Yes codes are an interesting animal, esp. in the US. Most countries only have one (building code), although even here in Canada there are a few provincial variations on the National Bldg. Code. In the US, there is the UBC/IBC, BOCA, SBC, and numerous state and municipal variations.
I can't say I recognise the term "performance based design", but in general the US codes are moving toward Limit State Design approach (also called LRFD) in which various "limits" of failure are defined (strength, buckling, fatigue, service). Every structure then has to have all it's parts stay inside all of those predefined envelopes.
What becomes difficult with any code, is the assignment of factors and combinations. Also with seismic analysis, there are many ways to analyse a structure: modal, spectral, etc. I would like to see more of the "guts" from a performance based approach to compare and contrast.
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Member of the SSPIA Senior Committee. Have a question? Go pester Tony.
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