×
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

Monolithic Pad Footing Bearing Capacity

Monolithic Pad Footing Bearing Capacity

Monolithic Pad Footing Bearing Capacity

(OP)
I'd like to calculate the maximum capacity of a monolithic pad footing including the sloped sides and any acceptable portion of the slab on grade.

Specs:
4'x4'x16" deep
sloped sides are 45 degrees
4" slab on grade

I typically wouldn't consider using the sloped sides or the slab on grade, but I was curious to know how much a footing such as this can actually support. I normally would only use the 4'x4' area of 16 sq.ft.

I believe that the Hansen method is appropriate for this calculation.?

Thanks

RE: Monolithic Pad Footing Bearing Capacity

(OP)
I neglected to mention soil properties.

c = 0
phi = 32 degrees
weight = 115 psf

Typical soil allowable bearing cpacity = 2500 psf

RE: Monolithic Pad Footing Bearing Capacity

Is this a soil problem or a footing problem?  The soil allowable bearing capacity is usually governed by settlement concerns rather than a shear failure in the soil.  The height of the backfill above the bottom of the footing effects the shear failure stress and thus the slab on grade would contribute to shear resistance.  Normal practice is to use the design soil level as level with the bottom of the footing for conservative calculations.  The strength of the slab in flexure when the footing reacts downward is the limiting case of trying to use the slab as a foundation element.

RE: Monolithic Pad Footing Bearing Capacity

civilperson - I think it is a student problem - but hope I am wrong.

RE: Monolithic Pad Footing Bearing Capacity

I don't think you can reliably count on the contribution of the sloped portion and the slab.  Both would have to be analyzed and reinforced.  This would be difficult to enforce in the field since it is an unusual detail.

RE: Monolithic Pad Footing Bearing Capacity

(OP)
This is a hypothetical problem.

I am curious to know what the soil bearing capacity would be.

I know it isn't common practice to use the sloped sides or the slab...but what if one wanted to?

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