Slab on Grade Design Help 2

[Recent Grad Josh]

Hi all,

I'm using ACI 360R-10 to design a slab on grade, but I'm not sure how to account for the load from an interior wall. The load from the wall is something like 3 klf, but assuming the subgrade modulus is k=100 pci, the slab thickness is off the charts. Should I not be using ACI 360R-10 for this part? (A 12" slab works for the distributed loads and vehicle loads)

What is the best way to determine the thickness of a concrete slab on grade from an interior wall load?

I'm very new to the industry, so thanks in advance for any help!

 

[txeng91]

With a load that high, you would probably need to design as a reinforced strip footing. I believe the tables you are looking at don't assume any reinforcement contributing to flexure and are based on rupturing of the concrete on the tension face. I would figure out the bearing capacity and calculate the required width of the footing and see what thickness you need for reasonable reinforcement. You might consider thickening just that portion of the slab to take the load.

If you have a concrete design textbook it should have an example in there. Otherwise this one looks good:

https://www.engineeringexamples.net...ndation-support-single-column-using-aci-code/

A strip footing will be the same design as a spread footing but you just run a 1' section and calculate the thickness and reinforcement for one way shear and flexure, there won't be any 2 way shear or flexure in the long direction.

 

[Recent Grad Josh]

dnlv, thanks so much! That's helpful.

 

[DaveAtkins]

I use "Designing Floor Slabs on Grade" by Ringo and Anderson for this type of problem. According to their chart, a 10" thickened slab, 6'-0" wide, is adequate for 3,094 plf.

DaveAtkins

 

[Ron]

I also use Ringo and Anderson. For some designs, I used elastic layer analysis as well.