Seismic devices for steel storage structures

The importance of the logistics sector has increased even more in the last year, due to the Pandemic event which lead to an increasing of the online purchases. Goods and products are generally located in steel frames known as steel racks or simply racks. Consequently also the safe design of these structures, i.e. preserve their fully functionality and avoid their collapse, is becoming of paramount importance, especially when they are located in strong and moderate seismic zones. Despite pallet rack provisions for seismic loads have been significantly improved in the recent years, only two classic ways to enhance the seismic performance are considered: rack netting and structural strengthening. Both of these suggested solutions are not fully effective to preserve the integrity of the stored products that, when subjected to strong accelerations, can topple and fall down. The only reliable and effective systems seem to be the introduction of seismic devices, such as base-isolation and energy dissipation systems. Since no indications about these techniques are reported in the standards, many researches worldwide are trying to fill this gap. Unfortunately, up to now, just theoretical studies and very limited applications are available in literature. In the present paper a short overview on the base isolation systems available on the market for different steel storage rack typologies is presented highlighting main advantages and defects of each solution.