×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • 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!
  • Students Click Here

*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.

Students Click Here

Jobs

IBC 2003 - Table 1604.3

IBC 2003 - Table 1604.3

IBC 2003 - Table 1604.3

(OP)
In IBC 2003 - Table 1604.3, note f states "The wind load is permitted to be taken as .7 times the "component and cladding" loads for the purpose of determining deflection limits herein."

Anyone know the origin of this note? Is it similar to the serviceability for drift information in ASCE?

Thanks.
 

RC
All that is necessary for the triumph of evil is that good men do nothing.
    Edmund Burke

 

RE: IBC 2003 - Table 1604.3

(OP)
Thanks for the information, but the note in IBC only states for components and cladding, where that thread was discussing drift limits of MWFRS.

Any ideas on why this is limited to C+C?

RC
All that is necessary for the triumph of evil is that good men do nothing.
    Edmund Burke

 

RE: IBC 2003 - Table 1604.3

Could it be that the reason for the 0.7 (per the linked threads) is that it is based on the statistical differences of the wind pressures that only really affect the peak pressures that C&C are so susceptible to?...while the MWFRS wind is more of a global averaging of the wind over larger areas and thus not affected to any degree by the difference in the statistical wind measurements?

 

RE: IBC 2003 - Table 1604.3

I used 0.7W for checking serviceability drifts of MWRS all the time - the code does not explicitly cover wind drifts and thus it is left up to engineering judgement.  

RE: IBC 2003 - Table 1604.3

There is a return period factor in the commentary of ASCE 7. Typically as WillisV pointed out, drifts are checked for a 10 year return period storm while strength design is done at a 50 year return period. The factor for a 10 year return period is around 0.7.

RE: IBC 2003 - Table 1604.3

I agree with Willis.  We use 0.7W for checking drifts all the time.  I don't think this in inappropriate.  First, it accounts for the 10-year return period (though, admittedly, I do use 0.71 for V=90mps, and a different - slightly higher - factor for higher velocities); Second, if you want to get technical, the MWFRS and C&C wind loads are the same if the trib area is >750ft2, as would be the case for the whole building when checking drift.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

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!


Resources