×
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

Seismic calc's. - Zone vs. Design Category question

Seismic calc's. - Zone vs. Design Category question

Seismic calc's. - Zone vs. Design Category question

(OP)
My company designs and builds patented track underhung bridge cranes & runways, as well as underhung wire rope hoists. Occasionally a customer requires seismic calc's. for an installation. I have done calc's. for Zone 4 applications, but this customer specifies Design Category 3. A zone was not specified. I have found some info on Design Category. How does Design Category differ from Zone, and are there different calc's and acceleration factors used?

Thanks.

RE: Seismic calc's. - Zone vs. Design Category question

What code are you referring to? IBC now uses Design Categories A-F. Zones 1-4 was in the old UBC

RE: Seismic calc's. - Zone vs. Design Category question

(OP)
Sorry, it's IBC.

RE: Seismic calc's. - Zone vs. Design Category question

So do you mean Seismic Design Category C?

Professional and Structural Engineer (ME, NH)
American Concrete Industries
www.americanconcrete.com

RE: Seismic calc's. - Zone vs. Design Category question

They most likely meant risk category, see table 1604.5

RE: Seismic calc's. - Zone vs. Design Category question

(OP)
Seismic Design Category C.

RE: Seismic calc's. - Zone vs. Design Category question

I suggest you get with the program. I don't think zones have been used since UBC '97.

RE: Seismic calc's. - Zone vs. Design Category question

(OP)
I will, gladly. What do I do with the design category?

RE: Seismic calc's. - Zone vs. Design Category question

I may be wrong, but it has always appeared to me that:
SDC A = Zone 1
SDC B = Zone 2
SDC C = Zone 3
SDC D, E, and F = Zone 4, depending on several different factors.

The approximation is rough.

DaveAtkins

RE: Seismic calc's. - Zone vs. Design Category question

Quote (I will, gladly. What do I do with the design category?)


You get a copy of the applicable code, and you read it.

RE: Seismic calc's. - Zone vs. Design Category question

SDC categories give you the rules for implementation, however you need to know the Ss and S1 values to actually be able to determine the seismic factor and thus the loads. Yes there is some correlation between SDC and zone as DaveAtkins mentioned, but it is not a one-to-one such that simply knowing the SDC will give you the seismic factor to use.

RE: Seismic calc's. - Zone vs. Design Category question

(OP)
I've been searching for the code online. ICC.org has available, among many others, a 2015 Code and Commentary, Vol. 2, dealing with structural. Would this be a good buy?

RE: Seismic calc's. - Zone vs. Design Category question

Yes, that would be a good buy.

Most of the seismic information is in the ASCE 7 document though. I would recommend that you buy ASCE 7-10. The seismic loading methodology is quite a bit different than that in the UBC. There is a chapter on seismic loading of non-structural items such as cranes, although I don't think it addresses cranes directly.

RE: Seismic calc's. - Zone vs. Design Category question

(OP)
Thanks for your help.

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