows the structure of the column-beam joint part of the 1st Embodiment of this invention, and the outer diaphragm constructed by the construction method of the outer diaphragm. It is a side view which shows the structure of the column-beam joint part of the 1st Embodiment of this invention, and the outer diaphragm constructed by the construction method of the outer diaphragm. It is a side view which shows the operation of the outer diaphragm constructed by the structure of the column-beam joint part of the 1st Embodiment of this invention, and the construction method of the outer diaphragm. It is a top view which shows the structure of the column-beam joint part of the 1st Embodiment of this invention, and the operation of the outer diaphragm constructed by the construction method of the outer diaphragm. It is a top view which shows the structure of the column-beam joint part of the 2nd Embodiment of this invention, and the outer diaphragm constructed by the construction method of the outer diaphragm. It is a top view which shows the structure of the column-beam joint part of the 2nd Embodiment of this invention, and the operation of the outer diaphragm constructed by the construction method of the outer diaphragm. It is a top view which shows the structure of the column-beam joint part of the 3rd Embodiment of this invention, and the outer diaphragm constructed by the construction method of the outer diaphragm. It is a top view which shows the structure of the column-beam joint part of the 3rd Embodiment of this invention, and the operation of the outer diaphragm constructed by the construction method of the outer diaphragm. It is a top view which shows the structure of the conventional beam-column joint. It is a top view which shows the structure of the conventional beam-column joint. It is a top view which shows the structure of the conventional beam-column joint.

Hereinafter, embodiments of the method for constructing the beam-column joint and the outer diaphragm of the present invention will be described in detail with reference to the drawings.

A plan view and a side view of the structure of the beam-column joint according to the first embodiment of the present invention are shown in FIGS. 1 and 2, respectively. In the structure of the column-beam joint 1 of the present embodiment, the steel beam 3 is joined to the square steel pipe column 2 via the outer diaphragm 5. The outer diaphragm 5 is configured by combining the divided diaphragms 51 having a shape divided into four at the corner positions of the square steel pipe column 2 so as to be in contact with each other on the divided surfaces of the divided diaphragm 51. Each of the divided diaphragms 51 is welded to the side surface 2S of the square steel pipe column 2, and in this state, the divided diaphragms 51 are in contact with each other on the divided surface, but are not joined.

Alternatively, instead of this, in a state where each of the split diaphragms 51 is welded to the side surface 2S of the square steel pipe column 2, the weld depth of the split diaphragms 51 is 50% or less, preferably 30% or less of the plate thickness. More preferably, they are joined by welding 10% or less.

Here, the corner position is an angle formed by the angle θ between the divided surface 5S of the divided diaphragm and the plane extending the side surface 2S of the square steel pipe column 2 to which the divided diaphragm 51 is welded is 0 to 90 °. Refers to the position where

In the present embodiment, the angle θ between the split surface 5S of the split diaphragm 51 and the flat surface extending the side surface 2S of the square steel pipe column 2 to which the split diaphragm 51 is welded is set to 45 degrees.

Further, the fact that the split diaphragm 51 is configured to be in contact with each other on the split surface of the split diaphragm 51 is defined as a tolerance at the time of manufacturing and construction of the column-beam joint portion 1 and the outer diaphragm 5. It also includes a state in which a gap of 3 mm or less is formed on the divided surface of the diaphragm 51.

Further, the method of constructing the outer diaphragm of the present embodiment is a method of constructing the outer diaphragm in which the outer diaphragm 5 is attached to the square steel pipe column 2. First, as described above, a divided diaphragm 51 having a shape in which the outer diaphragm 5 is divided into two or more at the corners of the square steel pipe column 2 is prepared. Then, the divided diaphragms 51 are combined so as to be in contact with each other on the divided surfaces, and in this state, each of the divided diaphragms 51 is welded to the side surface of the square steel pipe column 2. On the split surface, the split diaphragms 51 are not joined to each other, or the split diaphragms 51 are joined by welding with a welding depth of 50% or less, preferably 30% or less, and more preferably 10% or less of the plate thickness.

In the above welding for joining the divided diaphragms 51 to each other, after welding each of the divided diaphragms 51 to the side surface of the square steel pipe column 2, the divided diaphragm 51 extends from the outside of the outer diaphragm 5 to the corner portion of the square steel pipe column 2. It is preferable to form a groove on each of the divided surfaces and perform two-pass or less, preferably one-pass shielded metal arc welding or gas shielded arc welding. Shielded metal arc welding or gas shielded arc welding may be semi-automatic welding or robot welding. The groove depth is preferably about 6 mm per pass, and the strength of the welding material is preferably equal to or higher than the strength of the steel material constituting the outer diaphragm 5. Further, welding may be omitted without providing a groove in a range of about 10 mm from the outside of the outer diaphragm 5 to prevent melting off during welding.

The structure of the column-beam joint portion 1 of the present embodiment and the operation of the outer diaphragm 5 constructed by the construction method of the outer diaphragm of the present embodiment will be described with reference to the side view of FIG. 3 and the plan view of FIG. .. As shown in FIG. 3, when a horizontal external force such as a seismic force acts on a structure having a beam-column joint 1, a bending moment is generated from the steel beam 3 to the beam-column joint 1 as shown by a white arrow. A compressive force or a tensile force acts on the outer diaphragm 5 from the flange of the steel beam 3. At this time, as shown in FIG. 4, most of the force input from the flange of the steel frame beam 3 to the outer diaphragm 5 is outside between the flange of the steel frame beam 3 and the square steel pipe column 2 as shown by the black arrow. It flows to the corner of the square steel pipe column via the diaphragm 5. Therefore, stress transmission that flows directly through the outer diaphragms 5 on both sides of the square steel pipe column 2 to the opposite side of the column-beam joint does not occur.

In the structure of the beam-column joint 1 and the construction method of the outer diaphragm of the present embodiment, the split diaphragm 51 has a shape in which the outer diaphragm 5 is divided into four at the corners of the square steel pipe column 2, and the split diaphragm 51 has a shape divided into four. The outer diaphragm 5 is configured by combining 51 in a state where they are in contact with each other on the dividing surface. Therefore, the split surface 5S of the split diaphragm 51 does not exist on the stress transfer path from the flange of the steel frame beam 3 to the corner portion of the square steel pipe column 2. Therefore, even if the divided diaphragms 51 are not joined to each other on the divided surface 5S of the divided diaphragm 51, stress transmission between the steel frame beam 3 and the square steel pipe column 2 is performed without any trouble.

Then, in the structure of the column-beam joint portion 1 and the construction method of the outer diaphragm of the present embodiment, when the split diaphragms 51 are not joined to each other on the split surface 5S of the split diaphragm 51, the split diaphragms 51 are joined to each other. There is no need to machine welding grooves or bolt holes for bolt joining, or to join split diaphragms 51 to each other by welding or bolt joining using welding materials or high-strength bolts. The amount of bolts used is also reduced. Further, when the divided diaphragms 51 are joined by welding with a welding depth of 50% or less of the plate thickness on the divided surface of the divided diaphragm 51, it is compared with the case where they are joined by complete penetration welding or bolt joining. It is simpler and easier to install.

As described above, according to the structure of the beam-column joint 1 of the present embodiment, it is possible to significantly reduce the cost and time for providing the outer diaphragm 5 while ensuring the proof stress required for the beam-column joint 1. can.

A plan view of the structure of the beam-column joint according to the second embodiment of the present invention is shown in FIG. In the structure of the beam-column joint 1A of the second embodiment, as shown in FIG. 5, the square steel pipe column 2A is a concrete-filled square steel pipe column in which concrete 2C is filled therein. In other respects, the structure of the beam-column joint 1A of the second embodiment is the same as that of the beam-column joint 1 of the first embodiment.

The structure of the column-beam joint portion 1A of the present embodiment and the operation of the outer diaphragm 5 constructed by the construction method of the outer diaphragm of the present embodiment will be described with reference to the plan view of FIG. When a horizontal external force such as a seismic force acts on the structure having the column-beam joint 1A, most of the compressive force (white arrow on the right side of FIG. 6) acting on the outer diaphragm 5 from the flange of the steel beam 3 is It flows to the filled concrete 2C inside the square steel pipe column 2A via the split diaphragm 51 between the flange of the steel beam 3 and the square steel pipe column 2A. Therefore, to the opposite side of the column-beam joint 1A (left side of the square steel pipe column 2A in FIG. 6) via the split diaphragm 51 on both sides of the square steel pipe column 2A (upper side and lower side of the square steel pipe column 2A in FIG. 6). There is almost no stress transmission that flows. Therefore, stress transmission between the steel beam 3 and the square steel pipe column 2A is not hindered even if the divided diaphragms 51 are not joined to each other on the divided surface of the divided diaphragm 51 divided at the corners of the square steel pipe column 2A. Will be done.

When a tensile force (white arrow on the left side of FIG. 6) acts on the outer diaphragm 5 from the flange of the steel beam 3, the portion of the split diaphragm 51 to which the steel beam 3 is attached receives a large tensile force and the steel beam. Since both side portions to which 3 is not attached are not subjected to tensile force, the bending moment distribution of the split diaphragm 51 is as shown by reference numeral 51M, and the split diaphragm 51 is bent and deformed in the plate surface, and the split diaphragm 51 is subjected to bending deformation on both side portions of the split diaphragm 51. A rotation angle is generated. As a result, of the split diaphragm 51, both side portions protruding from the square steel pipe column 2A are pressed against the other adjacent split diaphragm 51 side, so that the split diaphragm 51 is split by the supporting pressure even if the split diaphragms 51 are not joined to each other. Stress transfer between the diaphragms 51 is performed without any trouble.

Here, as a tolerance at the time of manufacturing and construction of the column-beam joint portion 1 and the outer diaphragm 5, even if there is a gap of 3 mm or less on the divided surface of the divided diaphragm 51, the outer diaphragm 5 is formed from the flange of the steel frame beam 3. When a tensile force acts on the split diaphragm 51, the gap is closed and the split surfaces of the split diaphragm 51 come into contact with each other. Therefore, as described above, stress transfer between the split diaphragm 51 is performed without any trouble by the supporting pressure.

FIG. 7 shows a plan view of the structure of the beam-column joint according to the third embodiment of the present invention. In the structure of the column-beam joint 1B of the present embodiment, as shown in FIG. 7, the steel beam 3 is joined to the square steel pipe column 2A via the outer diaphragm 6 in a state of being eccentric from the center of the square steel pipe column 2A. There is. The outer diaphragm 6 is combined so that the divided diaphragms 61 to 63 having a shape divided into four at the corner positions of the square steel pipe column 2A are in contact with each other on the divided surfaces 6S1 and 6S2 of the divided diaphragms 61 to 63. It is configured. Each of the divided diaphragms 61 to 63 is welded to the side surface 2S of the square steel pipe column 2A, and in this state, the divided diaphragms 61 to 63 are in contact with each other on the divided surface, but are not joined.

In the structure of the column-beam joint 1B and the construction method of the outer diaphragm of the present embodiment, the split diaphragm 61 to which the steel beam 3 eccentric from the center of the square steel pipe column 2A is joined is the split diaphragm 61 among the four split diaphragms 61 to 63. It is formed asymmetrically.

Specifically, as shown in FIG. 7, of the divided surfaces 6S1 and 6S2 in which the divided diaphragm 61 contacts the other divided diaphragms 62 and 63, the divided surface 6S1 on the side closer to the steel frame beam 3 is the divided diaphragm 61. The angle θ1 formed with respect to the extended plane of the square steel pipe column 2A on the side to be welded is set to arctan 0.5, that is, 26 degrees.

Further, of the divided surfaces 6S1 and 6S2 of the divided diaphragm 61, the divided surface 6S2 on the side far from the steel frame beam 3 is relative to the plane on which the side surface 2S of the square steel pipe column 2A on the side to which the divided diaphragm 61 is welded is extended. The angle θ2 formed is set to arctan 2, that is, 64 degrees.

Regarding other points, the structure of the beam-column joint 1B and the construction method of the outer diaphragm of the third embodiment are configured in the same manner as the construction method of the beam-column joint 1A and the outer diaphragm of the second embodiment. There is.

The structure of the column-beam joint portion 1B of the present embodiment and the operation of the outer diaphragm 6 constructed by the construction method of the outer diaphragm of the present embodiment will be described with reference to the plan view of FIG. When a horizontal external force such as a seismic force acts on the structure having the column-beam joint 1B, most of the compressive force (white arrow on the right side of FIG. 8) acting on the outer diaphragm 6 from the flange of the steel beam 3 is It flows to the filled concrete 2C inside the square steel pipe column 2A via the split diaphragm 61 between the flange of the steel beam 3 and the square steel pipe column 2A. Therefore, the opposite side of the column-beam joint 1B (the left side of the square steel pipe column 2A in FIG. 8) via the divided diaphragms 62 and 63 on both sides of the square steel pipe column 2A (upper and lower sides of the square steel pipe column 2A in FIG. 8). ) Almost no stress transfer. Therefore, even if the divided diaphragms 61 to 63 are not joined to each other on the divided surfaces 6S1 and 6S2 of the divided diaphragms 61 to 63 divided at the corners of the square steel pipe column 2A, the steel beam 3 and the square steel pipe column 2A can be formed. Stress transfer between them is performed without any trouble.

When a tensile force (white arrow on the left side of FIG. 8) acts on the outer diaphragm 6 from the flange of the steel beam 3, the portion of the split diaphragm 61 to which the steel beam 3 is attached receives a large tensile force and the steel beam. Since both side portions to which 3 is not attached do not receive tensile force, the bending moment distribution of the split diaphragm 61 is as shown by reference numeral 61M, and the split diaphragm 61 is bent and deformed in the plate surface, and the split diaphragm 61 is subjected to bending deformation on both side portions of the split diaphragm 61. A rotation angle is generated.

Then, of the divided surfaces 6S1 and 6S2 in which the divided diaphragm 61 contacts the other divided diaphragms 62 and 63, the divided surface 6S1 on the side closer to the steel beam 3 forms with respect to the flat surface extending the side surface of the square steel pipe column 2A. The angle θ1 is set to arctan 0.5, that is, 26 degrees, and the angle θ2 formed by the split surface 6S2 on the side far from the steel beam 3 with respect to the plane extending the side surface 2S of the square steel pipe column 2A is arctan 2, that is, By setting it to 64 degrees, even if the steel beam 3 is eccentrically arranged with respect to the square steel pipe column 2A as in the present embodiment, both side portions of the divided diaphragm 61 protruding from the square steel pipe column 2A The bending moment distribution is as shown by reference numeral 61M in FIG. 8, and both side portions of the split diaphragm 61 can be pressed against the other split diaphragms 62 and 63 adjacent to each other. Therefore, even if the divided diaphragms 61 to 63 are not joined to each other, stress transfer between the divided diaphragms 61 to 63 is performed without any trouble due to the supporting pressure.

Further, the structure of the column-beam joint portion and the method of constructing the outer diaphragm of the present invention are not limited to the ring type in which the flange of the steel frame beam 3 is welded to the outer diaphragms 5 and 6 as in each of the above embodiments, and the outer diaphragm is not limited to the ring type. A protruding type may be used in which the flanges of the steel beam are bolted together.

Further, in the structure of the column-beam joint portion and the construction method of the outer diaphragm of the present invention, when a plurality of steel frames are attached in a stepped manner, the outer diaphragm configured by combining the divided diaphragms is used for the flange of each steel frame beam. It may be provided at a height.

1, 1A, 1B Column-beam joint 2, 2A Square steel pipe column 2C Concrete 2S Side of square steel pipe column 5, 6 Outer diaphragm 51, 61-63 Divided diaphragm 5S, 6S1, 6S2 Divided surface θ, θ1, θ2 The angle between the side surface of the square steel pipe column and the split surface of the split diaphragm

Claims (6)

It is a structure of a column-beam joint formed by joining a steel beam to a square steel pipe column via an outer diaphragm.
The outer diaphragm is configured by combining divided diaphragms having a shape divided into two or more at the corners of the square steel pipe column so as to be in contact with each other at the divided surfaces of the divided diaphragm.
Each of the split diaphragms is welded to the side surface of the square steel pipe column.
A structure of a beam-column joint, characterized in that the divided diaphragms are not joined to each other on the divided surface. It is a structure of a column-beam joint formed by joining a steel beam to a square steel pipe column via an outer diaphragm.
The outer diaphragm is configured by combining divided diaphragms having a shape divided into two or more at the corners of the square steel pipe column so as to be in contact with each other at the divided surfaces of the divided diaphragm.
Each of the split diaphragms is welded to the side surface of the square steel pipe column.
A structure of a beam-column joint, characterized in that the divided diaphragms are joined to each other by welding at a welding depth of 50% or less of the plate thickness on the divided surface. The structure of a beam-column joint according to claim 1 or 2, wherein the square steel pipe column is a concrete-filled square steel pipe column. Any of claims 1 to 3, wherein the angle between the flat surface extending the side surface of the square steel pipe column and the divided surface of the divided diaphragm welded to the side surface is 26 degrees or more and 64 degrees or less. Structure of column-beam joint described in Crab. It is a construction method of the outer diaphragm that attaches the outer diaphragm to the square steel pipe column.
A divided diaphragm having a shape in which the outer diaphragm is divided into two or more at the corners of the square steel pipe column is prepared.
The divided diaphragms are combined so as to be in contact with each other on the divided surfaces, and in this state, each of the divided diaphragms is welded to the side surface of the square steel pipe column.
A method for constructing an outer diaphragm, characterized in that the split diaphragms are not joined to each other on the split surface. It is a construction method of the outer diaphragm that attaches the outer diaphragm to the square steel pipe column.
A divided diaphragm having a shape in which the outer diaphragm is divided into two or more at the corners of the square steel pipe column is prepared.
The divided diaphragms are combined so as to be in contact with each other on the divided surfaces, and in this state, each of the divided diaphragms is welded to the side surface of the square steel pipe column.
A method for constructing an outer diaphragm, wherein the divided diaphragms are joined to each other on the divided surface by welding at a welding depth of 50% or less of the plate thickness.

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