Utformning av byggnader för säkerhet mot fortskridande ras.

Sammanfattning: A progressive collapse implies a structural failure initiated by a local damage which subsequently develops, as a chain reaction, into a failure of either the entire structural system, or only a part of it. The collapse of the Ronan Point building in London 1968 prompted numerous efforts to develop structural design criteria to prevent progressive collapse. Improved design procedures with the intention to control the likelihood of progressive collapse are now again receiving heightened interest by engineers in the aftermath of the terrorist attack against World Trade Center September 11, 2001. There are two different design conditions in Sweden with the aim of preventing progressive collapse. ”Condition a” is a direct design stipulation, whereas ”condition b” is an indirect design requirement. The Swedish building designs usually meet ”condition b” in order to prevent progressive collapse. This master thesis covers the design criteria which have been established to prevent progressive collapse and at the end of the work examples of how to proceed with indirect design and direct design respectively are shown. If both the indirect and direct design theory is used when designing buildings, the risk for progressive collapse should be minimal.