Consequences of mechanical properties variability of seismic isolation systems on the structural response of buildings

Structural vulnerability of buildings can be significantly reduced if seismic isolation systems are implemented at the base of the overall system. Thanks to the low stiffness characteristics, reduced forces are experienced during a seismic event, whereas displacements are limited by the provided energy dissipation of the installed devices. In the design phase, for the assessment of the response of a considered structure, deterministic mechanical parameters are generally assumed, which correspond to the mean values of the real experimental response. On the other hand, outcomes of several testing campaigns have revealed non negligible variability of the main response characteristics of isolators, which may lead to unexpected behaviors of the isolated structure. In the present endeavor a parametric study has been performed, in order to evaluate the consequences of the variability of the main mechanical characteristics of the implemented devices on the response of a base-isolated structure. Concave Surface Slider devices have been considered: results have led to preliminary guidelines for the correct assumptions in the design phase of isolation devices in real applications.