SEISMIC SHELVING SYSTEMS
The subject of earthquake-resistant racking is of great importance and enormous complexity, as an earthquake cannot be predicted. With careful and competent planning it is possible to significantly reduce the danger to people and damage to stored material.
The reference standards at European level are the Eurocode 8 series (EN 1998), which refer exclusively to pallet racking.
Steel is a material which, due to its characteristics of elasticity and strength, has proved to be ideal for making anti-seismic racking. Unsafe and poorly positioned racking becomes a real risk, so the following precautions must be taken:
– bracing (cross bracing).
– connecting double rows of shelving units.
– anchoring to the floor using dowels.
– correct positioning.
– storage of goods in cardboard and tied with nylon.
SEISMIC SHELVING SYSTEMS
We are mainly talking about two different designs. For the first one, only static forces (own weight and weight of the goods to be stored) must be taken into account. For the second one, dynamic forces are also taken into account, which act on the rack structure in the event of an earthquake and can reach up to one third of the earth’s acceleration.
DO ALL SHELVES HAVE TO BE EARTHQUAKE RESISTANT?
No! Two main aspects must be considered: the height and the type of shelving. Shelving with shelves are to be considered furniture and therefore up to a height of 3 meters there are no specific rules. The manufacturer has only the obligation to communicate to the customer the seismic zone in which it is located.
DO YOU HAVE TO CERTIFY EVERYTHING THROUGH A THIRD PARTY INSTITUTE OR CERTIFICATION BODY?
No! You only need a self-declaration from the manufacturer with the reference standards.
CAN AN EXISTING SHELVING UNIT BE SECURED TO THE GROUND AND WALLS TO ACHIEVE AN EARTHQUAKE RESISTANT STRUCTURE?
Shelving must be self-supporting and can only be anchored to the floor. It cannot be attached to walls or ceilings.
DOES EARTHQUAKE-RESISTANT DESIGN WORK WITHOUT CROSS BRACING?
Generally, an earthquake-resistant structure needs multiple contentions to ensure stability in case of an earthquake. Only in specific cases and with low seismological load it is possible to build without cross reinforcement, ensuring the stability of the structure. In order to build earthquake-resistant shelving structures it is important to have all the information about the building (floors, ceilings), type of storage of goods and geological evaluation of the building already in the planning phase. Only with all this information the manufacturer is able to design, install and guarantee a structure suitable for the requirement.