Hi, it's been a real long time but I have something I'd like input on. I have the desire to make a nice underground lair. I've done a search and found some underground fort thing, but I have a little more direction, and I want something a little higher grade. I originally wanted to bury a shipping container, but upon research I found out they are unable to support the weight of being buried too deep.

I then found something suggesting culvert pipes, they can come as wide as 20 feet diameter, but I was thinking the more common 10 ft diameter. I want to bury one about 6-8 ft underground, with a ladder descending to it. I'd probably rent a bulldozer or backhoe to dig the earth out, and then roll the culvert pipe in. Then I'd cut a hole in the top, towards one end, or else have an elbow and reducer connect to a vertical one serving as the entry way. I would then either bury it by hand or with the front end loader of a tractor. Ok, seems like I'm rambling, what do you guys think about the feasibility of this idea? (Oh, and I know I need ventilation, there is a company that makes fallout shelters like this, and there is a special ventilation thing for these. here's a link http://www.disastershelters.net/index.php
I'd just order one of these, but I want a more customizable one, and cheaper than what they want.)

Why not bury a shipping container after adding support beams and reinforcement?

It would most likely be the cheapest option.

Well, from what I'd read they suggested if you were gonna do a shipping container, you had to do concrete reinforcement. I just figured that, that'd be more work, than using something that's supposed to be buried. I hadn't thought of support beams, you mean like the ones in like mine shafts, right?

Wouldn't even need supports. Shipping containers can be stacked 11 high. I bet they can handle a foot or so of dirt.

I'm sure they could stand 1 foot, but I'm talking 6-8 foot. I guess I could go shallower, but I'd prefer it to be deep.

EDIT: I also forgot, with the shipping container, I have to figure a way to bury it, maybe having the hole dug, and backing the trailer up, then burying it from their, but with the culvert pipe, it could just be rolled into place. Any other ideas on how to get a shipping container into the hole?

A bunch of burly manly-men carrying it?

Seriously, it can't be that heavy, just ask some of your neighbors to help lifting something heavy.

An empty 40' container (standard ones you see on trucks, trains, ships etc) has a mass of 3,800kg. It is also huge.

There was a thread not long ago about underground tunnelers. It had some useful links.

Good luck!

What would happen if you dug a tunnel without any support for the ceiling? Would it eventually cave in after a couple months due to rain softening the soil?

i thought when shipping containers were stacked, they are stacked in a regular pattern, and the weight is being supported on the perimeter of the top of the container. this part would be strong, as there are the walls of the container to support it. but with dirt, theres a lot of weight being pushed on the center of the roof, which is thin, and there may not be enough tensile strength to hold it there

good point