• Title/Summary/Keyword: rafter

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A Study on the Structural Safety Analysis for Vinyl House at Wind Load (비닐하우스의 풍하중 구조안전성 검토에 관한 연구)

  • Paik, Shinwon
    • Journal of the Korean Society of Safety
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    • v.34 no.5
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    • pp.72-77
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    • 2019
  • Vinyl house consists of main rafter, lateral member, clamps and polyethylene film. Many vinyl houses are used to grow fruits, flowers and vegetables in the countryside. Due to climate change, vinyl houses are often destroyed by strong winds or typhoons in summer. Many farmers suffer great economic damage from the collapse of vinyl houses. So it is very important to build a safe vinyl house and find a method to withstand this heavy wind load. In this study, a structural analysis was performed on four types of vinyl houses(10-single-4, 10-single-6, 10-single-7, 10-single-10). In addition, axial force and flexural moment are obtained from the structural analysis of four types of vinyl house. For these four types of vinyl house, structural safety was reviewed by obtaining the combined stress ratio by the strength design method. This structural review showed that the specifications for the vinyl house proposed in the design are not safe. Especially, the result of structural analysis for four types of vinyl house showed that the vinyl house structure constructed as a standard was a very dangerous structure. Therefore, it is necessary to devise diverse methods in order to make vinyl houses structurally safe for heavy wind load in the future. Also a variety of manual development is needed to prevent the collapse of vinyl houses at heavy wind load.

A Study on the Structural Safety Analysis for Vinyl House at Snow Load (비닐하우스의 적설하중 구조안전성 검토에 관한 연구)

  • Paik, Shinwon
    • Journal of the Korean Society of Safety
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    • v.34 no.2
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    • pp.34-39
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    • 2019
  • Vinyl house consists of main rafter, lateral member, clamps and polyethylene film. Many vinyl houses are used in the countryside to grow vegetables. These vinyl houses have occasionally been collapsed due to heavy snowfall in winter. Many farmers get a lot of economical damages, if vinyl houses are collapsed. So it is most important to built a safe vinyl house that can withstand heavy snowfall. In this study, a structural analysis was performed on three types of vinyl houses(07-single-01, 10-single-04, 12-single-01). In addition, the structural analysis of the three types of vinyl houses provided axial forces, flexural moment, and combined stress. For these three types of vinyl houses, structural safety was reviewed by obtaining the combined stress ratio by the strength design method. This structural review showed that the specifications for the vinyl house proposed in the design are not safe. Especially, the result of increasing the design snow load by 15 percent and 30 percent showed that the vinyl house structure constructed as a standard for vinyl house was a more dangerous structure. Therefore, it is necessary to revise regulations such as increasing the thickness of rafters or widening the gap in order to make vinyl houses structurally safe for heavy snowfall in the future, and to devise diverse methods to make vinyl houses that are structurally safe.

The Experiment for Performance Evaluation of Column-rafter-purlin Connections of an Arch-type Plastic Multi-span Greenhouse (플라스틱 연동온실 기둥-서까래-도리 접합부의 성능 평가 실험)

  • Choi, Man-kwon;Ryu, Hee-ryong;Cho, Myeong-whan;Yu, In-ho;Kim, Seung-yu
    • Journal of Bio-Environment Control
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    • v.29 no.4
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    • pp.473-479
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    • 2020
  • In this study, the structural experiment was conducted with two types of specimens to investigate the mechanical behavior of the column-rafter-purlin connection of an arch-type greenhouse under monotonic loading. Based on the experimental results, the flexural performance was analyzed for two types of connections, and connection classification was attempted. Type B showed 77% of flexural performance compared to Type A, and both types showed that the rigidity and flexural strength did not reach the level of the full rigid. The behavior of the column-rafter-purlin connection was dominated by local buckling due to deformation of the weld and fasteners. As a result of connection classification by AISC standard, both Type A and B connections showed a result that did not meet the rigid connection performance assumed during design, and were classified as simple connection. Therefore, the connection performance evaluation and classification results show that the greenhouse design should be made in consideration of connection performance and in order to design a reliable greenhouse structure, a study on establishing clear design standards for the greenhouse connection is necessary.

Field Survey and Structural Safety Analysis of Pipe Framed Greenhouses (파이프 골조 온실의 구조 실태 및 안전성 검토(농업시설))

  • 남상운;김문기;유인호
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2000.10a
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    • pp.315-320
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    • 2000
  • An investigation and structural safety analysis was conducted to get the basic data for establishing maintenance strategy of pipe framed greenhouses. The number of greenhouses investigated was 108 in total. Most multi-span greenhouses had narrower width and lower height than the standard 1-2W greenhouse, and most of single-span greenhouses were tunnel type. In multi-span greenhouses, the size and interval of frameworks such as rafter, purline, column, and cross beam were mostly suitable, but frameworks of single-span greenhouses were mostly insufficient.

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Load Transfer Mechanism between Rafter and Cross-beam by 2-D Analysis (이차원해석에 의한 서까래 도리 사이의 하중전달 메카니즘)

  • Jung, Sung-Jin;Hong, Sung-Gul;Kim, Nam-Hee;Lee, Young-Wook;Hwang, Jong-Kook;Joo, Seok-Jun
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2007.04a
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    • pp.229-234
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    • 2007
  • In the structural analysis of the Korean traditional wooden structure, while the understanding of the transfer mechanism of roof load is very important, there are few researches on this subject. So, some modeling methods considering the connecting methods of the Korean traditional wooden structure are suggested, the results using each modeling method are compared, and the most reasonable analytical model is presented in this study.

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A Study on Spatial Advantage of Oegi Purlin in the Construction of Hip and Gable Roof of Buddha Hall in Korean Buddhist Temples (전통 사찰 불전의 팔작지붕 가구구성에서 외기도리의 공간적 이점에 대한 연구)

  • Park, Sae-am;Han, Ji-man
    • Journal of architectural history
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    • v.28 no.4
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    • pp.7-16
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    • 2019
  • In this study, I would like to inquire about the composition of oegi(外機) on the hip and gable roof. Oegi purlin compose the basic member of framework of a hip and gable roof in both sides roof, supporting the inside end of the side rafter. However, the oegi purlin is not simply used to form hip and gable roof. The effects of using oegi purlin have the advantages of spatial. The spatial advantages are the width of the toekan(退間) increases as the oegi purlin escapes from column row and to increase the ceiling height by becoming a point of staying the ceiling. That reflect the desire to expand indoor space due to changes in worship behavior. Oegi purlin was used not only for structural needs, but also for altering in indoor space due to the changing times.

Semantic Analysis of Joseon Dancheong - related Terms in Literature Records (문헌에 기록된 조선시대 단청의 종류 관련 용어에 대한 고찰)

  • Koo, Uk-Hee
    • Journal of architectural history
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    • v.27 no.6
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    • pp.19-30
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    • 2018
  • When identifying the dancheong during the Joseon Dynasty, a great number of the terms used [e.g., dancheong(丹靑), geumbyeok(金碧), danhwak(丹?), danbyeok(丹碧), dannok(丹綠), danchil(丹漆), hyuchil(?漆), hyudong(??), etc.] are found in literature records. However, the details are still veiled. This study investigated the characteristics of dancheong-related terms by analyzing their usages and contents based on literature records from the Joseon period. Architecturally, geumbyeok, danbyeok and dannok were used in temples, and dancheong was painted on walls. In the royal palace, danhwak was adopted while dancheong was also painted on these walls as well. Specifically, danchil was applied to the columns inside and outside buildings while hyudong was painted on rafter, walls and roof tiles. In addition, hyuchil was applied to the inside of the royal palace.

Development of Single-span Plastic Greenhouses for Hot Pepper Rainproof Cultivation (고추 비가림재배용 단동 비닐하우스 개발)

  • Yu, In Ho;Lee, Eung Ho;Cho, Myeong Whan;Ryu, Hee Ryong;Moon, Doo Gyung
    • Journal of Bio-Environment Control
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    • v.22 no.4
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    • pp.371-377
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    • 2013
  • The government has been carrying out a project for supporting the rain shelter for hot pepper as part of measures stabilizing the demand and supply of hot pepper since 2012. However, the eaves height of single-span plastic greenhouses extensively used in farms is low, which are inappropriate for the rainproof cultivation of hot pepper. This study attempted to develop single-span plastic greenhouses which are structurally safe and have the dimensions suitable for the rainproof cultivation of hot pepper as well. The structure status of plastic greenhouses and restructuring wishes of 56 rainproof cultivation farms nationwide were investigated to set up the width and height of the plastic greenhouses. 53% of the plastic greenhouses currently in operation had a width of under 7 m and 64% of their eaves had a height of 1.5 m or less, which accounted for the highest rate. Mostly the width of 7.0 m was desired for the greenhouses and the height of 2.0 m for their eaves, so these values were chosen as the dimensions for the singlespan plastic greenhouses. After an analysis of their structural safety while changing the specifications of the rafter pipe in various ways, 5 kinds of models were suggested considering the frame ratio and installation costs. The 12-Pepper-1 model is a developed single-span plastic greenhouse for hot pepper in which a ${\emptyset}42.2{\times}2.1t$ rafter pipe is installed at an interval of 90cm and the models of 12-Pepper-2 through 5 are the other developed ones in which a ${\emptyset}31.8{\times}1.5t$ rafter pipe is installed at intervals of 60 cm, 70 cm, 80 cm and 90 cm, respectively. As a result of an analysis of economic feasibility of 12-Pepper-2 compared to 10-Single-3 in the notification of the Ministry for Food, Agriculture, Forestry and Fisheries, it turned out that there would be an increase in profits by about 1.2 million won based on one building of a greenhouse sized 672 $m^2$.

A Study on the Hipped-and-Gable-Roof Framework of Muryangsujeon of Buseoksa Temple (부석사 무량수전 측면 지붕부 결구의 구성방식에 관한 재고(再考) - 중국 원대(元代) 이전 목조건축과의 비교를 중심으로 -)

  • Cha, Ju-hwan
    • Korean Journal of Heritage: History & Science
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    • v.49 no.3
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    • pp.78-103
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    • 2016
  • This research is a study on the side framework structure of the hipped and gable roof of Muryangsujeon at Buseoksa Temple. There is a record that Muryangsujeon was deconstructed and repaired in the period of Japanese Occupancy, and its authenticity has continuously been called into question because the structure of the hipped and gable side roofs, and the bonding of the rafters and eaves were not in good order and very different from those of Joseon Dynasty. Scholars date it differently. It is either dated at 13th century or 12th century. This study compares the non-planar configuration of the middle and front proportions of Muryangsujeon's hipped-and-gable-roof framework with those of the Tang(唐) and Song(宋) Dynasties in China. It concludes that the hipped-and-gable-roof framework of those architecture were built with the same technique. The style of architecture that side rafters directly touch the internal security (梁), like in Muryangsujeon, is not usual even among the hipped and garble roofs of the Tang(唐) and Song(宋) Dynasties. The technique of constructing the hipped roofs developed much further after the Tang Dynasty because they began to use garble eaves to build the side structure. The technique seems to have developed greatly by the period of Ming and Qing Dynasties. It also seems that the parallel-flat (平行輻射椽) rafter, which is the form of rafters used between the parallelrafter period and the half-flat-rafter period is very similar to the construction style of the current rafters of Muryangsujeon. However, the Muryangsujeon's eaves do not touch the corner rafter from the middle part. This seems to be a unique style, which is not common in China. In conclusion, the style of the side roof framework of Muryangsujeon at Buseoksa Temple is not of the China's southern regions, but of the northern regions of Tang(唐), Song(宋) and Liao(遼) Dynasties. And when considering the construction year and proportions of the middle front and side front on the same flat, this must be an ancient technique of the northeastern regions of Asia. Since it is likely that the structure of the side roof framework of Muryangsujeon at Buseoksa Temple has not been altered but is a unique style of hipped and gable roofs, this roof can serve as a good guide to restoring the hipped and garble roofs of the pre-Goyreo Dynasty period.

A study on the variant placement method of the traditional wooden architecture, rafter (전통 목조건축 서까래의 이형적(異形的) 배치 방식 연구)

  • Hong, Eun-ki;Chang, Hun-duck
    • Korean Journal of Heritage: History & Science
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    • v.48 no.4
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    • pp.110-125
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    • 2015
  • This study is objected to investigate the repairing method and the modification period of rafters via the transformation traces left in the superciliums, where repair process takes places frequently. This is the basic research of analyzing the architectural features of Deokkeori, one of the additional-rafter methods. Deokkeori method can be described as using Deokdori in the top section of Hayeon, and placement of Sangyeon above it. This method was started to be used since middle of the Joseon dynasty period(middle 18th Century) and mainly used at 19th Century to resist the transformation caused by repairing. It had been gradually developed from non-application stage to application stage including additional usage of complement. The architectural features of Deokkeori can be categorized into four. First, the usage of Deokdori to connect Sangyeon to the top section of Hayeon. It reduct the direct connection between Sangyoen and Hayeon, therefore give constructive benefits and prevent the downfall of the eaves by increasing the power which pressing the top section of Hayeon. Second, it gives the autonomy to the inside structure of ceiling by comprising it. By using Deokdori, the limit of top section's longitude was eliminated while also simplify the upper section by blocking the inside structures with ceiling. In addition, the complements occasionally seen in several buildings increase the power which pressing Hayeon. Third, the ceiling's slope has been changed to be concerned with Sangyeon, instead of Hayeon which was highly related with it before. The last factor is the thickness of rafters which used in Deokkeori. The diameter is thiner in Sangyeon than Hayeon.