Conventional Foundation design for expansive soil...
Conventional Foundation design for expansive soil...
(OP)
Anyone know where the code specifies foundation design for expansive soil? I've been looking everywhere and all I can seem to find is post-tension design stuff. My client wants a conventional foundation. I'm in California, so CBC 2013 (IBC 2012). Any info would be greatly appreciated. Thanks.






RE: Conventional Foundation design for expansive soil...
It specifies it in Section 1803.5.3
You need a geotech.
RE: Conventional Foundation design for expansive soil...
RE: Conventional Foundation design for expansive soil...
We work on expansive soil commonly.
For high-end residences it varies between.
-Rigid interconnected shallow footings.
-Mat slabs / PT slabs
-Drilled Piers & Gradebeams with voidforms & sonotube sleeves, etc.
There is no "conventional" approach. Depends how nasty the stuff is. If the geotech isn't helping time to get a new geotech...
RE: Conventional Foundation design for expansive soil...
I'd still follow on with the Geotechnical Engineer and get his concurrence. You don't want to be left completely holding the bag on foundation design. Make sure you document your discussion if he won't revise his report.
RE: Conventional Foundation design for expansive soil...
Don't keep paying for dead weight. Sub-consultants are not simply line items to be marked up, they need to be the foundation of your work.
RE: Conventional Foundation design for expansive soil...
"Design of Post Tension slabs on ground" is the publication
To save you some time. It's a lot more concrete using conventional over PT. The whole thing is basically based on rigidity. I did a whole neighborhood on PT waffle slabs. It was not awesome.
If you build in a basement, you get out of the bad soils usually.
Another way to do it is what they do in Texas - cardboard forms running between deep foundations.
RE: Conventional Foundation design for expansive soil...