Seismic allowable loads increase?

[Robert222]

What is the permitted allowable stress increase when using wind and seismic load combination per IBC2006 ?

I lived in belief that it shall be 133%.
But some manufacturers like simpson, usp etc. have 133% or 160%.

Where is the truth?

thanks.

 

[JAE]

Under the IBC 2006, a 1/3 stress increase isn't allowed anymore - see section 1605.3.1.1 (except for DLF for wood).

 

[ajh1]

ASCE 7-05 Section 12.4.3.3 does permit a stress increase of 1.2 for overstrength factor conditions when designing per ASD. But that is the only stress increase mentioned within the code.

 

[Robert222]

160% at strongtie.com catalog is not allowed per code?

 

[WillisV]

The 160% increase in Simpson's catalog is a material specific load duration increase of 1.6 for ASD design of wood subjected to wind or seismic loading. This does not apply to other materials. See the NDS for more information on load duration factors for wood design.

 

[Robert222]

Does it mean that i can use 160% per simpson + 1.2 increase per ASCE ? both together?