著者
吉敷 祥一 山田 哲 竹内 徹 鈴木 一弁 岡田 健 和田 章
出版者
日本建築学会
雑誌
日本建築学会構造系論文集 (ISSN:13404202)
巻号頁・発行日
vol.69, no.575, pp.113-120, 2004
被引用文献数
10 5

Many steel structures suffered damage at beam-to-column connections under the Northridge and Hyogo-ken Nanbu Earthquakes more than 8 years ago. After these earthquakes, a remarkable number of studies have been made on beam-to-column connections in U.S. and Japan. Nevertheless, in those studies, little attention has been paid to the point of repairing. The purpose of this study is to propose new ductile steel structure frame system, which realizes not only structural performances but also easy repairing after heavy earthquake. This system is based on bolted connections with split-tee. Main feature of this system is to limit plastic deformation to the splittee at bottom flange. To the contrary, the split-tee at top flange can be kept in elastic, because the center of rotation stays at the top flange of beam end.Consequently, when the structure using this system suffers compulsory deformation under the earthquake, the deformation concentrates on the split-tee at bottom flange. Finally, two series of static tests were conducted. First series are axial loading tests of the weak-web-split-tee elements, and second series are bending tests of beam-to-column connections having weak-web-split-tee. From the result of these tests, we verified that this system had efficient deformation capacity. In addition, the damaged part of this system would.be easy to repair or change to new one.
著者
八木 尚太朗 伊山 潤 福島 佳浩 吉敷 祥一 石田 孝徳 清家 剛 山田 哲
出版者
日本建築学会
雑誌
日本建築学会構造系論文集 (ISSN:13404202)
巻号頁・発行日
vol.86, no.788, pp.1400-1411, 2021-10-30 (Released:2021-10-30)
参考文献数
19

From a viewpoint of continuous use of buildings after an earthquake, it is important to understand the behavior and damage progress of non-structural elements such as dry partition wall under a large deformation owing to earthquake, and to establish a method to monitor the condition of non-structural element in a qualitative manner as well as in a quantitative manner. In this paper, first the past studies on loading experiments for dry partition wall were summarized, showing that enough studies considering the effect of opening and the behavior of walls located away from beam location have not been done. Based on the review of past studies, a full-scale static loading test of steel moment frame with dry partition walls was performed. The specimen has two frames; one frame has a flat wall without opening and the other frame has a wall with a door opening and a corner in the frame. In the latter frame, some part of the wall is placed not directly under the beam. Static cyclic loading was applied, increasing the peak story drift up to as large as 1/33. In the experiment, visual observation was performed at each loading step. Rotation angle and vibration of the walls was also measured using MEMS acceleration sensors. The flat wall had relatively few board cracks and other damage. However, the boards on upper layer in the center part of the wall began to rock at the loading step of a 1/100 story drift. Then at 1/50, the boards showed out-of-plane deformation and when unloading after reaching 1/33, boards fell off. On the other hand, on the wall with the opening, a gap opening between the boards, and a crack on the L-shaped boards at the corner of the opening were observed at a relatively small story drift angle of 1/400. Regarding the wall located away from the beam, damage was concentrated on the wall which was orthogonal to the frame and not under the beam. The wall rotated around the vertical axis, and this was thought to be due to the difference of trackability to the structure between walls. Due to this behavior, a crack at the corner of the wall was seen at the story drift angle of 1/400, and at 1/75 the upper track opened, and studs were seen to come off. The rotation angle and the vibration of the walls were measured by MEMS acceleration sensors. The measurement result corresponded well with the damage observation. It was found from the measurement results that there were signs before damage and behavior of walls could be visually confirmed. Moreover, it was found that the vibration frequency of the damaged wall decreased (period became longer) as the loading progressed. This change may be representing the damage development in the wall. From these observations, it was confirmed that the MEMS acceleration sensor can capture small movement implying damage in partition wall in a quantitative manner, but more study should be necessary about the relationship between the measured deformation and the degree of damage and performance degradation, to utilize accelerometers for structural health monitoring of partition walls.
著者
八木 尚太朗 清家 剛 山田 哲 石田 孝徳 吉敷 祥一 上瀧 敬太 テンデラン ランディ
出版者
一般社団法人 日本建築学会
雑誌
日本建築学会技術報告集 (ISSN:13419463)
巻号頁・発行日
vol.26, no.64, pp.869-874, 2020-10-20 (Released:2020-10-20)
参考文献数
13
被引用文献数
1

Full scale loading test up to large story drift on Exterior Wall of ALC panel with window and door attached to steel moment frame was conducted. No damage was observed on the surface without openings except for the bottom of the panel. On the surface with openings, many damages such as cracks in the panel and breaks in the welding of the substrate were observed especially at large story drift angle of 1/50 or more. In addition, degrading of the openablility of the window and door according to residual story drift angle were examined.
著者
山田 哲 吉敷 祥一 島田 侑子 石田 孝徳
出版者
東京工業大学
雑誌
基盤研究(B)
巻号頁・発行日
2012-04-01

本研究の目的は、大地震時に鉄骨造建物が倒壊に至るまでの3次元挙動を明らかにし、耐震設計における安全余裕度を明らかにすることである。そのためには、構成部材の現実的な挙動を反映した応答解析を行う必要があることから、主要部材であり耐震要素でもある柱と梁を対象に、地震時の現実的な条件を反映した実験を実施し、3次元応力下で部材が最大耐力に到達し、その後復元力を喪失するまでの挙動を把握した。そして、部材の挙動を反映した数値解析を行うための、解析プログラム作成に取り組んだ。
著者
吉敷 祥一 高山 大 山田 哲 エネ ディアナ 小西 克尚 川村 典久 寺嶋 正雄
出版者
Architectural Institute of Japan
雑誌
日本建築学会構造系論文集 (ISSN:13404202)
巻号頁・発行日
vol.77, no.680, pp.1579-1588, 2012
被引用文献数
4

Evaluation of bi-directional characteristics of base-isolation devices is a very important issue for base-isolated structures. This paper describes a bi-directional loading test of U-shaped steel dampers widely-used for energy dissipation in base-isolated structures. The major findings obtained from the test are as follows: (1) torsion-induced residual deformation leads to contact with damper connections; (2) evaluation method of cyclic deformation capacity, which divides bi-directional orbit into deformations in 0 and 90 degree, is proposed and the validity is verified; (3) cyclic deformation capacity is reduced by cumulative torsion; (4) two indices <i>J<sub>c</sub></i> and <i>J<sub>f</sub></i> proposed in this paper can evaluate the limitation of cumulative torsion until contact with connections and the tendency of torsioninduced reduction of cyclic deformation capacity.