Span/Effective Depth Ratio applied to 2 way solid slab 1

[strawhats2000]

Hi all,
I am looking for information regarding span/effective depth ratio for 2 way solid slab. I have a garage with 2 nos. slab panels each 6m x 4m (Area of Garage 6mx8m). I want to know the followng:

1. Should be slab be designed as a continuous slab for support condition hence having a ratio of 26 for basic span/effective ratio or simply supported with a ratio of 20. This is quite important as 6000/(26xmodification factor)=230/mf while 6000/(20mf) = 300/mf for effective depth while normative depth for a slab is between 125 mm to 150 mm here.
2. Uncertainties are due to the following: Here Slab and Beam are cast separately and all slab is basically qualified simply supported. Second, the first panel is connected to the second panel only through the longest side ly while three remaining sides (1 long, 2 short) are discontinued. The same is true for the second panel.
3. What span should be used in the Basic span/effective depth ration. Span along Lx (shortest side) or Span along Ly (longest side).

Regards and Thanks.

 

[txeng91]

If this is all cast in place with beams along the exterior and down the middle, and not precast, you should analyze as a one way slab spanning left to right w/ continuity over middle support. Use ACI minimum thickness without calculating deflections as L/24 (one end continuous) if you can. that would give you about a 170 mm slab. If you want to go thinner you would need to analyze strength and deflection for 40 psf live load or 2500 lb, which I believe are the minimums for passenger vehicles.