Elasto-plastic time-history analysis on multi-tower isolated structure with an enlarged base

Seismic response analysis under rare earthquake of multi-tower isolated structure with an enlarged base was carried out using elastic-plastic time-history method. Plastic deformation, story displacement and story acceleration were all included. The results show that plastic deformation is not highly developed and the structure can be used after simple repairation. Plastic hinges appear all at the end of frame beams, and no one is found at the end of frame columns. Story displacement is centralized at isolation layer, and story drift is small on superstructure. Story acceleration is reduced significantly.