ASCE 7-10 Service Wind
ASCE 7-10 Service Wind
(OP)
IBC 2012 Table 1604.3 Footnote f permits 0.42 times the components and cladding wind pressure for checking deflection. I know this is relating the ultimate pressure to a 10-year service pressure and the derivation of this pressure includes the occupancy category based wind speed.
However, when checking drift (or service wind in general) by ASCE 7-10 Commentary Appendix C, the equation is D + 0.5L + Wa where Wa is taken from Figures CC-1 (for 10 year wind service wind for example), CC-2, CC-3. This comes directly from the maps no matter the category of building.
ASCE 7-05 Appendix C used D + 0.5L + 0.7W where W was developed based on the old importance factors.
So it appears that IBC 2012 "permits" us to check C&C service deflections using the a factor on the wind developed based on the occupancy category. And ASCE 7-10 Appendix C does not account for the building category for its service wind which should apply to either drift or C&C deformation checks. And this is a change from ASCE 7-05 and is not coinciding with what IBC 2012 is "permitting".
Thoughts?
However, when checking drift (or service wind in general) by ASCE 7-10 Commentary Appendix C, the equation is D + 0.5L + Wa where Wa is taken from Figures CC-1 (for 10 year wind service wind for example), CC-2, CC-3. This comes directly from the maps no matter the category of building.
ASCE 7-05 Appendix C used D + 0.5L + 0.7W where W was developed based on the old importance factors.
So it appears that IBC 2012 "permits" us to check C&C service deflections using the a factor on the wind developed based on the occupancy category. And ASCE 7-10 Appendix C does not account for the building category for its service wind which should apply to either drift or C&C deformation checks. And this is a change from ASCE 7-05 and is not coinciding with what IBC 2012 is "permitting".
Thoughts?






RE: ASCE 7-10 Service Wind