INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Member Login

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips now!

Talk With Other Members
Be Notified Of Responses
To Your Posts
Keyword Search
One-Click Access To Your
Favorite Forums
Automated Signatures
On Your Posts
Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Indeed Jobs

LINK TO THIS FORUM!

Eng-Tips LinkedIn^® Group

Join our
LinkedIn^® Group!

Hook up with past and present colleagues and classmates quickly.

Partner With Us!

"Best Of Breed" Forums Add Stickiness To Your Site

(Download This Button Today!)

Feedback

"...love the site and am constantly recommending it to (selected !) clients here in ireland..."

More...

Geography

Where in the world do Eng-Tips members come from?

Click Here To Find Out!

Eng-Tips Shirts!

Get your
Eng-Tips Forums
SWAG here!

Home > Forums > Structural Engineers > Activities > Structural engineering other technical topics Forum

1997 UBC Wind Loads for Components

Read More Threads Like This One

Berniedog (Structural)

16 Oct 08 11:20

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

JAE (Structural)

16 Oct 08 15:47

Here's what I get:

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

WAMRE (Structural)

16 Oct 08 19:40

Make sure you are using the correct/converted wind speeds between the two methods... then I believe they should be fairly close for the resultant pressures (not 50% difference).

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.

Berniedog (Structural)

17 Oct 08 8:57

JAE WAMRE Thanks. Can you take a look at the following:

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

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!

Back To Forum

Back To Structural engineering other technical topics