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http://dx.doi.org/10.12791/KSBEC.2015.24.3.226

Comparison and Decision of Exposure Coefficient for Calculation of Snow Load on Greenhouse Structure  

Jung, Seung-Hyeon (Department of Agricultural Eng., Kyungpook National Univ.)
Yoon, Jae-Sub (Gyeongbuk Regional Head Office, Korea Rural Community Corp.)
Lee, Jong-Won (Institute Agricultural Science & Technology, Kyungpook National University)
Lee, Hyun-Woo (Department of Agricultural Eng., Kyungpook National Univ.)
Publication Information
Journal of Bio-Environment Control / v.24, no.3, 2015 , pp. 226-234 More about this Journal
Abstract
To provide the data necessary to determine exposure coefficients used for calculating the snow load acting on a greenhouse, we compared the exposure coefficients in the greenhouse structure design standards for various countries. We determined the exposure coefficient for each region and tried to improve on the method used to decide it. Our results are as follows: After comparing the exposure coefficients in the standards of various countries, we could determine that the main factors affecting the exposure coefficient were terrain roughness, wind speed, and whether a windbreak was present. On comparing national standards, the exposure coefficients could be divided into three groups: exposure coefficients of 0.8(0.9) for areas with strong winds, 1.0(1.1) for partially exposed areas, and 1.2 for areas with dense windbreaks. After analyzing the exposure coefficients for 94 areas in South Korea according to the ISO4355 standard, all of the areas had two coefficients (1.0 and 0.8), except Daegwallyeong (0.5) and Yeosu (0.6), which had one coefficient each. In South Korea, the probability of snow is greater inland than in coastal areas and there are fewer days with a maximum wind velocity > $5m{\cdot}s^{-1}$ inland. When determining the exposure coefficients in South Korea, we can subdivide the country into three regions: coastal areas with strong winds have an exposure coefficient of 0.8; inland areas have a coefficient of 1.0; and areas with dense windbreaks have an exposure coefficient of 1.2. Further research that considers the number of days with a wind velocity > $5m{\cdot}s^{-1}$ as the threshold wind speed is needed before we can make specific recommendations for the exposure coefficient for different regions.
Keywords
greenhouse structure design standard; International Organization for Standardization; snow depth; temperature; wind velocity;
Citations & Related Records
Times Cited By KSCI : 7  (Citation Analysis)
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1 Architectural Institute of Japan (AIJ). 2004. Recommendations for loads on buildings.
2 Architectural Institute of Korea (AIK). 2009. Korean Building Code and Commentary (in Korean).
3 Choi, M.G., S.W. Yun, H.T. Kim, S.Y. Lee and Y.C. Yoon. 2014a. Field survey on the maintenance status of greenhouses in Korea. Protected Horticulture and Plant Factory 23(2):148-157 (in Korean).   DOI
4 Choi, M.G., S.W. Yun, H.T. Kim, S.Y. Lee and Y.C. Yoon. 2014b. Current status on the greenhouse foundation. Journal of Agriculture & Life Science 48(3):251-260 (in Korean).   DOI
5 International Organization for Standardization (ISO). 1998. ISO 4355 Bases for design on structures - determination of snow loads on roofs. 2nd ed. Geneve: International Organization for Standardization
6 Japan Greenhouse Horticulture Association (JGHA), 1997. Standard for structural safety of greenhouse. Tokyo: Japan Greenhouse Horticulture Association (in Japanese).
7 Jung, S.H., H.W. Lee, J.W. Lee, W.H. Na and S.Y. Lee. 2014a. Comparison of Wind Pressure Calculation Formula for Greenhouse Structure Design in Some Nations Standard. Proceedings of the Korean Society for Bio-Environment Control Conference 23(1):189-190 (in Korean).
8 Jung, S.H., H.W. Lee, J.W. Lee, W.H. Na and S.Y. Lee. 2014b. Comparison of snow loads calculation standards for greenhouse structure design in Some Nations. Proceedings of the Korean Society for Bio-Environment Control Conference 23(2):169-170 (in Korean).
9 Jung, S.H., H.W. Lee, J.W. Lee and S.Y. Lee. 2015. Analysis of wind velocity profile for calculation of wind pressure on greenhouse. Protected Horticulture and Plant Factory, Accepted (in Korean).
10 Kim, R.U., D.W. Kim, K.C. Ryu, K.S. Kwon, and I.B. Lee. 2014. Estimation of wind pressure coefficients on even-span greenhouse built in reclaimed land according to roof slope using wind tunnel. Protected Horticulture and Plant Factory. 23(4):269-280 (in Korean).   DOI
11 Kind, RJ. 1981. Handbook of snow: principles, processes, management and use. Snow drifting. Oxford: Pergamon Press. 338-59.
12 Lee, B.G., S.W. Yun, M.K. Choi, S.Y. Lee, S.D. Moon, C. Yu and Y.C. Yoon. 2014. Uplift bearing capacity of spiral steel peg for the single span greenhouse. Protected Horticulture and Plant Factory. 23(2):109-115 (in Korean).   DOI
13 Li, L. and Pomeroy, JW. 1997. Estimates of threshold wind speeds for snow transport using meteorological data. Journal of Applied Meteorology 36:205-13.   DOI
14 Mellor, M. 1965. Cold Regions Science and Engineering. US Army Material Command, Cold Regions Research & Engineering Laboratory. Part III, Section A3c, Blowing snow.
15 Nam, S.W., and Y.S. Kim. 2009. Actual state of structures and environmental control facilities for tomato greenhouses in Chungnam region. Jour. Agri. Sci. 36(1):73-85 (in Korea).
16 Meloysund V., K.R. Liso, H.O. Hygen, K.V. Hoiseth and H.O. Hygen. 2007. Effects of wind exposure on roof snow loads. Building and Environment 42:3726-3736.   DOI
17 Ministry of Agriculture, Food and Rural Affairs (MAFRA). 1999. Greenhouse structure design standards and explanations (in Korean).
18 Ministry for Food, Agriculture, Forestry and Fisheries(MIFAFF), Rural Development Administration(RDA). 2010. Designated notice of standards to endure disaster for horticultural and special facilities (in Korean).
19 National Disaster Information Center. Retrieved from http://www.safekorea.go.kr
20 National Greenhouse Manufactures Association (NGMA). 2004. Structural Design Manual. ed. NGMA, PA, USA.
21 Netherlands Standardization Institut(NEN). 2004. Greenhouses : Design and construction - part1 : commercial production greenhouses
22 Otstavnov, VA. and Rosenberg, LS. 1989. Consideration of wind effect in standardization of snow load. A multidisciplinary approach to snow engineering: first international engineering foundation, US Army Corps of Engineers Cold Regions 8387 89(6):256-63.
23 Rural Development Corporation(RDC). 1995. Greenhouse structural requirements. ed. RDC, Uiwang, Korea (in Korean).
24 Rural Development Adminstration(RDA). 2000. Agricultural disasters countermeasure and its technology. ed. RDA, Jeonju, Korea (in Korean).
25 Ryu, H.R., I.H. Yu, M.W. Cho, and Y.C. Um. 2009. Structural reinforcement methods and structural safety analysis for the elevated eaves height 1-2W type plastic greenhouse. J. Bio-Env. Cont. 18(3):192-199 (in Korean).
26 Rural Development Administration(RDA). 2005. Damage aspects and countermeasure of horticultural facilities by meteorological disasters. ed. RDA, Jeonju, Korea (in Korean).
27 Rural Development Adminstration(RDA). 2007. A guide book for meteorological disasters reduction of agricultural facilities. ed. RDA, Jeonju, Korea (in Korean).
28 Rural Development Administration(RDA). 2009. The workshop for Reduction countermeasure of meteorological disasters for horticultural and special facilities. ed. RDA, Jeonju, Korea (in Korean).
29 Shu, W.M., M.K. Choi, Y.H. Bae, J.W. Lee, and Y.C. Yoon. 2008. Structural safety analysis of a modified 1-2W type greenhouse enhanced for culturing paprika. J. Bio-Env. Cont. 17(3):197-203 (in Korean).
30 Yu, I.H., E.H. Lee, M.W. Cho, H.R. Ryu, and Y.C. Kim. 2012. Development of multi-span plastic greenhouse for tomato cultivation. J. Bio-Env. Cont. 21(4):428-436 (in Korean).   DOI