Page 157 - TCDB combined Book

Chapter 3 DESIGN 133

Building Design:

Concrete Foundations

The method described here should result in fairly accurate concrete work sizing for pricing
purposes on most low-rise standard construction. We recommend that all pre-bid design work be
completed, reviewed and/or designed by an experienced design professional prior to finalizing
your proposal amount. Final design drawings will always require the services of the appropriate
design professional.

Footing, wall and Pier design using a Uniformly Distributed Load method, assumes reasonably
stable soil and no unusual or abnormal sub-grade conditions. Foundation wall width is typically
determined by thickness of the above grade wall being supported with a minimum of 8”. Pier size
is typically determined by the supported column base plate size, and allowance for a reasonable
edge distance and relative location of any integral foundation wall.

UDL = a x l = fa
psf

Where:
a - area supported (span x attributed area in sq. ft.)
l - load total (live + dead in psf)
psf - soil bearing capacity (allowable in psf)
fa - footing area (in sq. ft.)

Reinforcing steel allowance: (based on historical project data)

- 1.0 ft. nominal depth mat footing = 85 lbs./cy -
- 1.33 ft. nominal depth mat footing = 125 lbs./cy
- non-load bearing foundation walls = 115 lbs./cy
- load bearing foundation walls = 155 lbs./cy
- building column piers = 355lbs./cy
- wall footings (non-bearing) = 70 lbs./cy
- wall footings (load bearing) = 170 lbs./cy