Structural Slab
Structural Slab
(OP)
I am designing a structural slab to support a self contained hot-tub. The property has a significant slope and in order to have the tub at the same height as the deck, an "mini foundation" has to be poured. The walls are 9 feet tall and the "foundation" is 15' square. The home owner wants to be able to store garden equip. etc. under the tub in this mini-basement.
Can I design the slab on the top of this 15' square foundation as a one-way slab and just spec. the reinforcement for both directions?
Thanks for your help,
Alex
Can I design the slab on the top of this 15' square foundation as a one-way slab and just spec. the reinforcement for both directions?
Thanks for your help,
Alex






RE: Structural Slab
RE: Structural Slab
RE: Structural Slab
Be careful. Designing a two way slab as one-way with only temperature reinforcement in the transverse direction can lead to significant cracking as the loads redistribute from the initial elastic 2-way distribution. Probably not a safety concern, but a serviceability issue and could have your clients doubting your qualifications.
RE: Structural Slab
Thanks for your help. I normally do log/wood design and am comfortable with standard concrete beams, wall stuff, this was just a little beyond my comfort level. I have several wood engineering programs but nothing with the capability to design (or offer design suggestions) for two way slabs and I like to be able to check my work with a program or another engineer (not an option in this case). The one way slab design is within my comfort level with hand calcs. and software capability. Plus I couldn't find any reference in ACI or my CERM book on how to design a two way slab with the entire bottom part of the slab in tension. It seems like every design method, DDM or Equiv. Frame, involved some sort of interior support. This project is a square slab, supported on all sides...and that's it.
So anyway, I designed it as a one way slab and specified the rebar both directions, but also making sure my rebar ratio, summing both directions, was less than the max. Perhaps overkill...but if anybody thinks this is an unsafe approach I would like to hear your thoughts.
alex
RE: Structural Slab
RE: Structural Slab
RE: Structural Slab
Agree though that the proposed approach of having one-way reo in both directions in conservative and acceptable.
RE: Structural Slab
RE: Structural Slab
RE: Structural Slab