BigInch,
A few thoughts on your questions:
Does anyone know exactly why was it changed? What was the objective. Was the objective achieved?
[blue] Since ANSI A58.1, this document that specifies loads for buildings has morphed into ASCE 7 and there have been numerous versions - 98, 02, 05, 10, and now 16. Each time there have been changes to the specified loads (live, snow, wind, seismic, and several others) that appear to be the result of continuing study, research and lessons learned which resulted in more prescriptions of how an engineer can determine what proper loading to apply to their structure. So in a sense, it is a toolbox of sorts with a LOT of information provided.
The concern here in the debate articles I linked to revolves around the theory of how an engineer is either helped or burdened by such voluminous amounts of information. Is it truly information or is it just a lot of burdensome rules to follow that could be replaced by a simpler system.[/blue]
Why do you use the latest version of ASCE 7? Apparently it is not even referenced in a building code yet.
[blue] Wherever a building or structure is located there is most likely an applicable, enforceable building code that will reference out to ASCE 7 and the particular version (i.e. IBC 2012 references ASCE 7-10).
So you shouldn't just automatically use the latest ASCE 7 but rather see which version is reference by the applicable code. ASCE 7-16 will be referenced by IBC 2018 so if and when this code is adopted then 7-16 would be used.[/blue]
Is there some legal requirement to use the hot off the press version, or is it just "practice"?
[blue] The only possible use of a "hot-off-the-press version is that it reflects the latest state-of-the-art knowledge and an engineer can certainly take this into account when designing. The applicable code will enforce MINIMUM standards (i.e. minimum loads) so if the later version suggests that a higher level of load is more accurate, an engineer is free to use their judgement and perhaps use the higher load even though the applicable code technically doesn't require it. But if the newer version of ASCE 7 allows a lower load, then technically you may not want to go below the applicable code provisions.[/blue]
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