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Posted: Sun Mar 27, 2005 12:05 pm
by saratoga
We have a long curved driveway (currently a rutted track) over completely clay soil. The curve is the low point of the drive and the whole property in general. When it rains the curve turns into a boggy, sticky clay mess that has so far sucked up trailer loads of gravel that we have poured into it to try to stabilise it (there is an intact round cement culvert that runs under it that septic pipes and drainage pipes have been run through.) We know we need to make a permanent drive and improve drainage on the drive itself, but my question is, what kind of sub-base should we use, and should we use a geotextile to keep the sub-base from sinking into the clay? What kind of drainage is best on the sides of the drive? (The drive will likely be gravel.) Any help would be appreciated, as the house is in France and communication is difficult there.

Posted: Tue Mar 29, 2005 2:22 pm
by danensis
Depends how deep the bed of clay is. Limestone chippings are a good bet, as they will counteract the acidity of the clay.

Posted: Mon Apr 04, 2005 12:06 am
by Tony McC
You really need onsite advice. I'd suspect that a geo-textile will be essential, and that some form of sub-base will be needed to support the eventual surfacing, but without knowing the site, it's impossible to say what would be best - it might need 600mm of capping and improvement layers, or it might just need 200mm of good quality crushed stone and a geo-textile.

Posted: Fri Jun 03, 2005 8:13 pm
by moot de noo
Saratoga, do as Tony suggests and get some advice. If you put in some sort of capping over geo-textile and then subbase to level and build on that it should work. unfortunately, depending on how the ground water moves, what you could then have is a big drainage issue, i.e the water can't get away from the granular material which will eventually destroy itself!

I would suggest a porous subbase over textile (something like SHW Type2 combined with some form of fin drainage to a culvert or similar which will allow water movements through the pavement.

Hope this helps :;):