Turndown Slab design

[lutein]

We often use turndown slab, AKA thickened slab footing, for light frame structure with no frost depth requirements.

The slab on grade which pout monolithic with the turndown slab will ended up carrying additional moment resulted from the eccentricity, and I have been using finite element program, like ADAPT to design the footing and slab on grade. This is time consuming.

Therefore, I was wondering if there is any publications that show simplifed version.

Could you please kindly let me know where could i find something about this? I would appreciate it.

 

[rowingengineer]

Lutein,
I kind of confused about your post, if i understand correctly you have a small building, one storey, with light framing?

I would assume this would be designed like a residential building, taking into account the movement of the soil due to moisture effects?

If this is the type of building and the situation we are looking at then I wouldn't know of the correct reference for the USA, however I know the U.S. Army Corps of Engineers have bit of information on foundation on expansive soils, but I would think there is a national code for this. In Australia there is.


When in doubt, just take the next small step.

 

[csd72]

For light wall loads the slab is sufficient to take out the eccentricity.

For higher loads you may want to consider cross beams.

 

[spats]

I attended a ASCE webinar last year on the subject presented by Alexander Newman, P.E. I have a PDF of his slides that presents a simplified procedure, but it's not mine to hand out. I suggest you try to contact him. He listed his phone number as (781) 455-6999.

 

[lutein]

Spats, do you know how I could purchase or get hold of the documents? Could you please inform what seminar was that?
I appreciate that. Thanks.

 

[spats]

I looked again in the PDF... evidently he has written a book, which is the source of the webinar material, "Metal Building Systems: Design and Specifications", 2nd edition (McGraw-Hill 2003). It's available at Amazon.com for $68.80.

http://www.amazon.com/Metal-Building-Systems-Design-Specifications/dp/0071402012