Structural stability analysis of naturally ventilated polyhouses under different conditions

This research work on structural stability analysis of naturally ventilated polyhouses was carried out at the Department of Soil and Water Engineering, Punjab Agricultural University, Ludhiana. There were ۱۲ treatments which were combination of four different sizes of polyhouses i.e. ۵۶۰ (T۱-T۳); ۱,۰۰۸ (T۴-T۶); ۲,۰۸۰ (T۷-T۹); ۴,۰۰۰ m۲ (T۱۰-T۱۲), with three design wind speeds of ۱۰۰, ۱۵۰, and ۲۰۰ km h-۱, respectively. Stability analysis of truss members, columns, and foundation was carried out by considering dead loads, live loads and wind loads. Support reactions were computed on truss and column joints. Member forces were computed by using force method.  For every ۱۷ set of truss members, four members [two in compression (small arc) and two in tension (truss bracings)] failed in treatments with ۱۵۰ and ۲۰۰ km h-۱ wind speed, while in treatments with ۱۰۰ km h-۱ wind speed, two members [in compression, (small arc)] failed. Minimum structural GI pipe material requirement for structurally stable polyhouses was under treatment T۱ (۲,۴۰۷ kg) and the maximum was under treatment T۱۲ (۱۹,۵۵۰ kg).

Keywords:

Factor of safety , Force method , Protected cultivation technology , Wind speed