• 농업과학연구
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• 제38권3호
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• pp.505-512
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• 2011

Structural characteristics for standard models of single-span plastic greenhouse in Korea and high tunnels in North America were analyzed, and comparative analysis for greenhouse environments measuring in Korean farmhouse and Rutgers high tunnel was carried out to find structural and environmental improvements of single-span plastic greenhouses that occupy most of Korean greenhouse. Widths of high tunnels are similar to single-span plastic greenhouses but their heights are high comparatively and their side heights are fairly higher than single-span plastic greenhouses specially. Rafters, which are main frames, section sizes of high tunnels are bigger and their intervals are wider than single-span plastic greenhouses. Relative bending resistances compared with representative Korean greenhouse were analyzed by 0.92 to 1.42 in single-span plastic greenhouses, and 1.38 to 2.96 in high tunnels. Frame ratios of single-span plastic greenhouses were 6.8 to 8.6%, and those of high tunnels were 5.5 to 8.7%. We analyzed air temperatures and solar radiations measured in single-span plastic greenhouse and high tunnel on clear days in late March. There were outside temperatures in generally similar range, and judging by rise of indoor temperatures, ventilation performance of high tunnel is more excellent than single-span plastic greenhouse. Solar radiations of two areas were no big difference but light transmittance of high tunnel was a little bit higher than single-span plastic greenhouse. Single-span plastic greenhouses are disadvantageous in environmental managements such as ventilation performance and light transmittance because distance between greenhouses is too narrow and length of greenhouse is too long compared to high tunnels. To get the environmental improvement effects as well as to increase the structural resistance of single-span plastic greenhouses are achievable by widening the width of greenhouse in possible range, widening the space between rafters, and enlarging the section size of rafters. Also, we need to secure enough distance between greenhouses and to restrict the length of greenhouse by maximum 50 m in order to improve the ventilation performance and the light transmittance.

• 한국농공학회지
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• 제29권3호
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• pp.113-124
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• 1987

The objective of this study was to disclose the problem of structural safety and the state of utilization of standard types of plastic film house through investigation of actural state of plastic greenhouses for the southern part of the Korean peninsula. And also, the application method of standard types were proposed. The results obtained are summarized as follows 1. Plastic film houses investigated were not designed by the structural design conditions of loads and materials. 2.The construction method of greenhouses was not standardized. 3.Single type of standard greenhouses was nearly used and double types were applied to the standard type. 4.The standard frames of plastic film house were appeared to have structural lack of stability at the design snow and wind loads for most regions. 5.Safety snow depths and safety wind velocities were proposed for the frame intervals and pipe diameters of standard greenhouses.

• 한국농공학회논문집
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• 제66권1호
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• pp.39-48
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• 2024

Plastic greenhouses are simple structures consisting of lightweight materials such as steel pipes and polyvinyl chloride. However, serious damage occurs due to heavy winds and typhoon every year. To prevent a collapse of structural members, the Ministry of Agriculture and Rural Development has distributed plans and specifications for disaster-resistant standards. Despite these efforts, more than 50% of greenhouses still do not satisfy the disaster-resistant standards. Among the greenhouses that do not meet these standards, 85% are single-span greenhouses proposed 20 years ago. Consequently, there is a need to evaluate the safety of wind loads for the single-span greenhouse. Unfortunately, there are no design specifications for the greenhouses under wind loads. Therefore, a Korean design standard (KDS) has been utilized. KDS is defined with reference to wind speeds occurring once every 500 years, raising concerns about potential overdesign when considering the durability of plastic greenhouses. To address this, the modified wind load, considering the durability of the plastic greenhouse, was calculated, and a safety evaluation was conducted for sigle G-type plastic greenhouse. It was observed that the moment acting on the windward surface was substantial, and there was a risk of the foundation being pulled out if the basic wind speed exceeded 32 m/s. In terms of the combination strength ratio, it was less than 1.0 only on the leeward side when the basic wind speed was 24 m/s and 26 m/s. However, in all other cases, it exceeded 1.0, indicating an unsafe condition and highlighting the necessity for reinforcement.

• 한국농공학회지
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• 제44권4호
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• pp.107-113
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• 2002

The pipe framed and arch shape plastic greenhouse, which is the most popular greenhouse in Korea, is relatively weak in snowdrift. Reinforcement of rigid frame or column is required to reduce the damage from heavy snow in this type. But additional rigid frames or columns decrease light transmissivity or workability, and increase construction cost. So it is desirable to prepare some temporary poles and to install them when the warning of heavy snow is announced. This study was carried out to develop the temporary pole supporting system using galvanized steel pipes for plastic housing and to evaluate the safe snow load on a temporary pole. A pipe connector, which is inserted in the top of pipe used in the temporary pole and supports the center purline, was designed and manufactured to be able to carry the upper loads safely. And a bearing plate was safely designed and manufactured in order to carry the loads acting on it to the ground. When temporary poles of ${\phi}$ 25 pipe are installed at 2.4m interval, it shows that the single span plastic greenhouses with 5~7 m width are able to support the additional snow depth of 13.9~25.3 cm beyond the snow load supported by main frame.

• 농업과학연구
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• 제41권3호
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• pp.251-258
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• 2014

In order to set up the basic environmental control systems which the new concept greenhouses have to equip, greenhouse characteristics, environmental management and control systems in domestic glasshouses and plastic houses were investigated and analyzed comparatively. Survey results on the width, length, eaves height, and the number of spans etc. showed that glasshouses were bigger than plastic houses significantly. New concept greenhouses claim to be plastic houses, but it will be reasonable to follow the specifications of the glasshouse. Specifications to be applied to new concept greenhouses were proposed as follows; hot water heating systems, aluminum screens as the thermal curtain, evaporative cooling systems, roof vents on the ridge, circulation fans, $CO_2$ enrichment, hydroponic systems, and automatic irrigation control systems. Environmental measurement systems for the indoor and outdoor temperature, humidity, light, wind speed and indoor $CO_2$ concentration have to be fully equipped. The automatic control system has to be as a complex environmental control system, not a single item control system. Also, for stable dissemination, domestically producing complete greenhouse control system should be made as soon as possible.

• Current Research on Agriculture and Life Sciences
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• 제31권4호
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• pp.280-285
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• 2013

국내에 설치되어 있는 원예시설 중 가장 많은 면적을 차지하고 있는 단동비닐하우스의 기상재해로 인한 피해를 경감시킬 수 있는 모델 개발에 필요한 기초자료를 제공하고자 재배작물별로 대표적인 온실규격를 선정하여 안전풍속과 적설심을 구한 후 재현기간 8년에 해당하는 지역의 설계풍속 및 적설심과 비교하여 온실의 구조 안전성을 분석한 결과를 요약하면 다음과 같다. 1. 재배작물별 대표온실에 단위풍하중을 적용한 결과, 최대 단면력은 과채류, 근채류, 엽채류 온실 순으로 크게 나타났으며 재배작물별 서까래 간격을 고려한 안전풍속은 엽채류 온실이 17.7 m/s, 과채류 온실이 20.2 m/s, 근채류 온실이 22.3 m/s로 나타나 지역별 8년 빈도의 설계풍하중과 비교하였을 때 홍천, 이천, 성주지역을 제외하고는 대부분의 지역에 있어서 불안전한 것으로 나타났다. 2. 재배작물별 대표온실에 단위 적설하중을 적용한 결과, 근채류 온실의 최대 단면력이 가장 크게 나타났으나 재배작물별 서까래 간격을 고려한 안전적설심은 엽채류 온실이 8.8 cm, 과채류 온실이 9.4 cm, 근채류 온실이 11.8 cm인 것으로 나타났다. 이러한 결과를 지역별 8년 빈도의 적설하중과 비교하였을 때 경남지역 일부를 제외하고는 대부분의 지역에 있어서 불안전한 것으로 분석되었다. 3. 재배작물별 대표 온실의 안전풍속과 적설심에 대하여 구조물에 발생하는 최대 인발력은 12.7~15.1 kgf/개소, 최대 연직하중은 20.6~21.7 kgf/개소로 나타나 기초는 안전한 것으로 분석되었으나 안전풍속과 안전적설심이 매우 작기 때문에 폭설이나 강풍에 대비한 보강이 필요한 것으로 나타났다. 4. 재배작물별 대표온실의 안전풍속과 적설심을 증가시키기 위해서는 서까래 간격을 감소시키거나 부재의 단면 치수를 증가시키는 등의 보강대책이 필요한 것으로 나타났다.

• 한국농촌건축학회논문집
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• 제22권1호
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• pp.13-20
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• 2020

As the number of plastic greenhouses has increased in Korea, the damage from typhoons and snow has also increased. Structural design codes for a disaster-resistant plastic greenhouse have been revised over the last few decades. In particular, the revised code draft in 2017 have changed in many ways compared to the 1995 code. Nevertheless, There is no study of the effect of new design code on plastic greenhouse. Therefore, this study evaluated the safety of plastic greenhouse against wind load according to 1995 and 2017 codes for type 1 houses, which is most commonly built in Jeju, through comparing the analytical results of plastic greenhouses designed by 1995 code and 2017 code draft. The results are as follows. (1) The uplift load due to the negative pressure on the roof of the plastic greenhouse increased significantly in 2017 code draft. (2) Since the existing members could not meet the design requirements, the rafters had to be replaced with members of the same cross-section as the columns. (3) Due to excessive lifting, measures were also needed to prevent lifting at the foundation of the plastic greenhouse.

• 생물환경조절학회지
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• 제22권4호
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• pp.371-377
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• 2013

고추 수급 안정대책의 일환으로 정부에서는 2012년부터 고추 비가림시설 지원 사업을 실시하고 있지만 현재 농가에 보급되고 있는 단동 비닐하우스는 측고가 낮아 고추 비가림재배에 부적합한 면이 있다. 본 연구에서는 고추 재배에 적합한 규격을 가지면서 구조적으로도 안전한 고추 비가림재배용 단동 비닐하우스를 개발하고자 하였다. 전국 56개 고추 비가림재배 농가를 대상으로 비닐하우스 구조실태 및 구조개선 희망사항을 조사하여 비닐하우스 폭과 높이를 설정하였다. 현재 운용중인 비닐하우스의 폭은 7m 미만이 53%를, 측고는 1.5m 이하가 64%로 가장 높은 비율을 차지하였다. 희망하는 하우스의 폭은 7.0m, 측고는 2.0m를 선호하는 농가가 가장 많아서 이 규격으로 결정하였다. 서까래 파이프 규격을 다양하게 변화시켜가면서 구조안전성을 분석한 후 골조율과 설치비 등을 고려하여 5종의 모델을 제시하였다. 12-고추-1형은 ${\emptyset}42.2{\times}2.1t$의 서까래 파이프를 90cm 간격, 12-고추-2형부터 5형은 ${\emptyset}31.8{\times}1.5t$의 서까래 파이프를 각각 60cm, 70cm, 80cm 및 90cm 간격으로 설치하는 모델이다. 농림수산식품부 고시 10-단동-3형과 비교하여 12-고추-2형의 경제성을 분석한 결과, $672m^2$ 면적의 하우스 1동 기준으로 약 120만원의 소득 증가가 있는 것으로 나타났다.

• 생물환경조절학회지
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• 제26권1호
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• pp.27-34
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• 2017

본 연구에서는 간척지에서 플라스틱 온실의 기초안전성을 평가하기 위하여 강재 나선말뚝기초를 갖는 폭 6m 연동하우스 1개동과 강재 나선말뚝기초와 파이프줄기초를 각각 적용한 폭 8.2m 단동하우스 2개동을 SPT N값이 2인 간척지 시험포장에 설치하여 플라스틱 온실의 인발량 및 침하량을 측정하였다. 또한 플라스틱 온실에 적용된 나선말뚝기초 3종(${\phi}50$, ${\phi}75$ 및 ${\phi}100$)을 인근의 간척지 시험포장에 설치하여 인발저항특성을 시험하였다. 평가 기간 중 플라스틱 온실의 수직변위 움직임이 관측되었지만 온실의 규모와 비교하여 그 변위는 무시할만한 수준이었다. 평가 기간 중의 최대 수직변위는 나선말뚝 기초를 적용한 연동하우스의 경우 +9.0mm(인발)~-11.5mm(침하), 나선말뚝기초를 적용한 단동하우스의 경우 +1.3mm~-7.7mm, 파이프줄기초를 적용한 단동하우스의 경우 +0.9mm~-11.2mm로 나타났다. 나선말뚝기초의 허용인발력은 모두 극한하중 판정기준에 의해 판단할 수 있었으며 ${\phi}50mm$, ${\phi}75$와 ${\phi}100$ 나선말뚝기초의 최종 허용인발력은 각각 0.40kN, 1.0kN과 2.5kN으로 산정할 수 있었다. 평가기간 중 나선말뚝기초를 적용한 플라스틱 온실의 기초안전성을 최종적으로 판단하기에는 다소 무리가 있다고 판단되나 강재 나선말뚝기초를 간척지 플라스틱 온실의 기초로 사용하더라도 큰 문제는 없을 것으로 판단되었다.

• 한국지역사회생활과학회지
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• 제21권4호
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• pp.551-558
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• 2010

It is a normal circumstance to have high temperature and high humidity in Greenhouses even though these climates are changed by the area, season, climates, the size of the greenhouse, and the crops being raised. Workers in the greenhouses have complained about their uncomfortable work environment and discomfort from the hot conditions, including sunburn. The farmers' ailments are not significantly different between those working in the in greenhouses and those working in the fields. The Farmers' syndrome was almost two times higher for women than those of men for greenhouse workers. This study was developed for functional fatigue clothes for plastic greenhouses which are known for high temperatures and humidity. The ergonomic function and thermal comforts of fatigue clothes were evaluated in the climatic chamber($30.0^{\circ}C$, 70.0%R.H.). The current fatigue clothes which are made of cotton or nylon were purchased at the market. The developed clothes are made of highly absorbent and high speed drying polyester. And these fabrics have excellent elasticity. In this study, the functional fatigue clothes were designed with longsleeved sport shirts and Full length pants. Tre, Tsk, Hcl, HR and the personal subjective sensations such as heat, humidity, and comfortableness were significantly lower when subjects wore the developed clothes made with polyester than the previous attire.