one "hole" of a project

[beeforty]

A while back I was watching the Discovery Channel (maybe?) about sealing off old wells and mine shafts. They hung a tarp down in the shaft a ways and poured mixed up dense type of foam on top which swelled up and formed a plug. Made it maybe 5-6 feet high and then covered up with 5-6 feet of dirt, this was a government project they were doing on abandoned mines or wells.

 

[dfkrug]

They hung a tarp down in the shaft a ways and poured mixed up dense type of foam on top which swelled up and formed a plug. Made it maybe 5-6 feet high and then covered up with 5-6 feet of dirt, this was a government project they were doing on abandoned mines or wells.

Yeah, that was on Dirty Jobs, and they were dealing with one of the
hundreds of abandoned mines in the CA Gold Country. That 2-part
polyurethane foam is amazing....I used it on a roof, and underneath
a floor. Sprayed on.

If the owner of the well decides to explore the well, he can mitigate for
potential gases by doing what sewer workers do: force-ventilate using
a blower and a hose.

 

[Gizmo2]

It would be neat to drop a camera down there and see what is on the bottom.

I'm for that!

i think what im gonna do is dig down about 1 foot or so and pour around the hole with concrete (to stabilize the hole) and bolt one inch plexiglass over it and incorporate it into my walk way. so it will be sealed off yet you can still walk safely over it and look inside it anytime. im also gonna hang some lights down it so i can hit a switch and turn the lights at night or day. but when the time comes, and i uncover it again i will lower a camera down and take pictures to see whats down there and possibly take some dirt samples like you said kebo. i never thought of the old coins being there. like you, i would never go down there, because working in construction and excavating i am well aware of the dangers of confined spaces.

No, we need pictures now!

Very interesting post! And that thing creeps me out! If you've never seen the movie The Ring, you gotta see it now. Great horror movie that incorporates a well. After watching that, you may wonder if there's stuff other than coins at the bottom of that puppy.

Same thought ran though my mind when I saw the OP's post.

 

[tennmogger]

Because this is a well and not a cistern, it'd be unlikely to hold water unless sealed, and that would be a big job and detract from it's neat appearance. Wells by design accept water from porous and permeable strata. In this case the water table has lowered so there's no water, but the porosity and permeability are still there.

I had a close call when I was about 7 yrs old. My brother and I were riding our pedal tractors into and out of a depression in the back yard. My dad was nearby, then suddenly had the realization that ancestors had plugged a cistern somewhere in the back yard. Sure enough, my brother and I were separated from a 40 ft x 6 ft cistern by less than a foot of dirt held together only by grass roots. Dad speculated the cistern was plugged with logs which rotted out.

Even though I am also a fanatic about preserving old stuff, and think your idea to put in lights and a clear cover is fantastic, I'd say plug that hole.

Bob

 

[mojoinco]

CaptPicky's suggestion reminded me of something that might be of value: earth temp heat exchanger. Similar projects are done using much deeper drilling.

Line the bottom, then pipe air through a number of pipes (radiator style) from the house and bring it back inside. Maybe use a heat exchanger to add a layer of protection from noxious gases in the cistern. Or even set a series of pipes in there and back fill. Just an idea, as it might lower your cooling bills for little money.

The pipes used are coaxial: a smaller pipe inside a wider pipe. The smaller pipe is open at the end, air is pushed down one, then extracted out of the other.

You could use it as the air source for your a/c compressor cooling air as the simplest way to do this. And the cheapest bang for the buck. Maybe just manifold a bunch of septic drain/waste/vent pipes instead. Back fill on them if you see any useful results to improve the heat exchange (direct contact of the soil).

28' should be both easy and cheap to build large "U" shaped pieces.

 

[Don87]

The big issue is methane and its effects as it is
a huge liability even if the dug well is refilled.

.

Leonz brings up a very good point. I personally wouldn't stick anything electrical into that hole without first testing for the presence of gases.

The results could be quite explosive.

 

[Harvest Moon]

Anyone know how they used to make these things? Did they really dig a 40' hole and start stacking stone in it or was there a top down way?

 

[crash325]

Leonz brings up a very good point. I personally wouldn't stick anything electrical into that hole without first testing for the presence of gases.

The results could be quite explosive.

Sounds like a good idea. I'd toss a lit match in it and wait for the boom. :laughing:

 

[crash325]

Anyone know how they used to make these things? Did they really dig a 40' hole and start stacking stone in it or was there a top down way?

Rock has to go from the bottom up. Unless you can build rock walls faster than they fall. :laughing::thumbsup:

 

[Harvest Moon]

Seems obvious with stone. I have seen concrete well rings set and undermined all the way down.

What keeps a 40' deep dirt hole from collapsing? Maybe some temporary bracing? Just wondering, never heard how they used to do it.

I have seen a stone well, it's hard to ponder digging in a hole like that.