Slab on Grade

[Sharoan M]

Hi,
I have a question regarding slab-on-grade capacity checks. According to ACI 360R – Design of Slabs on Ground (Table 4.2), the factor of safety for concentrated loads (such as rack post loads) is between 1.7 and 2.0. Does this mean I need to apply the factor of 1.7 only to dead loads and product loads, or should I also consider applying this 1.7 factor to seismic loads?

 

[human909]

I don't know your code... But I figure it is is allowable stress rather than limit state. In which case I'd suggest that factor of safety captures a bunch of material factors beyond just variance in load factors. So removing all those material behaviour factor wouldn't seem to make sense.

But then maybe I am completely off the mark...

 

[g.n]

I think that table is for serviceability only, read section 4.9, there should be a sentence referring to ACI 318 for the design of the slab-on-grade if it is used to transmit vertical or lateral loads to other elements. This guide I think is only for slabs transferring the loads to the ground below .