Probabilistic Seismic Demand Analysis and Seismic Fragility Analysis of High‐Rise Structures Based on the Cloud Method

With the proposal of the probabilistic framework for performance‐based earthquake engineering, seismic fragility analysis has attracted widespread attention. It quantitatively evaluates the seismic performance of structures from a probabilistic perspective and macroscopically reflects the relationship between ground motions effects and the degree of structural damage. With the rapid economic development and accelerated urbanization process, the number of high‐rise structures has been increasing steadily. Given the uncontrollable consequences of seismic damage to high‐rise structures, conducting seismic fragility analysis on these structures carries significant engineering value. In this study, with reference to the division of performance levels and the determination of quantitative indicators specified in Chinese National Standards and Chinese Association Standards, the limit states of high‐rise structures under ground motion are classified into five levels. The software SAUSAGE is employed to establish nonlinear dynamic analysis models for a 141.3‐m‐high shear wall structure and a 199.7‐m‐high frame‐core wall structure. After fully accounting for the uncertainty of ground motions, probabilistic seismic demand analysis and seismic fragility analysis based on the cloud method are conducted on the high‐rise structures. The probabilities of the high‐rise structures exceeding the five limit states under three seismic levels corresponding to different seismic fortification intensities are obtained. The results indicate that (a) the probabilistic seismic demand analysis and seismic fragility analysis based on the cloud method can provide a robust scientific basis for the seismic performance evaluation of high‐rise structures and that (b) high‐rise structures designed in accordance with Chinese national standards can meet the three‐level seismic fortification objectives of “no damage under frequent earthquake, repairable under fortification intensity earthquake, and no collapse under rare earthquake.”