Floating slabs

[lboada]

What is the difference between a floating and a fixed slab and when is more convenient to use one or the other?

 

[BigH]

Context?

 

[lboada]

The context is to design a building slab inside an industrial building. Water table is only 3ft below grade and soils are mostly composed by clay.

 

[Okiryu]

lboada, look at this:

http://www.eng-tips.com/viewthread.cfm?qid=150917

Also, I would check consolidation settlements of the saturated clay. Settlements may be large assuming that the loaded area is large (large size SOG since it is an industrial building) and if the clay layer is thick. Also, check if you will have new fill to match the proposed grades. New fill loads may be larger than the SOG loads and therefore contribute to more consolidation settlement. The differential settlement of the SOG and the foundation may be critical for deciding betweeen a floating slab vs. a fix slab. I would also consider some capillary break (some engineers also use vapor barriers) under the slab since groundwater is high. Anyway, I know that you will get more comments from the senior guys here in this forum...