×
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!

*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

Structural - Connecting new footing to old footing

Structural - Connecting new footing to old footing

Structural - Connecting new footing to old footing

(OP)
We are looking at installing a new steel gravity column and footing for a G+2 office building very adjacent to an existing G+1 office building. The issue we have is that on of our column footing is coming directly over the edge of the existing footing. We are looking at over pouring the new foundation over the existing. The level difference between the bottom of new and top of old footing is around 350 mm. Can anyone suggest how to sort this issue??

RE: Structural - Connecting new footing to old footing

I would not allow the new to bear on the old.

I would add Styrofoam over the old footing and enlarge the new to the inside if I understan the situation correctly.

Mike McCann, PE, SE (WA)


RE: Structural - Connecting new footing to old footing

Without knowing the allowable bearing capacity of the soil, no way to answer.

RE: Structural - Connecting new footing to old footing

A pic (to give an idea as to where everything is relative to each other would help), however it's usually only after about 2 feet of fill that I consider a load spreading out in the soil. If it is directly over it......and you have to have it......you need to superimpose some load on top of the existing footing. (By the criteria I mentioned.)

RE: Structural - Connecting new footing to old footing

Do not add any load to the existing footing.

Thicken the new footing as required to avoid that.

Mike McCann, PE, SE (WA)


RE: Structural - Connecting new footing to old footing

Quote:

Do not add any load to the existing footing.

Thicken the new footing as required to avoid that.

That sounds like a plan. (Especially if there is no info/different owners for the existing footing.)

RE: Structural - Connecting new footing to old footing

It would certainly help to know the loads (both of the wall and the new column). What is the allowable soil bearing pressure?

Generally, we like to keep the bearing of adjacent footings at the same elevation unless you underpin one footing to keep them at the same elevation. The top of the footing is generally unimportant as long as it is below the bottom of the slab. Another option is to cantilever a beam over a footing to the wall. Anchor the far end of the cantilever to another column footing.

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


Resources

Engineering Report - Top 10 Defect Types in Production
This 22-page report from Instrumental identifies the most common production defect types discovered in 2020, showcases trends from 2019 to 2020, and provides insights on how to prevent potential downtime in 2021. Unlike other methods, Instrumental drives correlations between a variety of data sources to help engineers find and fix root causes. Download Now
White Paper - Addressing Tooling and Casting Requirements at the Design Stage
Several of the tooling and casting requirements of a part can be addressed at the design stage. If these requirements are not addressed at the design stage, lot of time is spent in design iteration when the design reaches the die caster. These design issues lead to increase in time and cost of production leading to delay in time to market and reduced profits for the organization. Download Now

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