New Bank Slab on Grade Built on Top of Old Foundations
New Bank Slab on Grade Built on Top of Old Foundations
(OP)
I have a Bank Project and the Bank CEO does not want to remove the old footings and foundations under the new 5 inch concrte slab. Its 4000 square feet in plan with old brick and concrete footings buried throughout. The site has a nice and clean loamy sand soil for its new foundations. Is uneven or differential settlement the only engineering issue to be concerned about. I believe the new slab will crack due to the buried debris. Any tips will be greatly appreciated.





RE: New Bank Slab on Grade Built on Top of Old Foundations
RE: New Bank Slab on Grade Built on Top of Old Foundations
Everybody that ever remodeled their basement thinks they are an engineer or contractor. You can bet he'll be the first to ask for your E&O Insurance carrier's phone number if the floor settles!
RE: New Bank Slab on Grade Built on Top of Old Foundations
RE: New Bank Slab on Grade Built on Top of Old Foundations
RE: New Bank Slab on Grade Built on Top of Old Foundations
f-d
¡papá gordo ain't no madre flaca!
RE: New Bank Slab on Grade Built on Top of Old Foundations
RE: New Bank Slab on Grade Built on Top of Old Foundations
RE: New Bank Slab on Grade Built on Top of Old Foundations
It is amazing what you can build over if you run a fast roiling surcharge over the site, along with compaction at slab grade. They may need fill on site the site. Or dig a hole, run the surcharge (no need to have it sit a long time) Fill the hole when done.
Then I'd say we gotta do these things:
Design the slab so that any area 10' x10' has nothing under it. That means maybe more than a 5" slab. Maybe some thickened edges.
Then, since not all is that secure, make sure that every wall has joints at least every 10 feet, a joint at each door and above and below each window.
I'd also ask for a release from possible claims later.
Without these modifications, walk away.
RE: New Bank Slab on Grade Built on Top of Old Foundations
RE: New Bank Slab on Grade Built on Top of Old Foundations
1) Reuse the foundations (if you are confident)
2) Make a matt - provides settlment redundancy
3) Provide piles that avoid the debris.
*I would be very weary of any old fill.
Reuse of foundations for urban sites: a best practice handbook (X414)
http://www.ciria.org/acatalog/X414.html
C653 Reuse of Foundations
Tim Chapman Sara Anderson Jan Windle
http:/