Contact US

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!

*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

Moment frame foundation design

Moment frame foundation design

Moment frame foundation design

When designing a moment frame what is the procedure for doing the foundation? I’ve seen people do a “rolling” (idk how to describe it) calc where they have a triangular pressure for the soil bearing. Do you know what I’m referring to? Is this the right way? Thoughts? Can someone point me in the direction of a good resource regarding moment frame design/calcs? Thanks.

RE: Moment frame foundation design

Depends on how you're restraining the moment frame. Fixed base or pin? Single footing or one for each column?

Individual footings are straightforward - so I'm assuming that's not what you have.

Single footing is a bit more complicated. I know what you mean by the 'rolling' foundation - where you just put the moment from the moment frame on the footing and call it good. For very small moment frames resisting wind in a single story house, sure...it might work well enough...but anything larger/more consequential I wouldn't do it that way. For that to work, the stiffness of the foundation would have to be pretty incredible. So for a really short moment frame, it can be plausible. But you'd need to look at flexure in the concrete as well as uplift loading and down-loading from gravity loads and the frame action resisting the lateral loads. Look into beams on elastic foundations - there are some relatively simple numerical approximations you can use.

If you have a single footing with pinned bases, you'll just have shear and vertical loading. For that I might try superposition with a more traditional footing analysis. Look at the loading from each column separately and apply them to the foundation. Then superimpose them to see what the actual bending moment and shear diagrams look like for the footing, as well as bearing pressures.

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! Already a Member? Login


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