Design and Analysis of Transmission Tower Under Wind Loading

Transmission towers play an important role in power sector and in human life. Structural design of lattice transmission tower is a crucial topic among the civil engineers. Various researches have been done on steel tower response to wind loading. Wind loads are randomly applied dynamic loads which are a major concern in case of transmission towers which are at high altitude from the ground level. In this paper, a 33 kV double circuit transmission tower with a height of 21 m has been modeled. The tower is designed having a square base width of 6 m situated in wind zone—IV having a basic wind speed of 50 m/s. The model has been analyzed manually as per the IS code. The design of the steel structure is based on the Indian Standard Code IS 800-2007 under limit state design which is the revised version of the code. The design wind force on each component of the tower has been calculated according to IS 875 (Part 3): 1987. In this paper, the analysis method used for calculation of axial forces is considered to be linear in behavior with two-dimensional approaches and the structure is considered to be determinate by ignoring the horizontal members. The results obtained have been further validated using STAAD-Pro v8i software in order to compute the accuracy of calculation. Temperature load is an important parameter in the design of transmission tower which has been considered. The sag tension for different ambient temperatures has been determined under different sag scenarios of the conductors.