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slab on grade or not?

slab on grade or not?

slab on grade or not?

I am in the process of designing a slab and footings for basically a raised equipment pad for a 90,000 lb generator (about 700 lb/sq ft). It is a 21' by 60' pad supported on all four sides raised about 6' above grade.  There will be compacted "structural fill" on the inside of the footings underneath the slab.  The slab will sit on the footings and fill material.  How would I go about finding a thickness for the slab?  a one way slab design? slab on grade? where can i find info about slabs on grade?


RE: slab on grade or not?

Normal equipment loadings are treated as foot print point live loadings, not building uniform loading.  The structural adequacy must be insured.  ANSI A58, ACI Design Handbook or CRSI Handbook can be used as a guide.

Utilize a spread footing for the equipment loading, estimate the footing size and the factored net soil pressure, check the thickness for two way shear, one way shear, size the reinforcement for the ultimate moment, check the developement and design the remaining slab.

Watch out for soil setting.


RE: slab on grade or not?

See my note for your question in the Structural Forum regarding dynamic loading.

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