Effect of the seismic excitation angle on the dynamic response of adjacent buildings during pounding

The excitation angle or angle of incidence is the angle in which the horizontal seismic components are applied with respect to the principal structural axes during a time history analysis. In this study, numerical simulations and parametric studies are performed for the investigation of the effect of the angle of seismic incidence on the response of adjacent buildings, which may experience structural pounding during strong earthquakes due to insufficient or no separation distance between them. A specially developed software application has been used that implements a simple and efficient methodology, according to which buildings are modelled in three dimensions and potential impacts are simulated using a novel impact model that takes into account the arbitrary location of impacts and the geometry at the point of impact. Two typical multi-storey buildings and a set of earthquake records have been used in the performed analyses. The results of the conducted parametric studies reveal that it is very important to consider the arbitrary direction of the ground motion with respect to the structural axes of the simulated buildings, especially during pounding, since, in many cases, the detrimental effects of pounding become more pronounced for an excitation angle different from the commonly examined 0 or 90 degrees.