How hard to dig 50 feet underground

[binabik]

I don't know anything about digging holes to put say 5 stories underground and was wondering how hard it is to dig two different sized holes.

 

these will be open to the top and at least this big, all the neccessary infrastructure for the machines to go in and out or anything.

 

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

 

it can be bigger if need be i just need to know how hard this would be to dig, maybe how much it would cost and the vehicals that might be needed, though the difficulty is the main thing though.

 

P.S. This does have something to do with archetecture i just don't feel like talking about it yet.

[Moontanman]

I don't know anything about digging holes to put say 5 stories underground and was wondering how hard it is to dig two different sized holes.

 

these will be open to the top and at least this big, all the neccessary infrastructure for the machines to go in and out or anything.

 

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

 

it can be bigger if need be i just need to know how hard this would be to dig, maybe how much it would cost and the vehicals that might be needed, though the difficulty is the main thing though.

 

P.S. This does have something to do with archetecture i just don't feel like talking about it yet.

 

How hard it would be to dig a hole, any hole is directly related to where you dig the hole. How hard is the soil/rock and how high the water table is. Where I live it would close to impossible to dig a hole that big, water and sand would wash in continuously until all you have was a large pond with sloping sides!

[binabik]

well i don't know where it will be but let's say it is above the water table the whole time and i have the best equipment for the job and feel free to list all types of soil and rock, i really just need a simple answer compared to other types of big holes. what i am planning, though no formal training and i doubt the idea will ever come to fruition, is to dig the hole and then drop some prefab units in there of my own design

 

EDIT: Oh and i am then gonna cover it back up

[Moontanman]

well i don't know where it will be but let's say it is above the water table the whole time and i have the best equipment for the job and feel free to list all types of soil and rock, i really just need a simple answer compared to other types of big holes. what i am planning, though no formal training and i doubt the idea will ever come to fruition, is to dig the hole and then drop some prefab units in there of my own design

 

EDIT: Oh and i am then gonna cover it back up

 

I'm not an engineer but I would have to assume that sand would be easiest to dig up and granite or basalt would be the most difficult. I've given some thought to building under ground but you would really have to decide where and then adapt to the physical characteristics of your site. The variables for every type of situation would be far too large to list.

[Thunderbird]

When my father and I wanted to dig a big hole on the property we dug holes with post hole diggers down to 4' place a large coke cup, 32 ounces, filled with SLURAN basically it's fertilizer and fuel oil mixed together, embedded within the sluran, a TNT primer cord, a blasting cap on the end of 5 feet of waxed fuse.

Now here’s the fun part, after filling in the hole with the explosive , place the largest and longest green oak log you can find upright over the hole. Yell fire in the hole!!! Light the fuse, and walk, don’t run to a safe distance, 100 yds behind the truck. What you see is a sudden red jet of clay shoot up along with muffled BUMP sound instead of a boom. The log redirects the explosion down further and excavates a rather large hole. The fun part is watching the 400pound log slowly turning 300-400 ft in the air before falling back to earth.

[modest]

In all likelihood you'll hit bedrock before 50 feet. So, moontanman is right, this all depends on the particulars. If you're building a foundation and need to hit bedrock then this would be no more expensive than any normal excavation. If you need the whole 50 feet and you've incidentally got bedrock in the way then the cost would be enormous. What kind of bedrock, how thick, ect depends on the site and could not be properly priced without a civil engineer or contractor doing a proper inspection. How much does it cost to dig a 400 x 50 foot hole just isn't so easily answered.

 

~modest

[TheBigDog]

If you are going to bury it, then you may not need to dig the full 50 feet. What you put in the hole will take a great deal of the excavated space, and the dirt you removed would pile on top. A structure 50' high may only need a 30' hole to be buried under a mound of the excavated material.

 

What are you cooking up, anyway?

 

Bill

[Zythryn]

Also keep in mind the structure will be under pressure/weight from the surronding earth and the earth on top of it.

Some expense will likely be incurred to support the hole as it is being dug. Unless it is bedrock most dirt will not support a very deep hole.

[DFINITLYDISTRUBD]

And as you go deeper you will need to excavate some form of ramp for the vehicles being used to dig and haul the earth outoutside of the hole...short of using a dragline excavator this is a must...in the case of using said excavator be prepared to shell out several million dollars just to obtain it and have it built on site (no digging yet just purchase and setup) followed by a few thousand dollars for fuel and a few tens of thousands more for labor. (Oh yeah be prepared to wait a couple of years for the draglines components to be manufactured) Odds are using more conventional equipment is just as expensive but would probably be somewhat quicker (a few months vs. a few years). So a few million.

[Moontanman]

Maybe it's a giant end of the world shelter?

[Mercedes Benzene]

Maybe it's a giant end of the world shelter?

 

I've always wanted to build one of those.

 

Anyway, if you're looking to dig a big hole, look no further than the current construction site of the Chicago Spire. They're pretty good at the whole hole thing.

[GAHD]

Good, Fast, Cheap. Pick two. If you've luck you'll get them both.

 

That is your mantra for anything construction related.

 

If you want a "perfect" hole "fast" you can do it "expensively" By using a half dozen front-end loaders, some back hoes, an army of dumptrucks, and dynomite. See "strip" or "pit" mining practices.

 

If you want an "allright" hole "fast", you can do it "cheap" with just the dynomite and a few BIG dozers.

 

if you want a "perfect" hole "cheap" you'll "eventually" get there using human muscle: Is the local penal colony hireing out gangs with picks and shovels? Got buddies who are bored and will do anything for a case of booze? See the low-lifes hanging around the temp-agency looking for tonights party cash? There's NOTHING cheap muscle power can't do, given time.

[DFINITLYDISTRUBD]

If you want an "allright" hole "fast", you can do it "cheap" with just the dynomite and a few BIG dozers.

:naughty: You forgot to mention...and if you want to have lots of FUN:naughty: I love esplosions (but then doesn't everybody:hihi:)

if you want a "perfect" hole "cheap" you'll "eventually" get there using human muscle: Is the local penal colony hireing out gangs with picks and shovels? Got buddies who are bored and will do anything for a case of booze? See the low-lifes hanging around the temp-agency looking for tonights party cash? There's NOTHING cheap muscle power can't do, given time.

I think eventually is the key word here especially using "temps". Where I work we go through temps like they're goin out of style...why?

Because most of them have extremely sucky work ethics and have to have a baby-sitter to make sure that they are doing their jobs.

[C1ay]

These people might have an idea....

[Mercedes Benzene]

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:

[modest]

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.

 

Easy was it? Trying to remember... There may have been a couple deaths involved :naughty:

 

~modest

[binabik]

ok, let me respond to everyone...

 

Montanaman, i don't know exactly the conditions and i have no expierience in this.

 

Thunderbird, explosives are fine, though i would want professional ones, and i would want to be more than 100 feet back behind a truck since something 300-400 feet up can move farther than that and if not more than 100 feet i would want to be under the truck instead of behind it.

 

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.

 

zythryn, see i don't know exactly what to consider that is why i am on this forum asking

 

dfinitlydisturbd, i don't think i want to do a drag line but seeing as i believe for a slightly bigger hole that that i think i can get 2000 or so people fit in with a very small residence, it would be 20x20x10 feet apartments and stacked 20x20x5 so. also since this will be a permenant community i think whatever i do purchase would probably be purchased permenantly so i can expand with the same method. i also thought of a method where i would use a 24 foot diameter Tunnel Boreing Machine and use that to build large expansive of tunnels.

 

montanaman you are close though it is also going to be more like a modern day castle with defensive placements, i am hopeing what i make the structures out and the fact that they are underground would make it so it has protection in the second to worst case scenario if somoene brings for instance artilliary to take me out like in the movie the postman.

 

mercedes benzene that does seemt o have a preatty big hole from the pictures

 

gahd well, it would want it to be preatty percise and not too too expensive though, i do not want to use an army of laborers though that just seems like something i wouldn't want to do and plus eventually i might make another hole like this.

 

c1ay wow, mine is going to be smaller than that buy quite a bit especially on the deep part

 

last thought, i mentioned the Tunnel Boring Machine and if i did this i would buy it and keep using it.

 

thanks more discussion is asked for.

 

 

 

 

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