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Fwd:Re:Fwd:Foundation A.B. Capacity

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Please check out ICBO ES web page for NER 469


No HD15 in our reports only up to HD10A.

D8A and HD10A Automated Holdown Anchors: The HD8A and HD10A automated holdown
anchors connect vertical wood members to foundations. The self-anchors provide a
seven-bolt diameter spacing for the bolt closest to the end of the connected
wood member. A 3/8-inch load-transfer plate is the seat element on which the
wood post bears. The anchors are die-formed from No. 7 gauge galvanized steel.
See Table No. VI for allowable loads and fasteners schedule.

Original message:

I am trying to find the capacity of an anchor bolt in a residential
foundation wall.  The case has a large uplift do to a "Simpson" holdown
(about 15k service loading). It is a traditional 8" foundation wall with
a simpson HD15 anchor that requires a 1.25" dia anchor bolt.  Simpson
doesn't make a corresponding SSTB.  I tried to design an anchor bolt
using the provisions of ch19, div III but am very confused.  According
to the provisions, I first calculate the projected area area at the top
of the wall (Ap) then reduce according to edge distance.  The reduction
amounts to edge distance divided by embedment length.  I have two close
edges (4") so I squared the reduction.  After doing all this, the UBC is
trying to tell me that a 30" long A.B. is weaker than a 12" long A.B. 
If someone could clarify these provisions, I would be very grateful.

P.S. Here's the fun part, if I design it at as a rebar, then I have more
than 10x the capacity of an A.B.


Thanks in advance, 
        Jake Watson, E.I.T
        Salt Lake City, UT