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Re: WOOD MOMENT FRAMES

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At 00:03 4/10/98 EDT, RICHARD DAHLMANN, P.E. wrote:

>I HAVE A CLIENT WHO WANTS TO USE A WOOD BEAM IN CONJUNCTION WITH STEEL
COLUMNS
>TO CREATE A MOMENT FRAME. THIS IS RESIDENTIAL CONSTRUCTION IS SEISMIC ZONE 2.
>I AM VERY HESITANT DUE TO:
>1. THE ENORMOUS AMOUNT OF BOLTS REQUIRED AT EACH END
>2. THE IMPRACTICALITY OF EXPECTING RESIDENTIAL CARPENTERS TO GET THE BOLT
>HOLES EXACTLY RIGHT (SINCE THE BOLT HOLE WILL NEED TO BE SNUG WITH THE BOLTS
>IN ORDER TO MAINTAIN A RIGID CONNECTION)
>3. THE POSSIBLE FUTURE ELONGATION OF THE BOLT HOLES DUE TO CONTINUES MOTION
>OVER THE YEARS. 
>
>IF ANYONE HAS ANY SUGGESTIONS, THEY WOULD BE GREATLY APPRECIATED.
>
>RICHARD DAHLMANN, P.E.

Two pieces of advice: 	
1) TURN OFF THE CAPS IN YOUR POSTINGS!!! Its called shouting on the 'Net
and it is very hard to read.

2) Moment joints in wood frame construction are a figment of someone's
imagination. Don't even think about trying to make one work.  The tendency
for bolts to split the wood due to both stress concentrations and
restrained shrinkage, with the resultant loss of ductile behavior, make
these joints very suspect in any seismic design.  Although you may get the
calculations to look like they work, a moment frame joint in wood
construction is truly an oxymoron.
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BILL CAIN, SE
OAKLAND, CA
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