Pounding of seismically designed low-rise reinforced concrete frames

Abstract

Substantial damage to buildings from seismic pounding is a result of earthquakes in many urban areas. This study investigated the effects of pounding in low-rise buildings, which have been individually designed for seismic resistance, using a three-dimensional numerical model. The poundings between the heavier and lighter buildings were conducted in 4 cases under the floor to floor collision and zero separation gap, and the total heights of the buildings were varied. The ratio of the story mass between the heavier to the lighter buildings in all cases is 1.7. The results demonstrated that the heavier buildings were almost unaffected from the collision, and that seismic design without pounding consideration is acceptable. Nevertheless, the pounding had more influence on the lighter buildings. A significant increase of the inter-story drift and the story shear force can be found. At the top floor of the lighter building, the inter-story drift and the story shear force are increased in the range of 35-73% and 20-46%, respectively, compared with the no pounding events. In addition, severe damages at beam-column joints are found. Hence, the lighter buildings need special attention under a seismic pounding event.