Effects of spatial variability of ground motions on collapse behaviour of buildings

Abstract

The seismic damage simulation of buildings has become a research focus because of the rapid urbanisation and the increase in the building density. However, there is no consensus regarding whether the spatial variability of ground motions at the local sites must be considered in collapse simulations. Thus, in the present study, a numerical model based on the finite element method that can effectively predict the collapse behaviour of reinforced concrete buildings is developed. Then, field ground motion records are selected from the measurement database. Finally, a building neighbourhood comprising four typical three-storey reinforced concrete frame structures is established as a numerical example, and the effects of the spatial variability and intensity of ground motions on the structural response and collapse behaviour of buildings are comprehensively investigated. The results indicate that the spatial variability of the ground motions significantly affects the structural responses and collapse behaviours of the buildings within a certain range of the ground motion intensity. The collapse behaviour of a single building exhibits significant differences with different ground motion intensities. These differences are attributed to the coupling of the nonlinearity of the structures and the randomness of the ground motions. It is concluded that the spatial variability of ground motions should be fully considered in the collapse simulation of buildings.