【０００１】
【発明の属する技術分野】
本発明は柱梁接合構造の接合部位に用いられる柱梁接合部コアであって、特に梁フランジの脆性破断を防止でき、かつ製作コストの低減および効率的な製作が可能な柱梁接合部コアに関する。
【０００２】
【従来の技術】
従来の角形鋼管柱およびＨ形鋼梁からなる鉄骨構造物の柱梁接合部では、鋼管柱にダイアフラムを取り付け、ダイアフラムにＨ形鋼梁の梁フランジを接合することで柱と梁とが接合されている。そして、梁に作用する曲げモーメント等の応力は、ダイアフラムを介して鋼管柱に伝達されるようになっている。
【０００３】
しかし、上記の柱梁接合部において柱にスチフナ等の補強が行なわれていない場合には、ウェブから鋼管柱に作用する荷重を梁フランジが負担するようになるので梁フランジの接合部に応力が集中し、梁フランジが脆性破断する１つの要因となっていた。
【０００４】
このような梁フランジの脆性破断を防止する従来技術としては、鋼管柱内に補強を入れた柱梁接合部の構造が特許文献１（特開２００１−２７１４１９公報）および特許文献２（特開平９−３２８８１７号公報）に開示されている。
【０００５】
特許文献１では、十字形に組み立てたスチフナが鋼管柱を分割し、かつスチフナの側端部が梁ウェブに対応する位置に配置されてなる柱梁接合部コアが開示されている。この特許文献１の発明は、十字形に組み立てたスチフナがウェブから鋼管柱に作用する荷重を負担するので、梁フランジの脆性破断を防止できる点で優れた発明である。しかし、特許文献１の発明は部品点数が多く、十字形スチフナの製作や、スチフナと通しダイアフラムとの接合、スチフナと鋼管柱との接合で溶接線が多いことからコスト高となる点で改善の余地があった。
【０００６】
また特許文献２には、角形鋼管内の梁フランジの対応位置にダイアフラムを配置し、梁ウェブに対応する位置に縦スチフナを配置した柱梁接合部コアが開示されている。しかし、特許文献２の発明も、分割された鋼管柱内にダイアフラムやスチフナを溶接し、その後鋼管柱を接合して構成されるため、特許文献１の発明と同様に、溶接線が多くなることからコスト高となる点で改善の余地があった。
【０００７】
【特許文献１】
特開２００１−２７１４１９公報 第３頁−第５頁、図１−図１１
【特許文献２】
特開平９−３２８８１７号公報 第２頁−第５頁、図３および図５
【０００８】
【発明が解決しようとする課題】
本発明は前記従来技術の課題を解決するためにされたものであり、その目的は柱梁接合部における梁フランジの脆性破断を防止し、かつ柱梁接合部コアの製作コストの低減および効率的な製作を可能とすることである。
【０００９】
【課題を解決するための手段】
（１）第１の発明は、鋼管柱５に１以上のＨ形鋼梁８を接合してなる柱梁接合構造の接合部位に用いられる柱梁接合部コア用部材であって、角形鋼管柱部材２に対してほぼ４５度回転した状態で内接角形鋼管３が前記角形鋼管柱部材２内に配設され、かつ前記内接角形鋼管３の隅部が前記Ｈ形鋼梁８の梁ウェブ８ｂの延長線上に位置する状態で前記角形鋼管柱部材２の内周面と溶接されていることを特徴とする柱梁接合部コア用部材である。
（２）第２の発明は、第１の発明記載の柱梁接合部コア用部材の、または、該部材から所定の高さに切り出された部材の角形鋼管柱部材２の上下端に通しダイアフラム４が接合され、前記通しダイアフラム４にＨ形鋼梁８の梁フランジ８ａ端を接合可能としたことを特徴とする。
（３）第３の発明は、第２の発明において、上側の通しダイアフラム４ａの配置位置が、接合される２以上のＨ形鋼梁８の中で最も高い位置にあるＨ形鋼梁８の上側梁フランジに対応し、下側の通しダイアフラム４ｂの配置位置が、接合される２以上のＨ形鋼梁８の中で最も低い位置にあるＨ形鋼梁８の下側梁フランジに対応してなることを特徴とする。
【００１０】
また、本発明の柱梁接合部コア１は以下の工程で製造される。すなわち、角形鋼管柱部材２の内部にほぼ４５度回転した状態で内接角形鋼管３を配置して、前記内接角形鋼管３の隅部と前記角形鋼管柱部材２の内周面とをエレクトロスラグ溶接で接合した後、前記角形鋼管柱部材２の上下端に通しダイアフラム４を、また前記角形鋼管柱部材２および前記内接角形鋼管３の上下端に通しダイアフラム４を接合して製造される。このとき、通しダイアフラム４と角形鋼管柱部材２との接合はＣＯ２溶接、フラッシュバット溶接、拡散融合接合のいずれかによって行い、通しダイアフラム４と内接角形鋼管３との接合はフラッシュバット溶接または拡散融合接合によって行う。
【００１１】
【発明の実施の形態】
以下、本発明の柱梁接合部コアを用いた柱梁接合構造について図面を参照しつつ説明する。図１に示すように本発明の柱梁接合部コア１は、角形鋼管柱部材２、内接角形鋼管３、通しダイアフラム４を主要な構成としている。
【００１２】
角形鋼管柱部材２は、柱梁接合部コア１の上下に接合される角形鋼管柱５に用いられる角形鋼管を少なくとも所定の柱梁接合部コア高さの１倍ないし複数倍の長さとなる所望の長さで切断して構成される。角形鋼管柱部材２の内側には、角形鋼管柱部材２よりも小型角形鋼管からなる角形鋼管柱部材２と同じ長さの内接角形鋼管３が配設されている。本発明の柱梁接合部コア１は角形鋼管柱部材２と内接角形鋼管３との二重管接合構造であるため、縦スチフナの場合と比べて接合箇所が減少し、また、個々の柱梁接合部コアに切り出す前に複数の柱梁接合部コア分の内接角形鋼管の隅部の溶接をまとめて行うことができ、製造コストが大幅に低減する。
【００１３】
内接角形鋼管３は角形鋼管柱部材２に対してほぼ４５度回転した状態で角形鋼管柱部材２の内周面と内接した状態で溶接固定されている。すなわち、図３（ｂ）に示すように、内接角形鋼管３の隅部はそれぞれ角形鋼管柱部材２の４つの内周面中央と内接した状態で溶接されている。また本発明における角形鋼管柱部材２と内接角形鋼管３との接合は、製作コスト低減のために４箇所同時に１人のオペレーターで溶接可能なエレクトロスラグ溶接で行なう。
【００１４】
図４は角形鋼管柱部材２と内接角形鋼管３との接合前の状態を示した図である。角形鋼管柱部材２と内接角形鋼管３との溶接では、まず角形鋼管柱部材２に対して４５度回転した状態で内接角形鋼管３を角形鋼管柱部材２の内部に配置する。このとき角形鋼管柱部材２の内周面と内接角形鋼管３の隅部との間には、それぞれ溶接棒を挿入するための隙間６を確保する。
【００１５】
次に角形鋼管柱部材と内接角形鋼管との隙間６の両側面および底面に、溶融スラグおよび溶融金属の流出を防ぐために当て金７を配置する。そして、角形鋼管柱部材２、内接角形鋼管３、当て金７で囲まれた隙間６の上方から溶接棒を挿入して、角形鋼管柱部材２および内接角形鋼管３を溶接する。なお、製作コスト低減の観点からは、エレクトロスラグ溶接機の可動範囲の上限まで角形鋼管柱部材２および内接角形鋼管３を長尺化し、溶接後の角形鋼管柱部材を切断して複数の柱梁接合部コアを製造するのが好ましい。
【００１６】
また角形鋼管柱部材２および内接角形鋼管３の上下端には、Ｈ形鋼梁８の梁フランジ８ａを取り付けるための通しダイアフラム４が配置されている。この通しダイアフラム４は、Ｈ形鋼梁８と角形鋼管柱部材２との荷重伝達を確実に行なわせるために、角形鋼管柱部材２と溶接される。さらに、柱梁接合部の耐力および剛性を高める必要がある場合には、角形鋼管柱部材２に加えて、内接角形鋼管３と通しダイアフラム４とが溶接される。具体的には、通しダイアフラム４と角形鋼管柱部材２との接合はＣＯ２溶接、フラッシュバット溶接、拡散融合接合のいずれかによって行われ、通しダイアフラム４と内接角形鋼管３との接合はフラッシュバット溶接または拡散融合接合によって行われる。
【００１７】
図２、図３は、本発明の柱梁接合部コア１に角形鋼管柱５およびＨ形鋼梁８を接合した状態を示した図である。本発明の柱梁接合部コア１の通しダイアフラム４の上面および下面には角形鋼管柱５が接合され、柱梁接合部コア１の角形鋼管柱部材２と上下の角形鋼管柱５とが１本の柱を構成するようになっている。
【００１８】
一方、柱梁接合部コア１の通しダイアフラム４の側面にはＨ形鋼梁８の梁フランジ８ａが接合され、角形鋼管柱部材２の側面にはＨ形鋼梁８の梁ウェブ８ｂが接合されている。本発明の柱梁接合部コア１では、角形鋼管柱部材２、内接角形鋼管３および通しダイアフラム４が相互に接合されて一体化していることにより、柱−梁間の荷重伝達が円滑かつ効率的に行なわれる。
【００１９】
本発明の柱梁接合部コア１は、Ｈ形鋼梁８の梁ウェブ８ｂの背面に内接角形鋼管３の隅部が溶接されており、梁ウェブ８ｂの延長線上に内接角形鋼管３による補強部が位置するようになっている。本発明では、内接角形鋼管３によって梁ウェブ８ｂに対応する箇所の面外曲げ耐力および剛性が向上していることから、梁フランジ８ａの応力集中が緩和され、梁フランジ８ａが脆性破断するおそれは大幅に低下している。
【００２０】
また本発明の柱梁接合部コア１では、Ｈ形鋼梁８の一方の梁フランジ８ａが通しダイアフラム４に接合されていなくともよい。例えば、２以上のＨ形鋼梁８が異なる高さで接合されている柱梁接合構造では、本発明の柱梁接合部コア１の上側の通しダイアフラム４を最も高い位置にあるＨ形鋼梁８の上側梁フランジに対応させ、下側の通しダイアフラム４を２以上のＨ形鋼梁の中で最も低い位置にあるＨ形鋼梁８の下側梁フランジに対応させるようにしてもよい［図示を省略する］。
【００２１】
【発明の効果】
本発明の柱梁接合部コアでは、Ｈ形鋼梁の梁ウェブの延長線上に内接角形鋼管による補強部が位置し、梁ウェブに対応する箇所の面外曲げ耐力および剛性が向上していることから、梁フランジの応力集中が緩和され、梁フランジが脆性破断するおそれが大幅に低下している。
【００２２】
また本発明の柱梁接合部コアは角形鋼管柱部材と内接角形鋼管との二重管接合構造であるため、縦スチフナの場合と比べて接合箇所が減少し、製造コストが大幅に低減している。
【００２３】
さらに本発明では、角形鋼管柱部材と内接角形鋼管との溶接は、４箇所同時に１人のオペレーターで溶接可能なエレクトロスラグ溶接で行なうため、少人数の短時間の作業で柱梁接合部コアを製造することができる。特にエレクトロスラグ溶接機の可動範囲の上限まで角形鋼管柱部材および内接角形鋼管を長尺化し、溶接後の角形鋼管柱部材を切断して複数の柱梁接合部コアを製造する場合には、製造コストを更に抑制することもできる。
【図面の簡単な説明】
【図１】本発明の柱梁接合部コアの斜視図である。
【図２】本発明の柱梁接合部コアを用いた柱梁接合構造の斜視図である。
【図３】（ａ）は本発明の柱梁接合部コアを用いた柱梁接合構造の側面図であり、（ｂ）は（ａ）のＡ−Ａ断面図である。
【図４】（ａ）は角形鋼管柱部材と内接角形鋼管との接合前の状態を示した図であり、（ｂ）は（ａ）の一部拡大図である。
【符号の説明】
１ 柱梁接合部コア
２ 角形鋼管柱部材
３ 内接角形鋼管
４ 通しダイアフラム
５ 角形鋼管柱
６ 隙間
７，７ａ 当て金
８ Ｈ形鋼梁
８ａ 梁フランジ
８ｂ 梁ウェブ
１０ 溶接棒[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a beam-to-column joint core used for a joint portion of a beam-to-column joint structure, and particularly to a beam-to-column joint core capable of preventing brittle fracture of a beam flange, and capable of reducing manufacturing costs and efficiently manufacturing. About.
[0002]
[Prior art]
At a beam-to-column joint of a steel structure including a conventional rectangular steel pipe column and an H-shaped steel beam, a column is attached to a steel pipe column, and the beam and a beam are joined by joining a beam flange of an H-shaped steel beam to the diaphragm. ing. Then, stress such as a bending moment acting on the beam is transmitted to the steel pipe column via the diaphragm.
[0003]
However, if the column is not reinforced with a stiffener or the like at the beam-to-column joint, the beam flange bears the load acting on the steel tube column from the web, so stress is applied to the beam flange joint. Concentration was one factor in brittle fracture of the beam flange.
[0004]
As a conventional technique for preventing such brittle fracture of a beam flange, the structure of a column-to-beam joint in which a steel pipe column is reinforced is disclosed in JP-A-2001-271419 and JP-A-2001-271419. -328817).
[0005]
Patent Literature 1 discloses a beam-column joint core in which a stiffener assembled in a cross shape divides a steel pipe column, and side ends of the stiffener are arranged at positions corresponding to the beam webs. The invention of Patent Document 1 is an excellent invention in that a stiffener assembled in a cross shape bears a load acting on a steel pipe column from a web, so that brittle fracture of a beam flange can be prevented. However, the invention of Patent Literature 1 has a large number of parts and has an improvement in that the cost is increased due to the large number of welding lines in the production of the cross-shaped stiffener, the joining of the stiffener to the through diaphragm, and the joining of the stiffener to the steel pipe column. There was room.
[0006]
Patent Literature 2 discloses a column-beam joint core in which a diaphragm is arranged at a position corresponding to a beam flange in a rectangular steel pipe, and a vertical stiffener is arranged at a position corresponding to a beam web. However, the invention of Patent Document 2 is also configured by welding a diaphragm or a stiffener in a divided steel pipe column and thereafter joining the steel pipe columns, so that the number of welding lines increases as in the invention of Patent Document 1. However, there is room for improvement in terms of higher costs.
[0007]
[Patent Document 1]
JP-A-2001-271419, page 3 to page 5, FIG. 1 to FIG.
[Patent Document 2]
JP-A-9-328817, page 2 to page 5, FIG. 3 and FIG.
[0008]
[Problems to be solved by the invention]
The present invention has been made to solve the problems of the prior art, and has an object to prevent brittle fracture of a beam flange at a beam-to-column joint, and to reduce the manufacturing cost of a beam-to-column joint and to reduce the cost. It is possible to make a perfect production.
[0009]
[Means for Solving the Problems]
(1) A first invention is a column-beam joint core member used for a joint portion of a beam-column joint structure in which one or more H-shaped steel beams 8 are joined to a steel tube column 5, wherein the square steel tube column is used. An inscribed rectangular steel pipe 3 is disposed in the rectangular steel pipe column member 2 in a state of being rotated by approximately 45 degrees with respect to the member 2, and a corner of the inscribed rectangular steel pipe 3 has a beam web of the H-shaped steel beam 8. A member for a beam-to-column joint, wherein the member is welded to an inner peripheral surface of the rectangular steel tubular column member 2 while being positioned on an extension of 8b.
(2) A second invention provides a diaphragm for a column-beam joint member according to the first invention, or a diaphragm cut through upper and lower ends of a rectangular steel tube column member 2 cut out to a predetermined height from the member. 4 is joined, and the end of the beam flange 8 a of the H-shaped steel beam 8 can be joined to the through diaphragm 4.
(3) In the third invention, in the second invention, the arrangement position of the upper through-diaphragm 4a is the highest of the two or more H-beams 8 to be joined. The arrangement position of the lower through-diaphragm 4b corresponds to the lower beam flange of the H-beam 8 at the lowest position among the two or more H-beams 8 to be joined. It is characterized by becoming.
[0010]
The beam-column joint 1 of the present invention is manufactured by the following steps. That is, the inscribed rectangular steel pipe 3 is disposed inside the rectangular steel pipe column member 2 while being rotated by approximately 45 degrees, and the corner of the inscribed rectangular steel pipe 3 and the inner peripheral surface of the rectangular steel pipe column member 2 are electrically connected. After joining by slag welding, it is manufactured by passing the diaphragm 4 through the upper and lower ends of the square steel pipe column member 2 and the diaphragm 4 through the upper and lower ends of the square steel pipe column member 2 and the inscribed rectangular steel pipe 3. . At this time, the connection between the through diaphragm 4 and the square steel pipe column member 2 is performed by any of CO 2 welding, flash butt welding, and diffusion fusion bonding, and the connection between the through diaphragm 4 and the inscribed rectangular steel pipe 3 is performed by flash butt welding or This is performed by diffusion fusion bonding.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a beam-column joint structure using the beam-column joint core of the present invention will be described with reference to the drawings. As shown in FIG. 1, a beam-column joint core 1 of the present invention has a square steel pipe column member 2, an inscribed rectangular steel pipe 3, and a through diaphragm 4 as main components.
[0012]
The square steel pipe column member 2 is preferably a square steel pipe used for the square steel pipe column 5 to be joined above and below the beam-to-column joint core 1 at least one or more times as long as a predetermined column-to-column joint core height. It is configured by cutting in length. An inscribed rectangular steel pipe 3 having the same length as the rectangular steel pipe column member 2 made of a rectangular steel pipe smaller than the rectangular steel pipe column member 2 is disposed inside the rectangular steel pipe column member 2. Since the beam-to-column joint 1 of the present invention has a double-pipe joint structure of the square steel pipe column member 2 and the inscribed rectangular steel pipe 3, the number of joints is reduced as compared with the case of the vertical stiffener, Before cutting into beam-joint cores, the welding of the corners of the inscribed rectangular steel pipe for a plurality of column-beam joint cores can be performed collectively, and the manufacturing cost is greatly reduced.
[0013]
The inscribed rectangular steel pipe 3 is welded and fixed in a state of being rotated by approximately 45 degrees with respect to the rectangular steel pipe column member 2 and in contact with the inner peripheral surface of the rectangular steel pipe column member 2. That is, as shown in FIG. 3B, the corners of the inscribed rectangular steel pipe 3 are welded in a state in which they are inscribed in the centers of the four inner peripheral surfaces of the rectangular steel pipe column member 2, respectively. In addition, the joining of the square steel pipe column member 2 and the inscribed square steel pipe 3 in the present invention is performed by electroslag welding which can be welded by one operator at four places simultaneously in order to reduce the manufacturing cost.
[0014]
FIG. 4 is a view showing a state before joining the rectangular steel pipe column member 2 and the inscribed rectangular steel pipe 3. In the welding of the rectangular steel pipe column member 2 and the inscribed rectangular steel pipe 3, first, the inscribed rectangular steel pipe 3 is disposed inside the rectangular steel pipe column member 2 while being rotated by 45 degrees with respect to the rectangular steel pipe column member 2. At this time, a gap 6 for inserting a welding rod is secured between the inner peripheral surface of the rectangular steel pipe column member 2 and the corner of the inscribed rectangular steel pipe 3.
[0015]
Next, a metal plate 7 is disposed on both side surfaces and the bottom surface of the gap 6 between the rectangular steel pipe column member and the inscribed rectangular steel pipe in order to prevent molten slag and molten metal from flowing out. Then, a welding rod is inserted from above the gap 6 surrounded by the square steel pipe column member 2, the inscribed square steel pipe 3, and the backing 7 to weld the square steel pipe column member 2 and the inscribed square steel pipe 3. From the viewpoint of reducing the manufacturing cost, the rectangular steel pipe column member 2 and the inscribed rectangular steel pipe 3 are lengthened to the upper limit of the movable range of the electroslag welding machine, and the rectangular steel pipe column member after welding is cut into a plurality of columns. Preferably, a beam joint core is manufactured.
[0016]
At the upper and lower ends of the rectangular steel pipe column member 2 and the inscribed rectangular steel pipe 3, through-diaphragms 4 for attaching a beam flange 8a of the H-shaped steel beam 8 are arranged. The through-diaphragm 4 is welded to the rectangular steel pipe column member 2 in order to surely transmit the load between the H-shaped steel beam 8 and the rectangular steel pipe column member 2. Further, when it is necessary to increase the strength and rigidity of the beam-column joint, in addition to the square steel pipe column member 2, the inscribed square steel pipe 3 and the through diaphragm 4 are welded. Specifically, the connection between the through-diaphragm 4 and the square steel pipe column member 2 is performed by any of CO 2 welding, flash butt welding, and diffusion fusion bonding, and the connection between the through-diaphragm 4 and the inscribed rectangular steel pipe 3 is performed by flash. This is performed by butt welding or diffusion fusion bonding.
[0017]
FIGS. 2 and 3 are views showing a state in which the square steel pipe column 5 and the H-shaped steel beam 8 are joined to the beam-to-column joint core 1 of the present invention. Square steel pipe columns 5 are joined to the upper and lower surfaces of the through-diaphragm 4 of the beam-to-column joint core 1 of the present invention, and the square steel tube column member 2 and the upper and lower square steel tube columns 5 of the beam-to-column joint core 1 are one. Of the pillars.
[0018]
On the other hand, the beam flange 8a of the H-shaped steel beam 8 is joined to the side surface of the through-diaphragm 4 of the beam-to-column joint core 1, and the beam web 8b of the H-shaped steel beam 8 is joined to the side surface of the rectangular steel pipe column member 2. ing. In the column-to-beam joint core 1 of the present invention, the rectangular steel pipe column member 2, the inscribed rectangular steel pipe 3, and the through diaphragm 4 are mutually joined and integrated, so that the load transmission between the column and the beam is smooth and efficient. It is performed in.
[0019]
In the column-beam joint core 1 of the present invention, the corner of the inscribed rectangular steel pipe 3 is welded to the back of the beam web 8b of the H-shaped steel beam 8, and the inscribed rectangular steel pipe 3 is formed on an extension of the beam web 8b. The reinforcing part is located. In the present invention, since the out-of-plane bending strength and rigidity of the portion corresponding to the beam web 8b are improved by the inscribed rectangular steel pipe 3, stress concentration on the beam flange 8a is reduced, and the beam flange 8a is brittlely fractured. It has dropped significantly.
[0020]
Further, in the column-beam joint core 1 of the present invention, one beam flange 8 a of the H-shaped steel beam 8 does not need to be joined to the through diaphragm 4. For example, in a column-beam joint structure in which two or more H-beams 8 are joined at different heights, the through diaphragm 4 on the upper side of the beam-joint core 1 of the present invention has the highest H-beam. 8 and the lower through-diaphragm 4 may correspond to the lower beam flange of the H-beam 8 at the lowest position among the two or more H-beams. Illustration is omitted].
[0021]
【The invention's effect】
In the column-beam joint core according to the present invention, the reinforcing portion by the inscribed rectangular steel pipe is located on the extension of the beam web of the H-shaped steel beam, and the out-of-plane bending strength and rigidity at the portion corresponding to the beam web are improved. Therefore, the stress concentration on the beam flange is reduced, and the possibility that the beam flange is brittlely fractured is greatly reduced.
[0022]
Further, since the beam-to-column joint core of the present invention has a double pipe joint structure of a square steel tubular column member and an inscribed rectangular steel pipe, the number of joints is reduced as compared with the case of a vertical stiffener, and the manufacturing cost is greatly reduced. ing.
[0023]
Furthermore, in the present invention, since the welding of the rectangular steel pipe column member and the inscribed rectangular steel pipe is performed by electroslag welding which can be welded by one operator at four places at the same time, a small number of people can work in a short time with the column-beam joint core. Can be manufactured. Particularly when the rectangular steel pipe column member and the inscribed rectangular steel pipe are elongated to the upper limit of the movable range of the electroslag welding machine, and when the rectangular steel pipe column member after welding is cut to produce a plurality of beam-column joint cores, Manufacturing costs can be further reduced.
[Brief description of the drawings]
FIG. 1 is a perspective view of a beam-column joint core according to the present invention.
FIG. 2 is a perspective view of a beam-column joint structure using the beam-column joint core of the present invention.
FIG. 3A is a side view of a beam-column joint structure using the beam-column joint core of the present invention, and FIG. 3B is a cross-sectional view taken along line AA of FIG.
FIG. 4A is a view showing a state before joining a rectangular steel pipe column member and an inscribed rectangular steel pipe, and FIG. 4B is a partially enlarged view of FIG.
[Explanation of symbols]
DESCRIPTION OF REFERENCE NUMERALS 1 beam-to-beam joint core 2 rectangular steel pipe column member 3 inscribed rectangular steel pipe 4 through diaphragm 5 rectangular steel pipe column 6 gap 7, 7a padding 8 H-shaped steel beam 8a beam flange 8b beam web 10 welding rod
