Once20036, I agree with you with the interior condition would not be conducive to moisture, frost protection on exterior. However, I interpret that both ACI and IBC are pretty clear that if the slab transmits loads from "other parts of the structure" to the soil it must be designed as a footing...
ACI states: 1.1.7 — This Code does not govern design and construction of slabs-on-ground, unless the slab transmits vertical loads or lateral forces from other portions of the structure to the soil.
Since your slab does transmit loads from other portion of the structure (columns) to the soils, I...
Looking at AISC 360-10, Appendix 6, 6.3 Beam Bracing (Relative Bracing).
We have equations A-6-5: Prb = 0.008*Mr*Cd/h0
And equation A-6-6: βbr = (1/Φ)*(4*Mr*Cd/Lb*h0).
h0 is defined as the distance between the flange centroids. But what if the beam you are bracing is not a W, S, or HP...
ACI 318-11, section 22.7.4 says plains concrete footings shall not be less than 8".
But, since this particular footing is reinforced, I wouldn't' think it applies.
Minimum thickness of the footing will likely be dictated by several issues:
- ACI 318-11, Section 15.7 requires a minimum depth above the bott reinforcement no less than 6". with cover of 3 inches below and reif. diameter, you are looking at a min of 10"
-Look into section 1809 of IBC 2012...
I'm not too familiar with Eurocode, and I do not have a readily available copy with me.
I really wish we had some references for Chapter 22, but none are listed.
mike20793, you are correct. there is a separate equation for 2 way action. The case I'm looking is strictly one-way action.
Also, the 2-way action includes the 4/3 term... so I assume it also takes into account a similar stress.
Thanks for the feedback, Kootk.
DaveAtkins, normally I would agree with you however the commentary to that section specifically mentions STRESS and references the STRESS equation c=VQ/Ib. so, in this case, we are warranted in discussing stress.
On ACI 318-11, chapter 22, section 22.5.4 we have the equation for beam-action shear as: Vn = (4/3)*λ*(sqrt(f'c))*b*h.
Chapter 22 has no references at all, but the commentary indicated the expression is derived from v=VQ/Ib (Mech of Materials equation for shear stress). I suspect the 4/3 part...
