Seismic fragility assessment of traditional air-cooled support structure and air-cooled support energy dissipation structure based on IDA method

In this paper, the effectiveness of the modeling method is verified by the finite element analysis of the preliminary test. Three finite element models of traditional air-cooled support structure, 'large diameter RC tubular columns + LBRB' energy dissipation structure and 'small diameter RC tubular columns + LBRB' energy dissipation structure are established. Based on IDA method, the fragility of air-cooled support structure and energy dissipation structures is studied. The study shows that the addition of LBRB can effectively improve the horizontal-torsional coupling phenomenon of the structure, improve the ductility and seismic performance, and reduce the failure probability of the structure. Adding LBRBs and reducing the diameter of RC tubular columns can play the role of LBRB energy dissipation to a greater extent, so that the structure can obtain stronger anticollapse capacity and better economy, which is more conducive to the realization of seismic performance-based fortification goal. It is suggested that three-dimensional ground motion input should be used for fragility analysis. If the dimension of ground motion input is reduced, the assessment results will be biased to danger.