1997 UBC Wind Loads for Components
1997 UBC Wind Loads for Components
(OP)
Has anyone ever compared the ASCE 7-02 component wind loads to the 1997 UBC wind loads for components? We started reviewing shop drawings for a project for claddding and girts for a transfer tower using the ASCE spec. and then found out we had to use the UBC. My calcs. show an increase in wind load of 50%. They are saying I am wrong but at this time won't review my calculations. It is costing the fabricator money.
It is exposure C at 105' high, 90 mph, 68 sf. area of cladding for the girt loading.
Thanks
It is exposure C at 105' high, 90 mph, 68 sf. area of cladding for the girt loading.
Thanks
RE: 1997 UBC Wind Loads for Components
UBC 97
Wind - 90 mph
Exp C
Height - 105'
Area 68 sf
qs = 20.8 psf
Wall Elements not in areas of discontinuity - enclosed and unenclosed buildings
Area = 10 sf: +/- 40.6 psf
Area = 100 sf: +/- 30.4 psf
Wall Elements not in areas of discontinuity - partially enclosed buildings
Area = 10 sf: - 54.1 psf
Area = 100 sf: - 43.9 psf
Wall Elements in areas of discontinuity
Area = 10 sf: + 40.6 psf and -50.7 psf
Area = 100 sf: + 30.4 psf and -40.6 psf
RE: 1997 UBC Wind Loads for Components
UBC uses 'fastest mile' wind speed
ASCE uses '3 second gust' wind speed
90mph(3 second gust) converts to approximately a 76mph(fastest mile) wind speed.
or
90mph(fastest mile) converts to approximately a 105mph(3 second gust) wind speed.
RE: 1997 UBC Wind Loads for Components
P=Ce*Cq*qs*Iw
Ce=1.62
Iw=1.15
Qs=20.8
Wall Elements not in areas of discontinuity - enclosed and unenclosed buildings
A=68sf. Cq:1.01
P=39.1 psf- inward & outward
Roof Elements not in areas of discontinuity - enclosed and unenclosed buildings
Cq=1.11
P=43.04 outward
Wall Elements in areas of discontinuity
Cq=1.01 inward
Cq=1.31 outward
p=39.1 psf inward
p= 50.8 psf outward
Roof Elements in areas of discontinuity - enclosed and unenclosed buildings
Cq=1.78
P=69.0 psf outward