Driveway base over Clay

[shooon]

What's the best way to go about building a good base for a driveway over clay?

I removed all topsoil until I hit solid clay, 24" depth. I've started laying down pit run and compacting with a 3500lb trench packer. It seems like it's not compacting well in a couple spots... seems squishy. Ideally I wanted to throw some shale down over the clay before the pit run, but there are road bans in effect so that is not an option.

I've been putting the pit run down in 2" lifts and compacting each time.. Should I just keep putting more put run down and continue to compact or am I just going to have the same problem until my base layer is more solidified ?

Also this driveway will see some industrial weights.. like fully loaded tractor trailers 50,000 + KGs

 

[pamike]

Wet clay will not pack it will "pump". It just moves around and creates problems.
One method to dry the clay is to rip it open with a disc, rototiller, etc, let it dry, then pack it. Another option is to use hydrated lime or quicklime. Do some google research. I used hydrated lime on my building pad to dry it out...I bought a 2000 lb pallet of bags then dumped the stuff onto the wet areas and worked it in with the skidsteer bucket. The stuff is crazy. It turns a bucket of wet clumpy clay into dry packable fill.

 

[Gear Box]

Our clay in the Midwest we will put 6" of 3" or 4" clear lime rock compact that. Then 3" to 4" of class 5 limestone compacted. They also have rolls of water block material you could use,city street contractors use it quite a bit.

 

[matt_i]

Once you cut the dirt I would have personally put down geotex fabric and then everything else on top of it.

If places are sinking the only fix is to carve out and go to larger and larger stone-size until you find one that can't squish into the grade below.

 

[jhelrey]

Did you put anything between the clay and the rock?

 

[Bondo]

Once you cut the dirt I would have personally put down geotex fabric and then everything else on top of it.

Ayuh,.... That's how We do it,....

With geotextile over the clay, you'll be buildin' a 2' thick bridge of stone over the nasty ****,....
It also helps to fill the 1st foot, 'n 1/2 with large rock, then topped with 3/4" minus,....