Dynamic Response of Slender Vertical Structures Subjected to Thunderstorm Outflows

Abstract

This study examines the maximum alongwind dynamic response of slender vertical structures subjected to thunderstorms, comparing the induced maximum response with the one induced via synoptic events. Two real structures are considered as case studies: a lighting pole and a telecommunications tower. The comparison between thunderstorm- and synoptic-induced dynamic responses is performed through a critical analysis of three ratios characterizing the difference between the two phenomena: the reference wind speed, the mean wind profile, and the gust response factor. The comparison shows that the definition of the reference wind speed and the height of the nose tip of the thunderstorm mean wind profile are crucial for the maximum response, as well as for the dependence of the turbulence intensity on the roughness length. The results show that thunderstorms provide the design loading condition in most cases.

Keywords

• thunderstorm outflows
• extra-tropical cyclones
• gust response factor
• vertical slender structures
• wind engineering