Portal frame with hold-downs in engineered building?

[AaronMcD]

I was just perusing the California Building Code and discovered the existence of portal frames with hold-downs. I guess they can be use in typical non-engineered light frame construction, but I can't find any use of them in engineered construction (except for some random calc package I found through google). Would they be permitted? Would they behave? If so, what would be the appropriate response modification coefficient?

 

[bhiggins]

The APA portal frame is a tested and rated assembly that should be permitted for seismic design. Here's a report from the APA:

http://www.anthonyforest.com/assets/pdf/apa/glulam/Tech_Topics_A_Portal_Frame.pdf

From the report: "For seismic design, APA recommends using the design coefficients and factors for light-frame (wood) walls sheathed with wood structural panels rated for shear resistance (Item 15 of Table 12.2-1 of ASCE 7-10). See APA Report T2004-59 for more details."

 

[AaronMcD]

Thanks! I saw that report, but somehow missed the seismic coefficients (yeah I obviously didn't fully read it before posting here). The system isn't mentioned in ASCE 7, and the APA report isn't referenced by the code as far as I know so I still wonder if it would be permitted in high seismic areas. Any idea what the "load factor" column in the table is for? Or am I missing somewhere it explains this?