Structural Safety Changes and Reinforcement Effect of Raising the Height of Korean Plastic Greenhouses

This study evaluates the reliability-based structural safety of a plastic greenhouse design and analyzes how the level of safety changes when the height of a plastic greenhouse is elevated. We also examine the effects of reinforcement on safety using three different reinforcement methods to address the structural instability caused by increasing the height of plastic greenhouses. When the height of a 1–2W type plastic greenhouse was raised from 2.8 m to 4.5 m, the maximum bending stress in the windbreak wall member doubled, which in turn doubled the safety risk. Theoretically, the maximum height without structural reinforcement is 3.6m, and reinforcement is necessary when the height reaches 4.5 m. After conducting a structural reliability analysis using the average and standard deviation of the wind load, the existing 2.8 m height had a failure probability of 10%, and when raised to 4.5 m, the probability of failure (PF) increased by approximately 79%. The analysis results showed that safety increased by 2.0 to 2.5 times with reinforcement according to the three reinforcement methods tested here, reducing the probability of failure to 10%. Additionally, the stress in the windbreak wall member under the highest level of stress decreased rapidly by 16% to 26%, significantly contributing to the safety of the windbreak wall.