how to dig a 24" dia 15' deep hole

[pierhogunn]

Any thoughts on this one? need to make a hole 24" dia, and 15' deep, line it with a 6mil poly liner, and then put a heat exchanger in it made of aluminum...

also, how would you seal the top of the bag, it will be right at, or above ground level, covered with a well top

on second thought, how about just a 12" or 16" dia hole?

[crokett]

Only way I can think of is drill it, but would need a well driller or similar boom truck with a big auger bit to go that deep. I'd imagine something could be rented but it would be expensive.

[docrowan]

I don't see how you have any choice but to hire it done.

[pelligrini]

A post hole digger with some really long extensions?

For that size, a pier-rig would be in order. Like the ones for foundations. It'll be expensive for just one hole, you'll be paying travel & setup costs too.

[pierhogunn]

that's what I figured, but I wanted to get some other opinions before I told my friend that the overall idea isn't feasable

[mineengineer]

What kind of ground?

What kind of strata are you drilling into? Dirt or backfill is easy, start getting into the harder rocks and you are talking a lot more time to do the hole. I haven't seen too many 24' holes lately, biggest Ive seen in a while were 18" by 240 foot deep blastholes that take a day each to drill. Like Crockett said.....look for a well digging company or a company that drills pillings/casons for large building foundations. If all else fails, try to find the biggest set of post hole diggers available and put extensions on them

[pelligrini]

Is there any new construction going on around his location, especially residential? If so, he might be able to cut a deal with a rig that's already in the area. It's a long shot, but plausable.

Also, with the big slowdown in building it might not be as expensive as we think.

[docrowan]

I was thinking of a safety issue. I can't imagine a homeowner digging such a whole in day without a professional rig. It would be dangerous to leave this open and in a neighborhood I would be afraid to cover with plywood - too much danger of kids playing around where they shouldn't.

[Mr__Bill]

Around here they have a rig that looks like a perverted excavator. The auger is about 24" and they line the hole with a flexible plastic culvert and then fill it with re-bar and concrete. They drill down through the less than stable soil till they hit bedrock or something they like. Then they build a house on them or pour a slab on a bunch of them. For your needs, if the ground is not hard pan or rock and the hole will stay there while you put your stuff in and cap it I would think an excavation contractor could drill it in a few minutes. If the site is accesable and you are lucky enough to find someone who can stop between one job and the next it could be a simple and not all that expensive soulution.

The other option is a post hole digger with really long handles and someone else to use it.


Bill

[crokett]

The problem with a post hole digger and extensions is what happens if you hit rock. Plus I shudder to think of pulling that 15' up every time, although I suppose you could lower a bucket, fill the bucket and haul that up.

[Mr__Bill]

The problem with a post hole digger and extensions is what happens if you hit rock. Plus I shudder to think of pulling that 15' up every time, although I suppose you could lower a bucket, fill the bucket and haul that up.

You could always get a small child and lower him down the hole with a little shovel and a pail on a rope.


Anonymous

[Daryl]

If the soil isn't rocky you might use well tile. You dig the first one in and for successive tile, just stack them and then undercut the bottom one with high pressure water. The weight will cause them to keep sinking. You will need a pump too in order to get the water back out.

http://www.concretebuildingsupply.co...php?page_id=47

[Russianwolf]

a spoon and REALLY long arms.

[gjat]

Great suggestions, but they really won't work. Drilling holes like that is what we do to set poles or foundations for poles or structures. Everything from 2'x3' deep to 7' x 45' deep. You only need a boom-auger (dangle-digger) to excavate the hole. Pretty much 15 is close to the max depth you can do with those, depending on soil conditions, water table, and rocks. Give a electrical construction company a call. Anybody who sets wood poles for power or ballfield lighting would have it. If I worked for a small company, I'd probably do it for about $500 cash if there was no major rock, good access, and no water problems and it would take me a couple of hours to set-up, drill, and de-mobilize.

Since you said you could have a choice of diameters, what exactly are you trying to get in the ground?

[jonmulzer]

In the areas of NC I am familiar with from a construction standpoint, it is 3'-5' to rock. That would be your biggest issue.