Reliability assessment for hybrid solar tower under near-fault pulse-like ground motions using Kriging surrogate and subset simulation

Abstract

Concentrated solar towers are commonly designed as high-rise hybrid structures, which exhibit properties of non-uniform mass and rigidity along the height of the tower, and consequently are vulnerable to strong seismic ground motions. This study presents a comprehensive analysis of the seismic performance of a hybrid solar tower, which is one of the tallest hybrid solar towers in the world. The hybrid solar tower includes a reinforced concrete tube at the bottom and a steel-truss tube at the top and is subjected to near-fault pulse-like ground motions. A simulation technique that utilizes the stochastic point-source model and a velocity pulse model was introduced to generate stochastic pulse-like ground motions. The stochastic response of the hybrid solar tower to near-fault pulse-like ground motions was computed to estimate the tower’s reliability. To enhance the efficiency of reliability estimation, an algorithm combining the Kriging surrogate and subset simulation (K-SS) was presented. The aggregate response of the tower was found to be significantly more damaging over the border of the reinforced concrete tube and the steel-truss tube than below the border. The study found that the hybrid solar tower has a reliability of 90.53% when subjected to stochastic near-fault pulse-like ground motions with a peak ground acceleration of 0.62 g. The findings of this study contribute to the understanding of the seismic performance of high-rise hybrid solar towers under near-fault pulse-like ground motions.