I've got an interesting dirt-filled hole safety problem

[ragkar]

I've been digging up these stumps for the past couple weeks and leaving holes, some of them four feet deep and five across. The backyard looks like craters of the moon and it's becoming a chore to weave around them. So I start refilling starting with a shallow one foot hole about five feet across. Now I discover that dirt doesn't pack well. About all I can do, without putting a wheel in the dirt fill, is dump dirt on top and press it down with my loader. I moved a bit forwards and a wheel started to sink!
I'd hate to think what would happen if it was one of the four foot deep holes.
I like holes. They're great places to bury the many, many rocks and boulders that protrude from the ground. I want to get rid of them so that I don't have to buy a foot of dirt fill when it comes time to build a lawn.
My solution, tell me what you think of it, is to bury boulders and rocks in those hole till they're about a foot or so from the surface. Then add dirt.

 

[BarryinMN]

The freeze thaw cycle will bring rocks back to the surface again.

The hole fill will firm up faster with compressing every 6" or so vs 4' at once. Water also helps. A freeze thaw cycle or 2 is best.

 

[California]

Do a little Google research on roadbuilding. In rough outline: dirt is laid down in 6 inch 'lifts'. Then water sprayed on. Then the layer is compressed with a sheepsfoot roller. (Its impossible to compress a thicker layer).

Then another layer etc. This gives compaction as good as native earth. (which is what you need to avoid future settling.) I don't think you can get stuck in a 6 inch layer.

When I remove orchard stumps I roll the fill with a front tire and occasionally have to put the loader on the ground as a toboggan to back out (2 wd) if the tire sunk badly. After it is partly compressed, roll it again with the rear tire. I've never gotten stuck. Dunno about rocks floating out - no frost here. But I'm sure you need excellent compaction around any solid object you throw in there.

 

[ragkar]

"I roll the fill with a front tire and occasionally have to put the loader on the ground as a toboggan to back out (2 wd) if the tire sunk badly."
I never thought of that. I'll have to remember that trick.

 

[Grrrr]

I would just put the soil in a bit at a time and then drive all over it. Then put some more in and drive over that.

 

[Egon]

Cut down the edges of the hole and put the dirt in the hole. That will make it easier to backfill with dirt.

You may be able to fill with some stone as long as its on the bottom and well covered. If you do it might be wise to make a plan so you know where they are in the future.

 

[EddieWalker]

I'm with Grrr. Keep is simple.

Fill with dirt, then drive over it with your front tire. Of course, the dirt will settle, but you have a loader, so you won't go down so far that you will get stuck.

Drive over the hole over and over again. Then add more dirt and do it all over again. In no time, the hole will fill up and become solid enough to drive on and pretty soon you won't remember where it was.

If you are planning on building over the holes, the procedure is more involved, but for a field, or lawn, it's not too complicated. Your tires will do a great job of packing it down.

Eddie

 

[ragkar]

Drive over the hole!!! Is that safe?
Suppose my left wheel is on original dirt surface and the right wheel sinks to the axle - 15 inches I measured it. Will that cause a tip over?
I sure hope that I remembered to lower the loader so it's no more than four or five inches high.
I think that filling the hole with rocks and boulders to within a foot will minimize any wheel sinking. But I'm thinking that I could expect ground sinking in the coming months as the top dirt sifts down to fill the crannies between rocks.
Fortunately my deep hole problem will go away as I dig up the last of the stumps. Even the biggest boulders shouldn't leave more than two foot deep holes - I hope.

 

[EddieWalker]

Putting rocks and other large items back in the hole will fill it up faster, but it will also lead to other issues. The trick to making any fill solid is to be able to compact it. As mentioned earlier, the best way to do this is to lay out the material in thin layers. Compact that layer and then do it again. The thickness of the layer depends on your compaction ability and soil type. Don't assume that a certain thickness in one area will work in all areas with all soils. When I'm building a pad for a building, I use my FEL and put it down one yard at a time, then back drag it with the bucket to get an inch of lift at a time.

The biggest problem you will have with putting large items in the holes is the inability to compact it. You can get close if you really work at it, but you will never get it solid. There will always be soft spots or even air pockets around the large material. Rain water will find these spots and over a very short period of time, will erode your hole from the inside. This is also called a sinkhole.

Every place you do this will develop potholes, or low spots. Depending on how bad it is, this might take a little or almost a never ending cycle to fill and smooth them out.

Fill the hole with clean dirt and compact it with your front tires. Even better, load your FEL with a load of dirt for more weight. Your tractor will not flip with one tire in a hole. Just for fun, try it. Just drive to the edge of your hole with nothing else in it. Put the FEL fairly close to the ground and drive into the hole. You can lift and lower your tractor with the FEL to easily get out if you are stuck.

Usually when I do this, I'm not planning on it and it's a suprise. I have 2wd on my tractor and it's just a simple matter of lifting the tire back out of the hole with the FEL and backing out. Piece of cake!!!

With dirt in the hole, it's not gonna be as severe. The whole idea is to sink the tires into the hole. The deeper the better. Then put more dirt into the hole and do it again. When you stop sinking your hole is full!!! Add a little more to create a small crown to keep water from sitting on the fresh dirt.

Eddie

 

[TedLaRue]

In addition to the good suggestions above, don't forget that you can split your brakes and skid-steer your way out if one wheel is in the air.

Also, I don't think freeze/thaw cycles would bring up the rocks in your location if they're a foot or more deep. I do believe that you'll have trouble compacting the soil around them if you put too many of them in the hole at once.