Experimental Study on the Ground Support Conditions of Pipe Ends in Single Span Pipe Greenhouse
2008
Lee, S.G. (Kyungpook National University, Daegu, Republic of Korea) | Lee, J.W. (Kyungpook National University, Daegu, Republic of Korea) | Kwak, C.S. (Institute of Renewable Energy and Environment, Daegu, Republic of Korea) | Lee, H.W. (Kyungpook National University, Daegu, Republic of Korea), E-mail: [email protected]
Single span pipe greenhouses (pipe houses) are widely used in Korea because these simple structures are suitable for construction by farmers thus reducing labor cost. However, these pipe houses are very weak and frequently damaged by heavy snow and strong wind. Pipe house is constructed by pipe fabricator, which is anchored to the ground by inserting each pipe end into ground to 30~40cm, so the ground support condition of pipe end is not clear for theoretical analysis on greenhouse structure. This study was carried out to find out the suitable ground support condition needed for structural analysis when pipe house was designed. The snow and wind loading tests on the actual size pipe house were conducted to measure the collapsing shape, displacement and strain. The experimental results were compared with the structural analysis results for 4 different ground support conditions of pipe ends(fixed at ground surface, hinged at ground surface, fixed under ground and hinged under ground). The pipe house under snow load was collapsed at the eaves as predicted, and the actual strain at the windward eave and ground support under wind load was larger than that under snow load. The displacement was the largest at the hinged support under ground, followed by the hinged at ground surface, the fixed under ground and then the fixed at ground surface independent of displacement direction and experimental loading condition. The experimental results agreed most closely with the results of theoretical analysis at the fixed condition under ground among 4 different ground support conditions. As the results, it was recommended that the pipe end support condition of single span pipe greenhouse was the fixed under ground for structural analysis.
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