Smart questions
Smart answers
Smart people
Join Eng-Tips Forums

Member Login

Remember Me
Forgot Password?
Join Us!

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!

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

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.
Jobs from Indeed

Link To This Forum!

Partner Button
Add Stickiness To Your Site By Linking To This Professionally Managed Technical Forum.
Just copy and paste the
code below into your site.

Berniedog (Structural) (OP)
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.

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.
90mph(fastest mile) converts to approximately a 105mph(3 second gust) wind speed.  
Berniedog (Structural) (OP)
17 Oct 08 8:57
JAE WAMRE Thanks.  Can you take a look at the following:

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
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

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

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close