Effect of Rotational Components of Strong Ground Motions on the Response of Cooling Towers Based on Dense Array Data (A Case Study: Kazeron Cooling Tower)

The effect of earthquake rotational component (torsional and rocking ones) on the structures, has attracted the attention of many researchers in recent years. The impact of the rocking and torsional components of the ground motion, particularly on high-rise and height-wise irregular structures, is significant. In this paper, the rotational components of earthquake record were computed employing the acceleration gradient method, using the data obtained from a dense accelerometer array, and the behavior of the cooling towers under the influence of these rotational components was investigated. To this end, three distinct loading combinations were applied to the tower, and the results were examined and compared. The loading combinations include 1) three translational components of earthquake record, 2) applying rotational and translational components of the earthquake simultaneously, and 3) applying translational and rocking components concurrently. The response of the tower under the two latter loading combinations was compared with that of the first one. The results indicate that in the case of simultaneous action of translational and rocking components, displacements and support reactions, on average, increase by 5% in comparison with the case of applying solely translational component. Furthermore, including the torsional component, in addition to the rocking one, leads to a rise of nearly 6% in the displacements and supports reaction in comparison with the first loading combination results.