著者

永井 拓生

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.29, no.73, pp.1279-1284, 2023-10-20 (Released:2023-10-20)

参考文献数

5

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This paper examines the structural characteristics of the Former Hidaka-Town-Office, located in Toyooka-city, which was constructed in 1935, as well as the corrosion deterioration of its wooden members. A comparison with previous research reveals that the structure aligns well with the advanced design of Western-style wooden buildings from the early Showa era. The construction of the roof trusses is mechanically rational, but the joints connecting beams and braces may be fragile. Most of the corrosion deterioration in the wooden members was found within the outer walls, while other parts of the building remain in good condition without significant deterioration.

著者

永井 拓生 長田 剛和

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.29, no.72, pp.737-740, 2023-06-20 (Released:2023-06-20)

参考文献数

6

被引用文献数

1

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Reed is considered a useful ingredient for structural materials from the viewpoint of sustainability as well as its high tensile strength. In this report, for the aim of verifying the practicality of Reed-made Strand Board (RSB), we produced the small prototypes and discussed the basic performance focusing on the relationship between the parameters related to the manufacture, such as the length and orientation angle of strands, and the out-of-plane bending performance. As a result, RSB has a effective correlation between the manufacturing parameters and the bending properties and satisfies the required performance adequately.

著者

永井 拓生 陶器 浩一

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.22, no.52, pp.925-928, 2016 (Released:2016-10-20)

参考文献数

7

被引用文献数

4 4

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In this article, we discuss on the mechanical properties of bamboo as construction material and on the development of handmade joint connecting bamboos, based on the results of some experiments. We used them in the planning of the actual building as reported in the previous paper (Part 1).We sampled some test pieces in the bamboo forest near the building site, and conducted experiments to evaluate the strength of bamboo. Joint making method was also developed by repeating some test trials. We propose two types of method, which have convenience for manual work and enough reliability in securing necessary strength.

著者

藤井 香菜子 新井 遥 若林 航也 深和 佑太 戸邉 亮司 永井 拓生 中川 純 田辺 新一

出版者

日本建築学会

雑誌

日本建築学会環境系論文集 (ISSN:13480685)

巻号頁・発行日

vol.87, no.802, pp.895-906, 2022-12-01 (Released:2022-12-01)

参考文献数

35

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Partial insulation retrofitting is an effective method for improving thermal insulation in existing houses as its construction cost is lower than that of total insulation retrofitting. This study aimed to clarify the actual conditions of the thermal environment in partially insulated retrofitted houses in summer and winter. Furthermore, the size of insulated areas and heating methods were examined from perspective of energy consumption and health. Field surveys on indoor environments were conducted in an actual partially insulated retrofitted house in Chiba prefecture. Subsequently, we show the effects of different insulation areas and heating methods on energy consumption and health.

著者

永井 拓生 沖 恵輔 長野 容平 木原 湧

出版者

一般社団法人 日本建築学会

雑誌

構造工学論文集B (ISSN:09108033)

巻号頁・発行日

vol.69B, pp.119-128, 2023 (Released:2023-04-07)

参考文献数

42

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The bending failure of full-culm bamboo is usually preceded by bending failure perpendicular to the fibers of the bamboo culm walls. Therefore, it is important to evaluate the stress perpendicular to the fiber that accompanies the bending of the bamboo culm. Brazier effect is considered one of the factors that cause this stress. In this paper, we discuss the bending failure mechanism and bending strength of round bamboo culms with formulation of the Brazier effect theory, numerical analysis, and experiments.According to the Brazier effect theory, when the bending moment for the bamboo culm is small, the bending stress perpendicular to the fiber is about 6 % of the stress parallel to the fiber. Also, the finite element analysis results and the Brazier effect theory showed good agreement in some conditions. The stress perpendicular to the fiber by numerical analysis lies between the linear approximation and the Brazier effect theory and is affected by the internode length. As a result of the bending experiment using Madake bamboo, the stress distribution in the part of the bamboo culm that is not directly subjected to the external force agrees well with the Brazier effect theory. However, it was observed that at the point where the concentrated load was applied, a large additional bending stress perpendicular to the fiber was generated in the culm wall, leading to bending failure of the bamboo culm.

著者

永井 拓生

出版者

一般社団法人 日本木材学会

雑誌

木材学会誌 (ISSN:00214795)

巻号頁・発行日

vol.69, no.2, pp.66-78, 2023-04-25 (Released:2023-04-29)

参考文献数

28

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ヨシ群落の適切な管理保全を達成するために,ヨシ(Phragmites australis)の活用法の確立は重要な課題である。本研究では,将来的なヨシ活用の実現を目標とし,ヨシ稈の形状と力学的特性について基礎的な調査を行った。ヨシ稈の比重・曲げ強度・曲げヤング係数には互いに強い正の相関が確認された。これらの特性値はいずれも根際と穂先あたりでは相対的に小さく,中腹の胸高さあたりで最大となる。また,この付近では節同士の間隔が他部位よりも相対的に大きく,節の数が少ない。つまり,材質の強化による補強が行われている。一方,根際付近では稈断面寸法が他部位より大きいことに加え,節同士の間隔が詰まっており,形状操作による補強が行われている。このように,ヨシ稈においては草丈に亘る質量の増加を防ぎつつ各部の補強がなされており,構造力学的に非常に効率的な材料配置となっていることが確認できた。

著者

キム キョンソク 永井 拓生 新谷 眞人

出版者

一般社団法人日本建築学会

雑誌

学術講演梗概集. B-1, 構造I, 荷重・信頼性,応用力学・構造解析,基礎構造,シェル・立体構造・膜構造 (ISSN:13414453)

巻号頁・発行日

vol.2010, pp.317-318, 2010-07-20

著者

新谷 眞人 堀田 祐介 永井 拓生

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 : journal of architecture and building science (ISSN:13419463)

巻号頁・発行日

vol.19, pp.135-140, 2004-06-20

参考文献数

9

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This Paper reports Honeycomb structure made of aluminum alloy in "Brugge 2002 Pavilion". Honeycomb and Sandwitched-panel have completely different strength and rigidity each other. The layout of these structural elements defines the stress diagrams in the both of structure and expression of the architectural patterns. The transparency of honeycomb, directed by the diagrams, makes the space and the structure of the pavilion abstractive. The synthesis of architectural expression and structural system harmonizes the Pavilion to the town with the medieval atmosphere. The work inherits "Realization of new spatial expression by abstracted structure" in "K residence at Sakura Jousui".