How hard to dig 50 feet underground

[jab2]

thebigdog i am actually building a survivalist/minimalist community in my head with no schooling, just an idea i like and i don't really want to list details right now but the buildings will be underground about 5 feet that way i can get 5 stories underground and out of the radiation, i would have gone with the 28 stories of stargate command but that seemed like way too expensive.

 

Excuse me for being cynical, but I think you need to think over you "project" a little more.

 

Radiation?? I hope you are not meaning nuclear radiation, cause if you do, you have missed the bus by a few decades. The nuclear arms race is past, man. The only radiation that is currently or in the near future of danger to humans are the sun's UV radiation and for that sunscreen is sufficient.

 

But to come back to your original question. Building something like 5 stories underground can use serious money for excavation and construction. Like a previous poster has said, you cannot expect a flimsy wall to hold the earth from outside without collapsing. You will have to have rather thick rebar concrete retained walls. Then there are the question of water ingress, even if you are above the water table, as you will get water from rain. So you will have to seal the walls. If you are worried about nuclear radiation you are also looking at a serious air supply and filtration system. Then what are you going to do for water and food supplies? For 2000 people you would have to store about 10 000cubic meter (or 10 000 tons) of water per month. And that water will eventually end up as black or grey water, so you have to do something with these. Then there is power supply, for lighting, heating and cooling.

 

You talk about underground, but then you want defence placements like a castle. These are normally above ground where the defenders can see their attackers and mount a defense, completely negating your "underground protection" goal as you have two choices of manning them. Either seal your defender permanently out to dye or leave your structure open to NBC agents for everybody to die inside.

 

"Stargate". "Like in the movie Postman". ??? Me think you watch too much TV and movies. Try and visit a real construction site and learn a bit. What you want would not be as easy as in the movies. :)

[GAHD]

gahd well, it would want it to be preatty percise and not too too expensive...

you just gave up on fast ;) figure out who can run a loader or a hoe for gass money and some booze..they're out there.

 

would it be easyer to (dig) lots of small 20feet by 20feet by 10 feet holes, though this would be more spread out.

digging is digging.

 

Radiation?? I hope you are not meaning nuclear radiation, cause if you do, you have missed the bus by a few decades. The nuclear arms race is past, man. The only radiation that is currently or in the near future of danger to humans are the sun's UV radiation and for that sunscreen is sufficient.

Nuclear war is every bit a reality now as it was 20 years ago; just because you fail to realise there are still people manning "the button" in various countries day in and day out does not mean that they are not there. That is reality, come join it sometime.

 

But to come back to your original question. Building something like 5 stories underground can use serious money for excavation and construction. Like a previous poster has said, you cannot expect a flimsy wall to hold the earth from outside without collapsing.

This is what trussing and cross-bracing is for. No wall need ever be wider than 6" with appropriate buttressing. Given the small cubicle nature of the rooms I don't think you'd need that much support.

 

*if you had the rooms arranged in a manner othe than 90 degree joints, preassure could be more evenly distributed. A "honeycomb" of 2-4" concrete could very well do it.

 

Then there are the question(s) of water ingress...air supply...water and food...power supply, for lighting, heating and cooling.

Valid points. Any Ideas? SOunds like fruitful grounds for a new thread.

 

Try and visit a real construction site and learn a bit.

:eek_big: oxymoron.

[LaurieAG]

first hole is 50 feet deep, 400 feet wide, and 400 feet length.

 

second hole is 50 feet deep, 400 feet long and 40 feet wide

 

Hi Binabik,

 

I worked with geotechnical engineers in the 1980's digging test pits for road building materials. These test or borrow pits were about 100M long, 20M wide, about 10M deep and were dug in extremely weathered sandstone.

 

The equipment used was one Komatsu (equivalent to a D9) bulldozer with rippers on the back. The operator could dig the hole in the morning and fill it back in in the afternoon after the samples were taken. The time taken just depends on how neat you want the holes.

[Michaelangelica]

Where's Buffy?

She'll tell you how to make a REALLY BIG hole. Big enough, in fact, to swallow an entire city. It's pretty easy. [see Sunnydale for reference]:naughty:

LOL

Sorry no rep allowed. (mean system again)

 

binabik

Move to Coober Peddy

Coober Pedy - Opal Capital of the World - Outback, South Australia

It has been the site of most Post-Apocalypse movies!

 

I have always wanted to live in a hole. I think it was the influence of Phantom and Batman comics. Unfortunately I married a claustrophobic.

 

 

One of the big problems in living underground is keeping it dry. Waterproof membranes have improved a lot in the last 10 years but not as much as their advertising hype.

In Coober Pedy water is not a problem as there isn't any.

[CraigD]

Conventional “dig a hole” construction excavation is intended, with the occasional exception, to make a foundation hole for an above-ground building, so I think this is the wrong area to be looking toward for guidance in building a fallout shelter.

 

Large fallout shelters projects, if not commonplace, well understood and have been successfully completed since at least the 1940s. Perhaps the most famous is the “Congressional Bunker”, built from 1959 to 1962 on the grounds of the Greenbrier hotel in White Sulphur Spring, WV, at a then cost of about $86 million (about $640 million in 2008 dollars), and reported to currently cost about $3 – 4 million/year (about $500,000 in 1960 dollars) to maintain. It's designed to permanently house about 800 people.

 

You can nowadays tour the Greenbrier and its fallout shelter. Even if you skip the shelter, the food alone is, in my and the opinion of every food critic I’ve read, worth the trip. :cheer:

 

The engineering to build large fallout shelters like these is essentially mine engineering, the equipment and labor needed about the same as that needed to operate a shaft coal mine. As it’s easier and safer to excavate and build horizontally than vertically, large shelters like the Greenbrier’s usually have sprawling single story, rather than “stacked” multi-story floorplans. Exploiting local topography by having an entrance at the base of a mountain, avoiding the need for long or steeply sloped passages or vertical lift shafts is another advantageous approach seen at the Greenbrier.

 

Since you’ll likely need to buy the land on which you build anyway, I think the most cost-effective way to make a large fallout shelter would be to buy land that already had an abandoned shaft mine on it, unseal the mine, and expand and build (mines have no interior concrete walls, usually less than comfortable ceiling height, and are generally unpleasant living spaces) the old mine galleries and tunnels. My rough guesstimate is that you could reduce you total cost from about $1 million/inhabitant to a few thousand.

 

I’d strongly recommend budgeting a few $10,000 to send one or more of your people to a mine engineering college, or a few $100,000/year to contract with a professional mine engineer – mining is a dangerous profession for the best trained, and a nearly suicidally dangerous one for the poorly trained. :phones:

[Mercedes Benzene]

Or you could always buy a cold war-era missile silo. If you search around on the internet, you can find plenty of those for sale. It's always been my intention to buy and refurbish one of those, but they're always in random places like Kansas, Wyoming, etc. The idea however, of owning your own missile silo is tempting.

 

Here are some examples, with properties for sale. Missile Bases :: 20th Century Castles, Unique underground properties.

[binabik]

Sorry i haven't replied in a while, i am not too good with forums.

 

jab2 when i posted this i had just started really thinking and planning it in my head less than two days before so i know i need to think and ask lots of questions.

 

it is not neccessarialy about radiation, it is mainly just a community that is a little be more protective and defenseable, and if 2000 people live underground that is 2000 people that are in less danger from flying bullets or artilliary.

 

i am assumeing that if i built it i would build it to withstand what ever it needs to i just don't know what it needs at the moment. ditto for water from rain. for air supply i have heard that there are simple solutions, though i don't know if this is true, like filtering the air thought water or something. a cubic meter of water weighs 1 ton? hum cool fact. i have heard of some underground shelters with wells in it or i could some how put water conservation laws or something that people would have to follow or get kicked out. For the black water and grey water i assume there is some way around this i just am not thinking about this, mainly the hole part.

 

for the defense i was really kind of thinking something like pilboxes or half submerged bunkers that you could shoot out of without endangering yourself, actually i have seen this one tank design where you could shoot an ak47 out of it and it still be sealed against nuclear, biological, and chemical weapons, and like i said though this is not neccesarrily going to be for nuclear or the like thing, i am thinking that economic disaster is most likely.

 

Yes i watch too much movies but in my opinion i feel i can decide what i think is possible and not possible, like artificial gravity is possible but not by a generator unless that generator is something like the revolving thing. and yes i know it wouldn't be as easy as in the movies. but i draw alot of my inspiration from fiction and history.

 

 

next post

 

gahd i don't know how percise it would need to be but no matter what i think it would have to be backfilled in and if that is the case than it can be as unpercise as needed as long as i can fit what i want to fit in.

 

i do agree that nuclear war is pssible and one of my teachers (i go to college) said that he believed there will be at least one nuclear explosion on american soil within the next 10 years.

 

i will make the structure inside as ideal as possible and since i am going for small spaces for each person and little possessions yes it will be small rooms.

 

here are a couple ideas i am gonna throw out there, for food each person could have some sort of grow light gardening or make some sort of underground farming that we can immediatly replace with replicators when they come to the civilian market (just joking i don't have much faith in replicators becomeing reality), powersupply i don't know what is best though since you are already 50 feet down i think something like geothermal would probably be best, also for heating and cooling you are underground with perferably enough thermal insulation to keep it a good temperature and with small systems that are run every once in a while.

 

next post

 

laurieAG thanks for that answer, though i will assume they were expierience to be able to excavate 20000 cubic meters of earth that quick, at that rate one guy could excavate the 50x400x400 in feet hole in less than 12 days, if this were possible, and i don't doubt you, i could excavate 3 of these per month, which would be good

 

next post

 

michaelangelica

 

i used to want to live in a hobbit hole, but then i decided to think bigger, heh, though if someone gave me one even if it was a small hobbit hole i would take it in a heartbeat. I am not big on comics or phantom, or batman so heh.

 

here is a thought, if you did have to worry about water and you couldn't stop it all you can at least keep it dry with dehumidifiers or you could some how design it to seep in and either be collected or let alge grow or something, won't be enough for everything but if you design the wall to withstand seepage it would be alot better off then if you built a wall that would be destroied by it.

 

next post

 

CraigD

 

another good post in my opinion

 

you mentioned the cost to maintain, if i had 2000 people living in it and it cost even double that then someone would be able to live in it for less than 10k a year, i think i have heard rent in NYC can be higher than that for a common apartment

 

I have thought about mine engineering and even tunnel engineering, like buy a tunnel boreing machine and just keep it running, if you do do something like this i could make it so you can easily get excersize by running around the complex, you know even as much as 4 mile loops heh. When i was thinking about the stacked multi story i was mainly thinking of simplicity in digging the hole and of course infastructure would be esy, and i was also thinking that some skyskrapers i think have 5 basement levels underground so i figured 50 feet down would be an easy enough distance down and decided to come here to find out.

 

Yeah i think that would be a good idea to buy an old mine, they seem plentiful. mines may have no interior concrete walls, usually less than comfortable ceiling height, and are generally unpleasant living space that doesn't mean that you can't add concrete walls, for safety as well as to make the walls uniform and easy to build upon, it doesn't mean you can't make the ceiling higher as needed, and if you do this, make it so that the walls aren't dirt, and the lighting is good and bring plants and stuff in then i think it would be better to follow this approach. since i would be making it safer and more pleasent i would think it would still cost a pretty penny to make it.

 

i actually will never mine myself since i do think it is extremly dangerous but if someone was going to live permentantly i would have to make it so that it is practically guarenteed to not cave in.

 

and either sending some people to school or spending more money i think that i would rather have the previously trained and with expierience guy rather than the fresh from school guy, or maybe a mix.

 

and last post

 

mercedes benzene

 

you know that would be good but if you bought that most of the systems i would think would be taken out and restoreing it could take a lot of money especially to make sure it doens't have residual radiation or radon problems, or led or heavy metals or all that stuff that could potentially kill if exposed a while and yeah that would be cool to own. also the reason i believe they are in kansas and wyoming is because they are out of the way. bad part is if some nuclear war does start most of the missile silos i would think would be known to the enemy and potential direct hit targets by nukes.

 

by the way have you heard of the cyber bunker, don't know if it is still operational but it actually has computer servers and i think an advertisement was like, your files will be safe even if the internet is obliterated and turned to dust or something like that. here is the link Welcome to CyberBunker it says it has lots of water storage NBC air filtration, power, designed to survive a 20 megaton nuke from 5 kilometers, 5 meters thick reenforced subtereneon construction, air tight rooms, emp protection, heating and cooling, airlocks, and 5000 cubic meters of area, it originally in 1955 cost 250 mil though and i don't know how many people it is supposed to hold but it says it is designed for 10 years isolation.

 

well thanks for the info, lots of good information and sorry for taking so long to reply like i said i am not very good at forums.

[Tolouse]

you know, this is an appealing endeavor that i am also quite interested in

[binabik]

it may be an interesting endevor but i don't think it will happen any time soon

[max4236]

You'll need to find a way to pipe sunlight down there too or the people will go crazy, mutate, and start sneaking around the surface at night, eating the inhabitants left above ground.

[Moontanman]

You really need this ! then you find some expert helps . And if you find for this matter. Please tell me i also same issue for my home.

 

You are not providing enough information to get an answer. Fifty feet under ground where? Where i live it would be easy to dig 50 feet under ground, but all you would be doing is digging a 50 foot deep pond. Our water table is almost at the surface, in the Midwest is would be relatively easy, in the mountains very difficult. You have to know the conditions of where you want to dig before you can even begin to know how difficult it will be.

[mainah]

Just go out and buy a missile silo from Uncle Sam.