Abandoned Mine Leads to Sinkhole in Subdivision 1

[TigerGuy]

https://www.kotatv.com/2021/11/10/l...study-shows-all-153-houses-are-uninhabitable/

Time for another lively discussion: Where does the fault lie?

Homeowners have been evicted from their residences, due to an abandoned underground mine opening up right under their neighborhood. I don't have all the details, but I am familiar with the area where this is taking place. Allegations include the mine not being properly closed, engineers designing over the mine, title companies that didn't do proper research on the property history, building officials granting building permits, the list goes on and on.

The reporter says in the attached story that the mine turned the land over to the county or state with the stipulation that it only be used for grazing.

Your thoughts? Go!

 

[TugboatEng]

The entire town of Virginia City, NV is expected to collapse in to abandoned mines at some point. So the locals say, that is.

 

[waross]

How far down is the mine?


--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[LittleInch]

Given that we have no access to any documents, agreements or legal papers they is no way to judge.

The lawyer representing the homeowners will clearly put forward one side of the story.

It does appear on the surface to be a failure of land permitting to allow house to be built over what sounds like a fairly shallow mine. But who is at fault? That's why courts were invented to determine such things.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[FacEngrPE]

Almost the same thing happened at Love Canal.

https://en.wikipedia.org/wiki/Love_Canal

Deed restrictions are a poor way to handle post sale use restrictions.

 

[dik]

I thought lawyers invented courts to give them a job...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Spartan5]

Saw the headline and thought of the other sort of abandoned mine.

 

[waross]

A series of sites will be drilled in two phases in the coming weeks to a depth of up to 150 feet, Anderson said. Engineers hope that core samples will provide definitive proof of the extent of underground voids, as well as the integrity of underground mines, pit mines and strip mines that were backfilled with non-native soil when the mine was closed.

First thought:
At 159 feet, a combination of screw piles and fillcrete could possibly remedy the issues.
Second thought:
If the soil use to remediate the old working is not suitable and is prone to developing sinkholes then filling the existing voids may not prevent future voids and sinkholes.
I understand that drilling has started.
We should know soon.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[xnuke]

I grew up in a town with abandoned underground iron mines. There are sections of the town fenced off, including some with abandoned homes or other structures in them. They are known as "the caving grounds," and in some large sinkholes opened. Some of the fenced-off areas include open pit mines. A county mine inspector inspects each abandoned min annually. No one ever sought remediation as far as I know.

xnuke
"Live and act within the limit of your knowledge and keep expanding it to the limit of your life." Ayn Rand, Atlas Shrugged.
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[LittleInch]

The plot thickens then - the mines were filled in but with not so good material??

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[dik]

Mines should be responsible to return the ground to the pre-development condition and set aside a fund to do this.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[dik]

That didn't come out right... not replace the ore, but leave the mine is a condition that development can occur over.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[miningman]

the fix for this is easy peasy but a little expensive. pump either low strength concrete / sand mix down every hole you can locate or use very finely ground up tailings.......think 200 mesh .

 

[Pud]

I used to live on the outskirts of a town called Walsall - near Birmingham in the UK Midlands.
The whole town was undermined by limestone mining. The council spent a few years pumping fly ash concrete down.
Unfortunately, as the mining started in the 14th century, there aren't many records.
Some outlying areas have no go for building on.


Politicians like to panic, they need activity. It is their substitute for achievement.

 

[spsalso]

If you're going to require mine owners to "leave the mine in a condition that development can occur over", then the owners of the mine will avoid that rather enormous expense by saying they're still mining. A teaspoon at a time. Maybe looking for diamonds with a magnifying glass.

It is unclear to me how what was apparently supposed to be a pasture managed to turn into a housing development. SOMEONE signed off on this being acceptable, right?

A name would be good to see.


spsalso

 

[TigerGuy]

Tugboat - living in Nevada, now, I have heard that about Virginia City. I guess they figure, "so far, so good."

The mining reclamation laws used to require the land be restored to a usable form. Cattle grazing on the prairie must meet that requirement.

Filling an underground mine isn't all that simple. How do you fill the high spots with a fluid such as concrete or grout? So, you will still have the back (top of chamber) of the mine continuing to collapse.

 

[miningman]

Tiger, the answer to your question is simply grout under pressure , preferably with tubes already installed to the high points that allow for displaced air to escape from the high points. Not really that difficult but definitely preferably undertaken by skilled mining personnel rather than desk bound computer jockeys.

 

[TigerGuy]

It would definitely take skilled personnel. The cost involved would be crazy, when you figure in the cost of stabilizing the necessary portions of the mine, blocking the rest off to reduce the volume of grout needed, time involved mapping of where to install the vent tubes, and the expense of the grout placement.

 

[spsalso]

By permitting construction of buildings on top of this mine, the government has accepted that it was safe to do so.

In addition, with the failure of the buildings above ground and the connected failures below, they have complicated any possible remediation that could be required of the previous owners.

One COULD ask if there was any POSSIBLE place elsewhere in this locality that such a building project could have been done, but without the potential hazard of underground tunnels. Is the whole county Swiss cheese?

Should new buildings be suspended from blimps, so as not to run the risk of collapsing still more mines?



spsalso

 

[1503-44]

If the mining company turned over the land with conditions that were violated by the permitting process, it seems clear that the permit process is at fault. To my knowledge it has never been a matter of custom to require mines to fill in their subsurface excavations, which usually fill with groundwater shortly after dewatering stops with mining activity anyway. Grouting what could be miles of tunnels is certainly not practical and restoration laws usually only apply to surfaces conditions.