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Hmmm, that's alarming.  I've used these formulas many times and never detected a glitch here. I've gone back and looked at the equation D-5 and I see that you're right.  The An/Ano term gets smaller and approaches unity (1) as the embedment depth increases. This makes sense though, since at very large depths the projected failure surface would look almost the same for one bolt or eight bolts spaced closely together.  I see, however, that the Nb term (basic concrete breakout strength) increases dramatically with effective embedment depth and overides this effect since it is multiplied by the An/Ano ratio. If you still have trouble give me a call.  I could check your specific case on the spreadsheet I'm developing which implements Appendix D.  Also be sure to apply the limits on An properly and limit projected areas affected by the pedestal.
Christopher A. Banbury, PE
Vice President
Nicholson Engineering Associates, Inc.
PO Box 12230, Brooksville, FL 34603
7468 Horse Lake RD, Brooksville, FL 34601
(352) 799-0170 (o)         (352) 754-9167 (f)