Design of Heavy Loaded SOG

[dengebre]

We have been asked to design a large shipping container warehouse where the floor live load is 2,500 psf (specified by the user client). The SOG will be supported on soil that will be improved by stone columns (subgrade modulus = 100 pci after improvement). That design load is off the charts of every design resource we have. Does anyone have a sense of what slab thickness we should expect?

 

[KootK]

The stone column business makes me a bit nervous. I realise that the associated improvement is usually thought to spread throughout the soil mass but, at the same time, I'd have to think that the columns would represent local stiffness concentrations. And that, unfortunately, starts to make your SOG feel a bit like a column supported suspended slab. Have you had a chance to discuss this particular aspect with your geotechnical engineer?

 

[dik]

Geotekkie invaluable for this... also, long term settlement. The load is extremely high. What happens in areas that are unloaded? Potential for really high moments. Is the client sure of his loads?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[KootK]

A system that appeals to me mechanically would be a network of grade beams running between the stone columns and then a relatively thin suspended slab spanning between those. Although, at that point, perhaps conventional piling would start to make more sense.

 

[dik]

With that sort of live loading, I'm not sure a piled foundation will be of much help... horrendously expensive.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[HTURKAK]

Does anyone have a sense of what slab thickness we should expect[/b]?]

Yes ...i have a sense .. if you perform FEM analysis for SOG assuming Winkler model, you may find 16 in. or more thk. The problem, 2,500 psf specified loading is not so uniform for the whole SOG. The specified load would be valid at foot prints of container stacks.

I got similar problem for some decades ago.. In my case , the loading was for steel plate / slab stacks and the loading was more than 2,500 psf.
I have decided to delete the SOG and i just used compacted gravel for the surface and the steel slabs stacked on timber sleepers 8in X 8 in. at every 5 ft.
I just wanted to share a past experience..
Good luck..

 

[dik]

Great solution... used that for stacking containers 3 high... temporary condition only...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[WARose]

I think this screams for a pile foundation with a mat on top. With that kind of load.....and with the load location so variable......you'd get differential settlement issues over time otherwise.