Earthquake-induced pounding between equal height buildings with substantially different dynamic properties

Earthquake-induced structural pounding may result in considerable damage or even collapse of colliding structures during severe ground motions. The aim of the paper is to conduct a detailed investigation on pounding-involved response of two equal height buildings with substantially different dynamic properties, paying a special attention to modelling the non-linear effects taking place during impact as well as observed in the structural behaviour as the result of ground motion excitation. The three-dimensional non-linear response analysis as well as the parametric study have been conducted for earthquake-induced pounding of structures modelled as elastoplastic multi-degree-of-freedom lumped mass systems. The results of the response analysis show that collisions have a significant influence on the behaviour of the lighter and more flexible building causing substantial amplification of the response and leading to considerable permanent deformation due to yielding. On the other hand, it has been found that the behaviour of the heavier and stiffer building is nearly unaffected by collisions between structures. The parametric investigation has led to the conclusion that the peak displacement of the lighter and more flexible building is very sensitive to a change of structural parameters considered (gap size, storey mass, structural stiffness and yield strength), whereas the response of the heavier and stiffer structure can be influenced only negligibly.