著者

林 盛 山﨑 康造 木村 俊明 権藤 智之

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.25, no.60, pp.935-940, 2019-06-20 (Released:2019-06-20)

参考文献数

7

被引用文献数

1 5

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This paper reports the design and construction process of 3D curved reinforced concrete roof in a recent project. In design process, “base model” based on NURBS was used to make consensus on the shape between designers and contractors. In construction, it was utilized for high precision construction and rationalization.

著者

篠原 廉 権藤 智之 蟹澤 宏剛 林 盛 保坂 至

出版者

日本建築学会

雑誌

日本建築学会計画系論文集 (ISSN:13404210)

巻号頁・発行日

vol.85, no.773, pp.1525-1534, 2020 (Released:2020-07-30)

参考文献数

15

被引用文献数

1

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In recent times, the design of three-dimensional (3D) complex shape architectures has become much easier since the advent of 3D-CAD or BIM software. However, the roles of designers, contractors or sub-contractors have become uncertain. For example, in the construction of an architectural project, it is necessary for the associated sub-contractors to possess the prerequisite knowledge of the design processes to avoid discordance of roles or prevent irrelevant design alterations. Additionally, in the application of 3D modeling for designs, the method of transferring design information from designers to contractors is difficult. This research elucidates the construction process of formworks of different 3D complex shape reinforced concrete RC architectures. In particular, this research focused on transferring design information from designers to contractors or sub-contractors. Further, the research analyzed the different options involved in the transfer and clarifies the advantages or disadvantages of each option. The results are outlined below. First, from the investigation of two architectural magazines, “Shinkenchiku” and “Kenchiku–Gijutsu” from January 2000 to July 2019, the authors collected 265 3D complex shape RC architectures and clarified their trends. From these architectures, the authors selected four 3D complex shape RC architectures recently constructed for case studies, each of which had different production system. Second, in the case studies, the authors interviewed the designers, the contractors, and the sub-contractors of the four projects and collected the plans or 3D models. From the data collected, the projects were classified according to the viewpoint of who took the initiative for deciding the construction details or information: the designer (project A), the contractor (project B), the sub-contractor (project C), or the contractor and the sub-contractor (project D). The problems associated with each project are outlined below. 1) Project A: There were no major design alterations or occurrence of discordance because the project designers adhered to the given coordinate values with high precision. However, the task assigned to the designer was too large compared with general cases such as making detailed 3D models. 2) Project B: The BIM manager of the contractors developed the BIM model and pioneered the consensus with the owners and designers. However, the sub-contractors were unable to directly apply the BIM model; therefore, the sub-contractors had to develop their own 3D model for the formwork. 3) Project C: The sub-contractors managed the 3D model unitarily, and design alterations made were reflected on the model quickly; this enabled the NC data for production of the formwork to be directly made from the 3D model. 4) Project D: The contractor and the sub-contractor examined the details of the design or construction method together. They joined design processes and shared the 3D model. Thus, no major design alterations or other problems occurred. Under recent circumstances, deciding who should develop 3D models or other necessary information for construction is difficult because the requisite skills or experiences are dependent on the companies involved. However, noticeable trials were present in project C; the sub-contractor managed the information and realized the smooth transfer of information. As a result, this research clarified the gray areas in the production process: how to transfer information, such as coordinate values; two-dimensional (2D) drawings; surface models; solid models; software, information sharing system, when the aforementioned information is decided, and whether construction drawings are directly made from 3D models.

著者

保坂 至 林 盛 権藤 智之 蟹澤 宏剛 山﨑 康造

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.28, no.68, pp.448-453, 2022-02-20 (Released:2022-02-20)

参考文献数

7

被引用文献数

1

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This paper reveals the detail of the construction management of the formwork of a recent complex shape building construction, Kawaguchi-shi Meguri-no Mori. In this project, the 3D-model manager (3DMr) managed the complex 3D-model of the building and revised it following many changes from the designer or the form factory. In addition, the 3DMr planned the schedule of the approval by the designer for each parts of the building, for the form factory could start the fabrication of the form on time. The management system can be effective for complex shape buildings which require more information sharing and time management.

著者

松村 秀一 権藤 智之 佐藤 考一 森田 芳朗 江口 亨

出版者

日本建築学会

雑誌

日本建築学会計画系論文集 (ISSN:13404210)

巻号頁・発行日

vol.78, no.693, pp.2307-2313, 2013-11-30 (Released:2014-07-10)

参考文献数

18

被引用文献数

1 1

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Major prefabricated houses manufacturers started their business around 1960s and became world class large housing companies. This study clarifies 9 major prefabricated houses manufacturers' developments at early stage by interviews with their in-house engineers and architectural designers as well as analysis of relating documents. Early prefabricated houses were developed by small number of engineers intensively. Various architecture and specialists including foreign architecture, famous architects and academics affected these developments in some aspects. Furthermore, each of early prefabricated houses had many unique characteristics in building systems. Some of them had changed in early stages, while the others still remain nowadays.

著者

櫻川 廉 権藤 智之

出版者

日本建築学会

雑誌

日本建築学会計画系論文集 (ISSN:13404210)

巻号頁・発行日

vol.88, no.803, pp.124-131, 2023-01-01 (Released:2023-01-01)

参考文献数

11

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This paper revealed the characteristics of the development of the building system of Japanese wooden houses from 1966 to 1976, from the survey of 416 evaluation records of wooden house structures by the Building Center of Japan. The results are as follows. First, the building system diversified around 1970 such as platform construction or log construction, in addition, some wooden panel building systems were mass-produced. Second, many building systems can be regarded as a rationalization of the conventional wooden building system, as the parts around the panels remained as posts and beams.

著者

宮谷 慶一 松本 直之 熊谷 亮平 権藤 智之 松村 秀一

出版者

日本建築学会

雑誌

日本建築学会計画系論文集 (ISSN:13404210)

巻号頁・発行日

vol.86, no.790, pp.2689-2698, 2021-12-01 (Released:2021-12-01)

参考文献数

16

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The purpose of this paper is to clarify the cement suppliers for each construction site during the interwar period when cement consumption increased in Japan. Specifically, the authors picked up and analyzed the cement suppliers at each construction site from the contents of the "Completion Reports", which are the construction records made by Shimizu-gumi during this period. There are 3,186 completion reports in total, of which 1,729 have a description of the cement supplier. These 1,792 cases are summarized in tables and figures by use, structure type, prefectures, year of construction, and total floor space. (See Table1-Table3, Fig.2-Fig.3) The findings are as follows: 1. The Cement suppliers can be classified into four types: "Manufacturing Companies", "Shimizu-gumi itself”,"Merchant" and "Supplied by Client". (See Table4) 2. By region, the percentage of “Shimizu-gumi itself” was high in the Kanto, and the percentage of “ManufacturingCompanies” was high in the Hokuriku. On the other hand, the percentage of “Merchant” was high in Chukyo, Osaka, and Kyushu. 3.By period , the percentage of “Merchants” has increased since the Ⅳ period (1936-) .(See Fig.5-Fig.9) 4. The percentage of “Manufacturing Companies” in each region was almost the same as the shipment percentageset by the regulation. (See Table6 and Table7) However, in the Chukyo, the number of cases of Mikawa, which is closely related to the Shimizu-gumi, was the highest. 5. Since the section handling cement was established at the head office, the cases of “Shimizu-gumi itself” were concentrated in the area under the jurisdiction of the head office, especially in Tokyo. 6. Looking at the breakdown of “Merchants” by region, there are some “Merchants” who have a lot of trades, but since there are many cases of "Others", it is indicated that there were trades with various “Merchants”. (See Table8) 7. Looking at the breakdown of “Supplied by Client", there were almost the same number of governments works and private works, and there were many cases of civil works and industry (See Table9). And there were many cases before 1930, when cement sales control began. (See Table9)

著者

今田 多映 権藤 智之

出版者

日本建築学会

雑誌

日本建築学会計画系論文集 (ISSN:13404210)

巻号頁・発行日

vol.85, no.778, pp.2703-2711, 2020 (Released:2020-12-30)

参考文献数

14

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The management of sub-contractors and material suppliers is vital for building construction management which requires a great deal of workers or materials. However, it is difficult to find an appropriate data source for investigating this management information itself, particularly time sequential data. The Shimizu Corporation (“Shimizu-Gumi” in the post-war era) has stored approximately 3,000 construction reports from the post-war era (1923–1941), in which the types of businesses of the sub-contractors or material suppliers is recorded, such as carpentry, plastering, and supply of lumber or cements, among others. The aim of this paper is to investigate the actual condition and the changes introduced in the process of the management of sub-contractors and material suppliers by Shimizu-Gumi in the post-war era. Shimizu-Gumi has been one of the largest general contractors in Japan since the 18th century. The authors recorded the types of businesses of house construction (510 records) and office construction (360 records). Up to 30–36 types of businesses are recorded in each construction report. The authors calculated the “appearance rate” and the “average number of businesses.” The “appearance rate” is the percentage of the construction reports which recorded the name of the target type of business in the total construction reports. The “average number of businesses” is, on an average, how many times the type of business is recorded in one construction report. In some cases, a type of business is recorded more than once in one construction report. The findings are as follows: 1. In house construction, there are 47 types of businesses where the appearance rate is more than 5%, while there are 52 types in office construction, among which 43 types are common. The types of businesses in which the appearance rate is high are carpentry, plastering, and scaffolding, among others. The type of business in which the appearance rate is low is mainly supply of materials, which deals with finishing materials. 2. In office construction, the comparison between wooden construction and non-wooden construction (reinforced concrete, steel, etc.) revealed the difference in the appearance rate or changing process, such as the appearance rate of tiles increasing first in wooden office construction and then in non-wooden construction. 3. The appearance rate increased or decreased in several types of businesses. Some of these changes corresponded to previous studies, such as the increase of “tobi-doko” (the integration of tobi, scaffolders, and doko, earth workers) or the increase of tiles and decrease of bricks. 4. There are approximately five types of businesses in which the average number of businesses is more than 1. In the business of metal doors, according to one construction report, data regarding workers (sub-contractors for construction) and material suppliers are recorded. In future studies, the authors will investigate the names of the workers or companies recorded in the construction reports. This will elucidate the selection of workers or material suppliers by the general contractor, the difference between workers of material suppliers in house construction and office construction, and the changing process of types of businesses by the same workers or material suppliers. In addition, further analysis is required to establish whether these findings can be applied to other general contractors or other types of constructions.

著者

権藤 智之

出版者

首都大学東京

雑誌

研究活動スタート支援

巻号頁・発行日

2013-08-30

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中国で萌芽期にある木造住宅生産の調査を行った。まず、中国の木造住宅生産の現状について木造建築技術応用研究報告(2013年)を翻訳し、推定される木造建築建設量や住民の意識を整理した。次に、木造建築教育施設3施設に対してインタビューを行い、1施設では木造建築を専門とした教育が行われていることを明らかにした。最後に、中国で木造住宅施工経験のある施工会社4社に対するインタビューを行い、中国の2社からは注文住宅を主とする住宅生産の特徴や技能者教育に対するカナダからの支援、日本の2社からは部品調達や技能者教育等での課題を明らかにした。

著者

権藤 智之 上橋 由寛 松村 秀一

出版者

日本建築学会

雑誌

日本建築学会計画系論文集 (ISSN:13404210)

巻号頁・発行日

vol.75, no.647, pp.193-200, 2010-01-30 (Released:2010-04-02)

参考文献数

20

被引用文献数

1 1

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In Okinawa, new wooden house construction starts is very small compared with in the whole Japan. So, wooden house builders in Okinawa have many difficulties, like shortage of lumbers or carpenters. But, from the 1990s, pre-cut lumber shipped from southern Kyushu area have got used in Okinawa. With this new building method, some companies which have no experience of wooden construction moved onto wooden house construction. Most of them build small numbers of wooden houses, and do another business on the other hand. And wooden house building system is influenced by limited distribution channel as well as environmental factor.