Building Driveway/Parking Area (over disturbed soil)

[madmax12]

Thx for all the great input.

 

[mx842]

Thx for all the great input.

Madmax..... First, you probably need to figure out just what your main objective is. Are you waiting for two years just to give the soil a chance to settle on it's own or do you want to pour the pad now and are afraid you can't get proper compaction?

As far as the gravel drive goes... a gravel drive is what it is and will need attention from time to time. Let's do the drive way first. I assume you have been using the drive way for some time and if so you already know where any potential problem spots are. Before you put down any stone make sure you cut out any of these soft spots and back fill them with a larger stone like railroad ballast (3" or 4") and if your quarry has this sized stone with dust mixed in with it use that for small to moderate size areas 1' to 6' in size. If you have a place that is soft or gets rutted for 10' or more you need to cut these spots out a foot or more and fill them in with big clean stone but what you want to do is bridge over these places meaning cut it out and when you start to back fill in these areas don't let the truck driver spread it, back him up to where you want to fill in and stop him a few feet before he gets to the cut out part and have him dump a pile and pull up. Then work the stone into cut area from the center line outwards dumping more stone as needed until the first ten feet or so is good and solid. A crawler type loader or dozer works better than a rubber tire machine with this or a small excavator is even better the main thing is never and I mean never let the truck drive into this area until it is properly built up and bridged over with at least a foot or more of this large stone built up on top of what you have worked into the cut area. The main thing is to work these areas slowly and understand what happens when the heavy loaded trucks wheels do when they drive into a soft area. the area of the tires is small and the weight pushes down forcing the earth on the outside of the wheels to push outward and the earth on the inside of the wheels is forced upward creating a giant water holding crevasse that will never heal up no matter how much stone you dump on it.

Recap, Once the cut area is cut out and leveled stay off of it and bridge the stone over the area never work from the cut area always work into it with a foot or two of large stone under the tracks or wheels of the spreading tractor. Remember a rubber tired spreader is going to make ruts also so you may have to build up the area higher to keep from disturbing the nice level area you are putting the rock on. Work from the center outward and don't get ahead of yourself and let the sub material start to pump up behind you if this starts to happen you are going too fast and don't have enough material under your tracks. It's okay to leave these areas high, a foot or more if needed until everything settles down 6 months or more depending on the weather just level the area off from time to time and as you drive over these areas don't drive in the same track all the time use the whole drive way to help keep it level.

After awhile you will notice that where you had a 2' high pile in the drive way through these areas has now settled down somewhat and then you can top it off with a layer of what ever you are going to put on the rest of the drive way and after a couple years you will never even notice where the soft areas were if done correctly.

What I would do with the area around the barn that you want to pour concrete on is pretty much the same. find any soft areas cut them out fill them with stone. Grade the whole area to get proper drainage away from the building down to at least 11" below the finish grade and put 6" of sub base material, crushed stone or good sandy/clay mix bank gravel then compact it well with a pan type walk behind compactor and put your 5" of concrete down on top of that and forget about it. Well I don't mean forget about it, now you can sit back and enjoy your hard work and don't forget to put up a steel pole someplace where you can attach an old fruit basket for the basket ball games that will most assuredly start to begin happening with all that nice concrete around.:laughing:

 

[madmax12]

mx842, thx for your ideas.

Your reply addresses the OP's project... and mine (I'm not the OP... but I really appreciate all the help).

This picture is a mirror image of what I'm thinking of doing.
http://hillsidestone.org/~hillsidestone/tipe/pictures/gravel_parking_area.jpg

I have an asphalt drive from the street to garage. I'm leaving that alone.
Next to it, is lawn. I want to do what you see in the above picture and put in a gravel drive about that size, in almost the same exact way...abutting the asphalt driveway. But for me, it would be the other side of the house, a mirror image.
Here's a link to a thread of the above picture in stages...scroll down (in the linked page) to see the 5 pics:
http://forums.aaca.org/f196/dirty-gravel-clean-gravel-driveway-parking-258037.html

I was hoping to knock this out before winter... but in Maine, snow could start flying in a few weeks... so, I'm not certain I'll have figured this all out in time. We'll see.

Plenty of other projects to do if I don't get to that one, I guess.:confused2:

 

[mx842]

mx842, thx for your ideas.

Your reply addresses the OP's project... and mine (I'm not the OP... but I really appreciate all the help).

This picture is a mirror image of what I'm thinking of doing.
http://hillsidestone.org/~hillsidestone/tipe/pictures/gravel_parking_area.jpg

I have an asphalt drive from the street to garage. I'm leaving that alone.
Next to it, is lawn. I want to do what you see in the above picture and put in a gravel drive about that size, in almost the same exact way...abutting the asphalt driveway. But for me, it would be the other side of the house, a mirror image.
Here's a link to a thread of the above picture in stages...scroll down (in the linked page) to see the 5 pics:
Dirty Gravel or Clean Gravel for a Driveway/Parking Area?

I was hoping to knock this out before winter... but in Maine, snow could start flying in a few weeks... so, I'm not certain I'll have figured this all out in time. We'll see.

Plenty of other projects to do if I don't get to that one, I guess.:confused2:

I didn't read the whole thread but from what I saw it looks like you are on the right track. The biggest problem with gravel drives other than the regular maintenance is grass growing up through it. I always like to once the sub soil is removed to spray the heck out of the area with a good weed control. Even when you apply some sort of barrier like what was shown in those pics it will still come through. You can apply weed control on it as it comes through as it is part of the maintenance of a gravel drive.

The main idea is to start out on good solid ground that is level with good drainage then big rock down first to stabilize the area then smaller rock on top to seal it off then repair as necessary. Some soils and climates cause more maintenance to be done that's just the nature of a gravel drive or parking area.

 

[madmax12]

thx mx842, schmism, Egon, Ed of all trades, yelbike, MarkV , and boggen :thumbsup:

My first post was intended to provide MMH with links to what I was finding as I learn. But I ended up with a lot of good teachers for my own project.

MMH... how's your project going?

Has the advice here been useful?

 

[GLyford]

When I put in my drive the loader dug out the grass on about 30' of a 100 yard long drive, and I have had more trouble with that 30' than all the rest. I can't see anything that would make that part different except he dug the grass out, about 4" deep. :2cents: next time for me it is gravel on the grass if i can.

I've heard of that happening when the soil doesn't drain well (like certain types of clay) and the dug out section doesn't have any place to drain to.

You're basically making a clay bowl full of gravel where it's been dug out, but if you just put gravel on top and leave the existing grade alone it lets the water keep going without giving it anywhere to collect.

If you have soil like that, that doesn't drain, but have some slope then you can put a ditch on the low side and make sure the dug out section drains out to the ditch, either by having a "cut" from the dug section to the ditch backfilled with gravel, or using a drain or culvert of some kind. I think the key here is the ditch has to be lower than the "floor" of the dug out section to give the water somewhere "downhill" to go away from your driveway.

I don't have that problem at my place...but I'm on sand. It all depends on how your soil reacts to water. Always be thinking "now where's the water going to go next...?"

 

[sdkubota]

I am an engineer and this is my area of expertise. You mentioned the clay is expansive...problem. Also the unpacked fill will be a problem and settle over many, many years. If you had plenty of money you could pre-load the area by building up the soil say 6' higher then your finish grade and allow it to sit for a year to compress the underlying layers. It is extremely difficult and costly to pack soil greater then 2' in depth. If I were you, given the numerous constraints, I would use 8" of gravel and call it good. Even if the fill was packed with the greatest of care...expansive soil is a problem and will cause problems.

 

[yelbike]

I am an engineer and this is my area of expertise. You mentioned the clay is expansive...problem. Also the unpacked fill will be a problem and settle over many, many years. If you had plenty of money you could pre-load the area by building up the soil say 6' higher then your finish grade and allow it to sit for a year to compress the underlying layers. It is extremely difficult and costly to pack soil greater then 2' in depth. If I were you, given the numerous constraints, I would use 8" of gravel and call it good. Even if the fill was packed with the greatest of care...expansive soil is a problem and will cause problems.

Since your an engineer in the field( no pun intended), what's your view on geotextile fabric? Needed or waste of money?

 

[sdkubota]

Since your an engineer in the field( no pun intended), what's your view on geotextile fabric? Needed or waste of money?

There are two main types of geotextiles normally used. The one I believe you are referring to is like a heavy nonwoven felt. Its purpose is to seperate different materials like gravel and subsoil. In certain soils it is very usefull as without it and deep rutting will bring soil into the gravel and contaminating it. It is fairly inexpensive but I still believe in nothing short of 8" of gravel for a good base. The second type is generally referred to as Tensar which was a trade name. It looks somewhat like plastic snow fence with an open grind. The plastic is very strong in tensile strength and the material is placed below the gravel and ends up like a hammock supporting wheel loads above by spreading the tire bearing forces over a very large area. The material is expensive but many roads are built directly over swamp materials that would be impossible without.

Earlier correction: Do I understand your fill depth is relatively shallow (8" - 16") ? Expansive soils still a problem and prone to swell when wet and shrink when dry. Placing an impermeable membrane (concrete) over these soils will cause moisture levels to increase below the slab at different rates than thesurrounding areas...= problem.

 

[sdkubota]

Sorry...didn't really answer your question direct. I would use a geotextile nonwoven fabric if the subsoils were prone to deep rutting when wet. If that wasn't the case I would spend my money on having a good road gravel over the soil and packed well in place.