Effect of the seismic excitation's incidence angle on the nonlinear behavior of base isolated buildings considering pounding to adjacent moat walls

In the last decades, a number of reconnaissance reports have revealed that pounding between adjacent buildings, during strong earthquakes, may induce local and in some extreme cases severe structural damage. The problem of earthquake-induced pounding of adjacent buildings has been the subject of great scientific interest, while several recent numerical studies have quantified the effects of seismic pounding of buildings, with the majority of researchers simulating the problem in two dimensions (2D). The results from the various 2D parametric studies have demonstrated the potentially detrimental effects of pounding on the dynamic response of multistory buildings and revealed the importance of this problem regarding the safety and functionality of colliding structures. Furthermore, most of the numerical studies have been limited to the utilization of linear elastic structural models to simulate the adjacent buildings. The current study parametrically investigates the effect of pounding on the inelastic response of base isolated structures, which are simulated as non-linear 3D multi-degree of freedom systems subjected to bidirectional earthquake excitations. Specifically, the influence of certain parameters, such as the angle of the seismic incidence, the width of the seismic gap, characteristics of the isolation system and the configuration of the adjacent structures on the peak response, is parametrically examined, for various near-fault excitations. All numerical simulations are performed using a specially developed software that implements an innovative, simple and efficient approach to model impacts in 3D, taking into account the arbitrary location of contact points and the geometry at the vicinity of impact.