ISO 11031 was developed at the request of Japan, which first highlighted the need for a standard to ensure seismic-resistant cranes following the 1995 earthquake in Kobe. The secretariat of the subcommittee that developed the standard is held by DIN, the International Standards Organization member for Germany.
ISO 11031 can be used to calculate seismic loads, and sets out design principles for cranes destined to work in seismically active regions and for cranes required to be seismically resistant.
Klaus Pokorny, secretary of the ISO subcommittee working on design principles and requirements for cranes, said: “To make sure that cranes are safe, we first need to calculate the seismic loads that show how a crane will respond in moderate to severe earthquakes. Then you can use design limit states provided in two forms: serviceability limit and ultimate limit.
“The serviceability limit state (SLS) ensures that the crane can withstand the effects of moderate earthquake ground motions throughout its service lifetime and continue to operate as intended. The ultimate limit state (ULS) requires that the crane structure should not collapse during severe earthquake ground motions, and that the suspended load or any other part of the crane should not fall or harm the public, operators and workers.”
He added: “Any evaluation should take into account the regional seismic conditions as well as the ground surface conditions at the crane location. It’s also important to consider how the crane will be used and any risks that could result from seismic damage.
“Not only will ISO 11031 add a layer of confidence to the industry, it also provides a common technical language so that manufacturers, users and owners understand each other clearly, no matter where they are – a boost for global trade.”