JStephen - what you describe is what AASHTO considers fatigue, so we are talking about the same thing. There's four types of fatigue to design for: galloping (what you described), natural wind gusts, truck gusts and vortex shedding. For high mast lighting only vortex shedding and natural wind...
There's .pdf files of NCHRP 469, probably can be found at trb.org There's two files - one is examples. (I think it's free - at least it used to be)
I think most manufacturers have design tables, including foundation forces; I can remember only having to design foundations and letting...
I don't know the answer, but did you check applicable ASTM for clues?
HgTX - One possible reason it may be ok for nuts but not bolt heads (and again I don't know that it is) is they may have different chemical composition.
The Missouri DOT has some info in their rating manual found here on page 7 - http://modot.org/pdf/business/bridgesection_4.pdf
It's just a statistical analysis using standard deviations. The more samples you get the less uncertainty you apply to your "average" value.
I was in the same boat as...
For the bridges with drilled shafts I've designed, I've always used L-pile (p-y curves) to locate fixity. I've found that unless the unsupported length of the shaft is very long, that it just doesn't take much embedment to achieve fixity. I seem to recall the 1D rule of thumb, too, but I think...
