Friday, September 18, 2009

cantilever column system

I have a condition on a project with 11' plate height, with clerestory glass approximately 3' above an 8' tall shear wall, in a light framed 2 story wood framed single family residence.  I intend on using steel columns to transfer roof lateral load to drag at top of shear wall, and would not consider this to be a true cantilver column system.  Prior to the new code, i have been able to justify design as a beam / column drag that transfers loads to drag beam at the top of the shear wall, with the column is designed for an amplified force like an offset on a beam.  I would use the R value for plywood shear wall building rather than cantilever column system.
 
I do not have experience with the new code using this approach.  The new code seems very defined about cantilever systems requiring that they comply with moment frame design requirements. 
 
I am looking for an opinion on whether a beam column model is a reasonable approach for this case.
 
Thanks in advance,
 
Paul Franceschi