Tornado-induced load distribution patterns and structural effects of a super large cooling tower

Abstract

The investigation was physically and numerically conducted aiming at wind load distribution patterns and structural effects of a super large reinforced concrete cooling tower (SLRCCT) subjected to tornado-like vortices, and the influence of swirl ratios and the central distances between the SLRCCT and the tornado vortex core (TVC) were studied. The tornado-induced loads on the SLRCCT were firstly obtained based on rigid pressure measurement tests. Subsequently, tornado-induced structural displacement and internal force responses were analysed. It is revealed that the swirl ratios and the central distance between the SLRCCT and TVC significantly determine the tornado-induced load distributions and structural performances of the SLRCCT. Finally, an equivalent static wind load mode suitable for tornado resistance design of the SLRCCTs was proposed. Specifically, an empirical polynomial was suggested to fit the critical net wind pressure coefficient envelope. Wind vibration factor based on the evaluation criterion of time-variant dynamic reinforcement ratios was proposed to consider the fluctuating effects of the tornado, and the maximum tangential speed could be used to estimate the intensity influence of the tornado acting on the SLRCCT. This paper aims to contribute to a better understanding of the wind-related effects and the wind-resistant design of the SLRCCTs exposed to disaster-causing non-synoptic winds, particularly tornadoes.