Effect of High Intensity Wind Loads on Steel Poles Transmission Lines
摘要
The vulnerability of transmission lines to high intensity wind (HIW) loads, such as downbursts and tornadoes, has been realized through several transmission lines failures around the world. Transmission poles are commonly used in urban and suburban high-voltage transmission lines. However, transmission poles can be more vulnerable to HIW loads than lattice transmission towers due to their limited redundancy. The study aims to investigate the sensitivity of steel poles transmission lines to downbursts and tornadoes. The critical load cases are determined by equating the peak straining actions due to HIW loads, to those obtained due to the synoptic wind and ice loads cases. HIW loads cases are calculated using the new provisions recently incorporated in ASCE 74 (2020) guidelines. The results of this study provide the magnitude of HIW loads beyond which the considered transmission poles are not safe, if they were designed to withstand only synoptic wind and ice loads cases without a margin of safety.