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A Field Survey on the Structure and Maintenance Status of Pipe Framed Greenhouses (파이프 골조 온실의 구조 및 유지관리실태 조사분석)

  • 남상운
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.42 no.4
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    • pp.106-114
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    • 2000
  • An investigation was conducted to get the basic data for establishing maintenance strategy of pipe framed greenhouses. The contents of the investigation consisted of actual state of structures, maintenance status, meteorological disaster, and corrosion characteristics of pipe framework in greenhouses. the number of greenhouses investigated was 108 in total. Most multi-span greenhouses had narrower width and lower height than the standared 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. After about 7 years in grounds, 8 years in joints, 10 years in bending parts. and 13 years in columns. pipe surface was mostly rusted. Most weak parts in corrosion were pipes in contact with the ground, joints, roll-up shaft pipes, and pipes close to the gutter. Almost all of the greenhouse farmers didn't pay any attention to maintenance affair in a regular interval for pipe framed grenhouses. Many greenhouses have experienced the meteorologicla diaster such as uplift of foundation, partial or complete failure by the hyphoon and/or high winds.

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A Study on Effect of the Junction's Eccentricity for Buckling Characteristics of Single-Layer Latticed Dome (접합부 편심을 고려한 단층 래티스돔의 좌굴특성에 관한 연구)

  • Park, Sang-Hoon;Suk, Chang-Mok;Jung, Hwan-Mok;Kwon, Young-Hwan
    • Journal of Korean Association for Spatial Structures
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    • v.1 no.1 s.1
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    • pp.117-124
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    • 2001
  • In Single-layer latticed domes with rectangular network which is composed of ring of circumferential direction and rafter of longitudinal direction, that is, rib domes, if we use the cross-membered junction's method for the advantage in fabrication and construction, the eccentricity is occurred in the nodal point of crossing members. This paper is aimed at investigating the buckling characteristics for the effect of eccentricity according to rise-span ratios and distance of eccentricity. Analysis method is based on FEM dealing with the geometrically nonlinear deflection problems. The conclusion were given as follows: 1. The maximum decreasing ratio of buckling strength due to the junction's eccentricity is about 60% in models of this paper. 2. In the increasing ratio of buckling strength for rise-span ratio, that of Type 3 models is larger than that of type 2 models. On the other hand, that of Type 2 mode is larger than that of Type 3 for eccentricity-distance. 3. In the viewpoint of the value of buckling strength, that of Type 2 models is larger than that of type 3 models. The effect of the junction's rigidity on buckling strength is not great for overall models. Therefore if we use the cross-membered junction's method for the advantage in fabrication and construction, the method of Type 2 will have the great advantage of that of Type 3.

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A Study on the Creative Pattern Elements of Dancheong in Yeongnamnu Pavilion, Miryang (밀양 영남루 단청의 창의적 조형요소에 관한 연구)

  • Goo, Mi-Ju;Kwok, Dong-Hae;Lee, Ho-Yeol
    • Journal of architectural history
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    • v.25 no.6
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    • pp.81-88
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    • 2016
  • The purpose of this study is to inquire original design and character of dancheong in Yeongnamnu P avilion which features unusual portraits of twisting dragons and four heavenly creatures. Its artistic value and originality can be found in the portraits of four heavenly creatures which are painted on the interior seonjayeon(fan shape rafter) and in the unique design of crossbeam meoricho(flower decorations on each side of pillars). Yeongnamnu's crossbeam meoricho is janggu-meoricho type(meoricho with hourglass figure) with full-shape lotus and half-shape flower decorations. And it can be said that, dragon portrait painted on the border of lotus and flower decorations in green and yellow is a very unique style of dancheong, for the reason that it has scarcely been used before and ever since. The portrait of four heavenly creatures painted on each corner of seonjayeon is also found to be unique in design, for the reason that the design has rarely been used throughout history, with only two exceptions in mural tombs of Goguryeo and folding screen in Injeongjeon Hall of Changdeokgung P alace. With its unique and authentic feature along with its rarity in number, the portrait of four heavenly creatures painted on Yeongnamnu can be considered as quite symbolic and important.

A Study on the Occurrence and A change in the times of the Nemok-dori (내목도리의 발생과 시대적 변화에 관한 연구)

  • Heo, Kyoung-Do;Chung, Myung-Sup
    • Journal of architectural history
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    • v.29 no.1
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    • pp.39-49
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    • 2020
  • A dapo type bracket system which consists of chuganpo(柱間包) and chusangpo(柱上包) with a fake-beam adopted a nemok-dori member to cope with oemok-dori member in order to obtain balance between the outer-side and the inner-side of the bracket system. The middle part of the longest rater in the dapo system is supported by three points made by oemok-dori, jusim-dori and nemok-dori members and the area between the rafer supporting points forms a supporting area. The increase of rafter supporting points and supporting area leads to heightening the structural stability and the efficiency of load delivery. In the eave of dapo system the portion where the three supporting points formed by oemok-dori, jusim-dori and nemok-dori members shows as 33% in the early period, 71% in the middle period and 78% in the later period. On the contrary the portion where more than one of the three dori members were omitted shows as 67% in the early period, 29% in the middle period and 22% in the later period. This is the result of the increase of the number and the distance of steps in the dapo bracket system as time goes on. This is because the structural role of three supporting points becomes important as the increase of distance between the dori members leads to the increase of load which burdens on each dori member.

Full scale test and alnalytical evaluation on flexural behavior of tapered H-section beams with slender web

  • Lee, Seong Hui;Choi, Sung Mo;Lee, E.T.;Shim, Hyun Ju
    • Steel and Composite Structures
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    • v.8 no.5
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    • pp.389-402
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    • 2008
  • In December 2005, one(A) of the two pre-engineered warehouse buildings in the port of K City of Korea was completely destroyed and the other(B) was seriously damaged to be demolished. Over-loaded snow and unexpected blast of wind were the causes of the accident and destructive behavior was brittle fracture caused by web local buckling and lateral torsional buckling at the flange below rafter. However, the architectural design technology of today based on material non-linear method does not consider the tolerances to solve the problem of such brittle fracture. So, geometric non-linear evaluation which includes initial deformation, width-thickness ratio, web stiffener and unbraced length is required. This study evaluates the structural safety of 4 models in terms of width-thickness ratio and unbraced length using ANSYS 9.0 with parameters such as width-thickness ratio of web, existence/non-existence of stiffener and unbraced length. The purpose of this study is to analyze destructive mechanism of the above-mentioned two warehouse buildings and to provide ways to promote the safety of pre-engineered buildings.

Field Technique of Non-Educated Constructors in Timber Structure of Korean-Style Secondary Station(Gong-So) -Focused on the Sin-Sung and Su-Bun Secondary Stations- (한옥 공소의 목구조 방식에 나타난 민간 기술자의 현장기법 -천주교 신성공소와 장수천주교회 수분공소를 중심으로-)

  • Park, Kwang-Hyun;Kim, Tai-Young
    • Journal of the Korean Institute of Rural Architecture
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    • v.12 no.1
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    • pp.49-56
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    • 2010
  • This paper is aimed to clarify field technique of non-educated constructors in timber structure of korean-style secondary station(Gong-So) on the annex of catholic church. The main object of this study is Sin-Sung and Su-Bun secondary stations which post-lintel structure was 2high columns(Go-Ju) 5beams(Ryang) in Jeon-Buk area of Korea. We reached the following conclusion. Firstly, these secondary stations are required a lots of space for number of persons with the introduction of basilica plane. These plans have different intervals in the layout. Secondly, they constructed the holy space by using high columns(Nae-Jin-Go-Ju). The former problems of plan layout are sloved by reinforcement and replacement eaves and rafter of logitudinal. Thirdly, the elements showed the natural feature such as irregular wooden floor, arch-type head pentrating tie and a ceiling. In the end, we knew that non-educated constructor had found a way in the problem for accepting unreasonable work.

A Study on the Mulmae, Architectural Drawing Recorded on Uigwes - Focusing on the Possibility as a Cross-sectional Drawing - (의궤에 기록된 건축도(建築圖) 물매(勿每, 水每)에 관한 연구 - 단면도로서의 가능성을 중심으로 -)

  • Lee, Sang-Myeong
    • Journal of architectural history
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    • v.29 no.6
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    • pp.57-65
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    • 2020
  • This study covered the Mulmae, architectural drawing recorded on Yeonggeon-uigwes and Sanleung-uigwes during the late Joseon Dynasty. In uigwes, the term 'Mulmae' was used as a mixture until the 17th century, but from the 18th century, the term 'Mulmae(勿乙每, 勿每, 水每)' was unified into 'Mulmae(水每)'. The paper of the Mulmae was made to be used during the construction period by using a thick oil paper called Yudun. Four Yudun were connected, and its size was 197.4×141cm, which was rather large. The Yingzaofashi(營造法式) of Song Dynasty describes how to draw a longitudinal section on a scale of 1/10. The scale of 1/10 was the maximum when comparing the size of the Mulmae with the buildings in uigwes. A sectional drawing of Gongpo in Geunjeongjeon was drawn on a scale of 1/10. There is a testimony that a senior carpenter drew a cross-section on a scale of 1/10. Therefore, it was determined that the scale of the longitudinal section drawn on the Mulmae paper was 1/10. The term 'the Mulmae' was used equally by carpenter active in Japanese colonial era. The scope of the painting was clarified from pillar to rafter. Uigwes records that the Mulmae was made for wood processing. Through this, it can be understood that the Mulmae painted the entire structure as a longitudinal section.

Hygrothermal Performance Improvement Plan of Standard Model for Rural Housing and Wooden Housing (농촌주택 및 목조주택 표준모델 구조체의 습·열 환경 성능 개선 방안)

  • Yoo, Dong-Wan;Lee, Tae-Goo
    • Journal of the Korean Institute of Rural Architecture
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    • v.23 no.4
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    • pp.63-71
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    • 2021
  • The purpose of this study was to investigate whether the standard models for rural housing and wooden housing model have performance for hygrothermal and to propose a way of improvement relevant to hygrothermal performance for those models. All of the models to be analyzed were found to have some parts that were absent of stability in terms of performance for hygrothermal. In the process of analyzing the causes and proposing improvement measures, the following conclusions were derived. Fist, The exterior surface of the structure should be composed of a structure with good moisture permeability, and for the interior surface, a variable vapor retarder paper should be applied in consideration of the reverse condensation phenomenon in summer. Second, in terms of performance for hygrothermal, applications of external insulation plaster finish to the exterior wall or of ventilation method using a rafter vent on the roof should be avoided. Third, a rain screen method with a ventilation layer should be applied to the exterior wall, and a method of constructing ventilation layer separated from the insulation layer with a vapor retarder paper should be applied to the roof. Fourth, the application of insulation materials having capillary action, such as wood fiber insulation board or cellulose insulation board, contributes to more stable performance for hygrothermal.

Evaluation of Structural Stability of a Simple-typed Cultivation Facility for Growing Pleurotus ostreatus (간이 느타리재배사의 구조 안전성 평가)

  • Yum, Sung-Hyun;Yun, Nam-Kyu;Kim, Chul-Soo
    • Journal of Bio-Environment Control
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    • v.17 no.3
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    • pp.181-187
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    • 2008
  • The structural stability of a simple-typed cultivation facility with a width of 5.6 m for growing Pleurotus ostreatus was analyzed by modeling the facility as three-dimensional steel frames. The computation was done by using the finite element analysis program, ANSYS and the criterion of determining structural stability was based on the allowable stress design (ASD). The computational results showed that the structure with a straight-typed bed column was more stable than those with other types of bed columns against snow depth but there was little difference against wind velocity. As results, the interval of rafter had a more influence on safety wind velocity than that of bed column, while the interval of bed column was more important to safety snow depth. Finally the bed column against buckling was stable in all cases considered in this paper.

Structural Performance Evaluation of End-plate Connections According to Constructional Quality in P.E.B System (P.E.B 시스템에서 시공상태에 따른 엔드플레이트 접합부의 구조성능평가)

  • Lee, Eun-Taik
    • Journal of Korean Society of Steel Construction
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    • v.24 no.4
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    • pp.461-468
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    • 2012
  • P.E.B (Pre-Engineering Building) system means an economical system, which designs and uses optimal section proportion of tapered members according to the magnitude of bending moment. However, it is hard to adjust the friction type bolted joint in the joint of tapered member in the P.E.B system. End-plate connection is mainly used in this system due to that difficulty. Because P.E.B system has end-plate vertical defacts by heat welding deformation, a gap between end-plates and rafter or rib can be observed. In this study, an examination of construction stability was throughly performed and analyzed by the investigation of permissible internal force of bolts in end-plate connections under the bending moment using the end-plate's initial connection-defect (gap).