×
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

Equipment Anchorage - Seismic

Equipment Anchorage - Seismic

Equipment Anchorage - Seismic

(OP)
When calculating anchorage forces for mechanical equipment, is the total design lateral seismic force, Fp, the actual numerical value to be used to determine the anchorage forces?

No other inclusion of Fp into load cases needs to be included. Now this is an ultimate load; so using LRFD provisions we could consider this a factored load? What about ASD provisions?

 

RE: Equipment Anchorage - Seismic

The Fp represents the "E" in the required load combinations.  Use this in each combination along with other applicable loads such as Dead Load, Live Load, etc.

It also is an ultimate load so if you are using ASD procedures you would use ASD load combinations which have a 0.7 factor on E to bring it down to unfactored status.

 

RE: Equipment Anchorage - Seismic

(OP)
I am basically just looking at the tension forces from the overturning moment and the horizontal shear forces in the anchorage.

In this case I do not have any additional live loads or dead loads other than the equipment weight. I would also use 0.6D in determing the resisting moment from the self weight of the equipment.

Simliarly if working with the ultimate load Fp the resisting moment would be based on a factored dead load (1.2)

RE: Equipment Anchorage - Seismic

Sounds like you got it.
 

RE: Equipment Anchorage - Seismic

If you are anchoring the equipment to masonry or concrete, look at ASCE 7-05 section 13.4.2. You may need to multiply the seismic force by 1.3. Also, if the anchors are not prequalified for seismic, you may need to reduce Rp to 1.5.

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