DAMAGE ANALYSIS OF HIGH-RISE BUILDING STRUCTURES WITH ASYMMETRIC VERTICAL SETBACKS UNDER RARE EARTHQUAKE ACTION

Concrete filled steel tube frame-core wall-outrigger truss structure system is adopted for buildings with asymmetric vertical setbacks. The seismic performance and damage distribution of the structures were analyzed by using elastic-plastic analysis under rare earthquake action. A three-dimensional numerical model was established, the influence of earthquake amplitude on the damage distribution of irregular high-rise structures was studied. The results indicated that the performance state of the core shear wall was slight damage, and earthquake energy could be dissipated by coupling beams entering to the plastic damage state. The outrigger floor and adjacent upper floors of high-rise structures with asymmetric vertical setbacks had severe damage, the shear wall with obvious damage should be reinforced. The floor slabs where the outriggers were located had a moderate damage caused by horizontal shear action, which should be strengthened. Damage development was more obvious under rare earthquake action than that of fortification earthquake action, but the location and trend of structural damage were more consistent. In conclusion, the seismic weak parts of high-rise structures with symmetric vertical setbacks should be analyzed based on the damage analysis under rare earthquake action.