RISK ASSESSMENT OF TRANSMISSION-LINE STRUCTURES UNDER SEVERE THUNDERSTORMS

To assess the collapse risk of transmission line structures subject to natural hazards, it is important to identify what hazard may cause th e structural collapse. In Australia and many other countries, a large proportion of failures of transmission line structures are caused by s evere thunderstorms. Because the wind loads generated by thunderstorms are not only random but time-variant as well, a time-dependent struct ural reliability approach for the risk assessment of transmission line structures is essential. However, a lack of appropriate stochastic mo dels for thunderstorm winds usually makes this kind of anaysis impossi ble. The intention of the paper is to propose a stochastic model that could realistically and accurately simulate wind loading due to severe thunderstorms. With the proposed thunderstorm model, the collapse ris k of transmission line structures under severe thunderstorms is assess ed numerically based on the computed failure probability of the struct ure.