The random earthquake response and optimization analysis of parallel isolated high-rise structure

We research the random response of parallel isolated high-rise structure under stable random excitation by pseudo excitation approach. The isolation layer is composition of laminated rubber bearings, sliding bearings and viscous dampers. The structure is modeled as non-linear damped system based on equivalent linear parameters, and adopts acceleration power spectral density function which can model long period ground motion well. The displacement of isolation layer and inter-story displacement of superstructure are used as the ultimate value to establish the performance equation. The failure probability is calculated using first-order reliability method (FORM), and the total reliability of structure is derived by regarding the stories to be of series relation. With a 25-story isolated structure in high earthquake-intensity area in Jiangsu used as a numerical example, we can obtain the statistic of the main response of isolation layer and superstructure, failure probability of every layer and reliability of structure system by seismic response analysis. The results contrive that the dynamic reliability of structure will be increased after using parallel isolated supports in high-rise building.