×
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

foundation with two way eccentricity

foundation with two way eccentricity

foundation with two way eccentricity

(OP)
I have a column with uplift and horizontal reactions in two directions at the base.  I would like to size the footing to resist the uplift and keep the dimensions as small as possible.  I have a copy of Principles of Foundation Engineering by Braja M. Das that I am using to calculate the effective bearing area and soil bearing pressures.  My question is, besides the bearing capacity of the soil, what else should I be concerned with in sizing the footing?  At what point does this become unstable?  Do you think that the footing is acceptable as long as I maintain an adequate factor of safety against overturning on the individual footing?  Say (OTM)/((FTG WT) x FTG LENGTH/2)) > 1.5

RE: foundation with two way eccentricity

Also maintain an adequate factor of safety against sliding.

DaveAtkins

RE: foundation with two way eccentricity

Keep your resultant within the Kern distance.

RE: foundation with two way eccentricity

Not necessary to keep within the kern - as long as the bearing pressure under the reduced bearing area is acceptable.

RE: foundation with two way eccentricity

I usually look at eccentrically loaded footings similar to a retaining wall foundation which that book you have cover very well. You have max bearing pressure at the "front" to check(two dirs in this case). Uplift on the "back". Overturning. I doubt sliding will be an issue if you dont have lateral force. Besides that, the footing itself needs to be designed. For this, you probably should look at a concrete book.

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