Base Isolation System
Base Isolation is a technical system used to reduce the earthquake vulnerability of structures. This technique allows a remarkable reduction of seismic actions, stressing the structures, which hence are able to resist violent earthquakes, thus avoiding cracks or damages to non-structural elements or to goods contained inside.
The base isolators, placed in between the foundations and the superstructure, consist in elements featuring a high horizontal deformability and a high axial stiffness, allowing wide oscillations during a violent earthquake, thus reducing the conveyance of the kinetic energy provided by the earthquake to the superstructure.
The function of the base isolators, in case of earthquake, consists, in fact, in the shift of the fundamental frequency of the fixed-base building in upper range, featuring a low energy content, besides, in some cases, the increase of the damping due to hysteretic mechanisms.
The base isolation system, with the introduction of devices, between the foundations and the base of the structure, represents an appropriate solution, even for the seismic retrofitting of existing structures, suitable, for example, for buildings, featuring a prestigious and historical-artistic value.
The cost effectiveness of earthquake insulation is widely shown in the long-term period: an isolated building, in case of violent earthquake (with a high chance of occurring during its useful life), does not undergo any damage.
Therefore, for many structures, the base isolation system, besides increasing earthquake safety, is cost effective. .