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RE: 1997 NDS Equation Error?

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I sent his message with quotes and with a too wide format So here it is
again..

For Seismic Cat. D or E: section 2308.12.8 requires that all sills have
2x2x3/16 washers. With no mention of sill plate size, it applies to all
sills. This is clearly not for sole plates at upper levels. A
clarification that sole plates are exempt would be helpful.

For IBC 2305.3.10, the 2x2x3/16 washers are only required for 2x sill
plates.

Are 2x2x3/16 washers required for sole plates? A sill plate is a  bottom
plate  on the foundation. A  sole , is also a  bottom plate  higher up
in the framing. The last sentence of IBC 2305.3.10 references nailing of
a sill to line 8 of table 2304.9.1. Tabulated line 8 uses the term  sole
. The IBC disregards the difference in meanings of the terms  sill  and
sole . The term  bottom plate  can be used when both  sill  and  sole
apply. Most likely, the table needs the term  sole  changed to  bottom
plate , or else the larger washers applies to all bottom plates of 2x
material.

Sole plate pressure treatments that appear to be of a light green color
are of Hem-Fir. Pressure treated Doug Fir is more of a light chocolate
color with deeper knife cuts. The deeper cuts are needed for the harder
material. This reduces the bolting values by about 9 to 11% and the
nailing by 7%.

The wood to concrete bolting, Mode IIm probably should exclude the side
member moment. See Tech Report 12 page 16. On page 13,  Case A  maybe
more likely than  Case B  for the side member. It may be that the qs
should apply to the full area of the sill plate. I would call it the
Mode IImc. That change would reduce the Mode IIm capacity, in that the
calculated moment applied to the concrete, being checked as the main
member, will increase. The Mode IIm failure of a wood to concrete
connection rotates the bolt a small angle to fail the concrete. That
rotation is less than the rotation required for the wood rotational
resistance Ms.

David Merrick, SE
mrkgp(--nospam--at)pacbell.net.



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