×
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 Response factor (R) for supporting structure of a horizontal vessel

Seismic Response factor (R) for supporting structure of a horizontal vessel

Seismic Response factor (R) for supporting structure of a horizontal vessel

(OP)
The guy who review our engineering, told me that we have to use a response factor R = 2, for the structure in the subject in this forum. I think this is very conservative, because the vessel is supported by steel structure at ground level upon a slab that supports the whole thing (equipment and structure). He is taking into acount the table 4.C.1, point 2.0 of the "ASCE Guidelines for Seismic Evaluation and Design of Petrochemical Facilities". There is clearly shown that if T < 0.06 s, you can use R = 3; other way, you have to use R = 2. In staad I model the vessel to obtain T (with the Rayleigh tool), but of course, software gave me what I do not want, that is T > 0.06.

The question is easy: Can I demonstrate him that is rigid to use R = 3? How can I do that?

RE: Seismic Response factor (R) for supporting structure of a horizontal vessel

The vessel itself probably is rigid, but the support stl which you have not described may not be rigid....

RE: Seismic Response factor (R) for supporting structure of a horizontal vessel

I'm looking at Table 15.4.2 of ASCE7-10 and I'd say this sounds like it is probably a "Horizontal, saddle supported welded steel vessel" with R = 3.

If you consider it to be an "elevated tank on unbraced legs or asymmetrically braced legs" then it could be R=2

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