# Is it practical to build dirt scrapers instead of skyscrapers?

Buildings are often build on the ground into the sky. Would it be conceivable if instead, we build down into the ground instead? We wouldn't have to worry about wind then. I think we could go farther down than up.

Could a world have this?

• There are a lot of good answers and the answer is technically yes, but most people are not very keen on living underground, despite any perceived advantages. They would want to look out a window at a landscape and walk out the door right onto the lawn. This explains the lack of interest in actually building such structures. – Thucydides Aug 26 '15 at 1:09
• @Thucydides Can't they just look out their window and see the worms worming about in the rich black soil? – PyRulez Aug 26 '15 at 1:14
• @PyRuiez It takes a certain type of person to look out the window and find that interesting.... – Thucydides Aug 26 '15 at 2:03
• Not really an answer, but for the record I'd have no trouble living or working underground. My bedroom (also my computer room) already has dark drapes to keep the light out and lots of corporate workspaces are in windowless areas. It would be one thing if nobody ever stepped foot outside, but you can still have ballfields and camping grounds and so forth outside. Another nice thing about underground housing is they don't have such extreme temperature changes, and are habitable year-round with little-to-no climate control. – MichaelS Aug 26 '15 at 4:16
• humidity, flooding and air circulations are not trivial problems with that sort of structure. Dependence on artificial lights too. – njzk2 Aug 26 '15 at 12:56

## Core-scrapers

Buoyancy is a problem.

The main issue with getting a building that deep is the water table. If you build something deep under the water table and want that thing to be full of air, it will really want to float. This is even a problem with recently buried coffins during floods.

So, if the building is being built where people typically live (that is there is water in range of wells), the buildings can not get very deep before they would simply pop out of the ground. This can be overcome, with engineering, by digging through bedrock (not that easy) you can anchor your building to keep it from floating up.

There are a lot of benefits:

• the temperature is fairly constant
• there is a large thermal sink, good for geothermal power
• high winds are not a concern
• mole people

But they don't overcome all the problems:

• earthquakes are still very dangerous
• flooding can be a big problem
• construction is very difficult
• mole people
• Well composed. The salt mines in Kansas (now used for storage as well as mining) are only about 65 stories underground, have regularly spaced pillars and natural walls, and very consistent temperature. Add some fiber optic lighting and it might keep the mole people away. – DeveloperWeeks Aug 25 '15 at 22:24
• Another problem is ventilation, heavier than air gases such as CO2 and Argon are a greater hazard in a dirtscraper than a skyscraper, in a skyscraper they easily diffuse into the outside atmosphere, in a dirtscraper they would tend to pool in the bottom. – Blake Walsh Aug 26 '15 at 12:21
• flooding can be a big problem that's quite an understatement – njzk2 Aug 26 '15 at 12:52
• @njzk2, flooding could be a big problem, but on the other hand you don't need to dig a well, you're already in one! – Deolater Aug 26 '15 at 17:47
• @BlakeWalsh I'd lump that in with flooding. All heavier than air fluids are a problem, liquid or gas. – Samuel Aug 26 '15 at 17:49

# Yes, and it's being worked on right now.

The Above Below project aims to take a disused mine in Arizona and convert it into a underground building. The terraces of the mine will be covered by a large domed roof, with some skylights and artificial lighting providing natural light. The building will be 900 feet (274 metre) tall deep and 300 acres (1.2 km²) in area.

Here's the before:

Here are two views of the structure:

Here is a detail of the central inverted spire, which is more like what you've imagined:

The "building" must be exceptionally wide for structural stability, and the terraces are important so that there are ways to get up and out of it. Stacking floors vertically would also make for a rather dark "building". Using terraces means that no place inside the "building" is blocked from light.

• This seems about as underground as a building in a valley. Neat pictures though :) – Samuel Aug 25 '15 at 22:26
• @Samuel The graphics are interesting. It could probably be scaled down, though, in which case it would certainly be underground, by any definition. – HDE 226868 Aug 25 '15 at 22:27
• Kind of, I mean building the spire then filling in around it with dirt. The existing plan leaves it open to the air. – Samuel Aug 25 '15 at 22:35
• 900ft isn't exactly a ground scraper though. Not if we're comparing with skyscrapers. – chasly from UK Aug 25 '15 at 22:43
• @chaslyfromUK 900ft is good enough by far to be a skyscraper (see here). – HDE 226868 Aug 25 '15 at 22:45

Yes, they are called mines.

The TauTona Mine or Western Deep No.3 Shaft, is a gold mine in South Africa. At 3.9 kilometers (2.4 mi) deep it is currently home to the world's deepest mining operations rivaled only by Mponeng gold mine with which it competes for #1 ranking.

This goes more than twice as deep as the tallest building is high.

Whether anyone would want to live there with journeys of up to an hour to reach the surface, is another matter.

• Sure, the shafts are deep, but are they wide enough to be like skyscrapers? – HDE 226868 Aug 25 '15 at 22:07
• That wasn't specified in the question. However they could be made wide in the unlikely event that anyone wanted that. Do you have any figures for a standard skyscraper width? ;-) – chasly from UK Aug 25 '15 at 22:09
• I thought it was implied, my bad. No, I have no idea what the standard width(s) is/are. There are probably lots of variations. – HDE 226868 Aug 25 '15 at 22:10
• These days the tallest buildings taper towards the top. It would be much easier and structurally more stable to invert a tapered shape. en.wikipedia.org/wiki/List_of_tallest_buildings_in_the_world ---> If you look at the Burj Khalifa and then examine its plan view, you'll see that the shape could indeed be inverted. – chasly from UK Aug 25 '15 at 22:19
• The problems of working in a mine are a good set of problems with building a large, underground residence: flooding, ventilation, waste heat, and lighting are the big ones. Many mines need to be continuously pumped out else ground water seeps in. They also need to be ventilated else the air gets stale and workers suffocate from CO2 poisoning, dust, or noxious gas from the Earth itself. Waste heat from any large appliances (washer, dryer, refrigerator, oven) needs to be vented to the surface. – Schwern Aug 26 '15 at 0:43

Yes.

But it has its own problems.

1. The sides will want to collapse in. You'll need to build walls to keep the ground up. An amazing irony since most walls keep buildings up.

2. Natural lighting will be terrible... there won't be any!

3. Drainage will be a problem. Especially if you dig down to the water-table.

• To be fair, if you go down deep enough, there would be some natural lighting from the glowing walls. Air conditioning would be expensive, though. – Frostfyre Aug 25 '15 at 21:58
• @Frostfyre If you dig deep enough you'll find the hidden fun stuff! – Schwern Aug 26 '15 at 0:48
• Natural lighting is not necessarily a problem. These guys (lichtkamin.de) develop so-called "Lichtkamine", which translates "light chimney". What would keep me off would be the lack of sky and weather. Having served on a frigate, often seeing no day light + sky was a pretty non-nice experience. Admittedly, it was enjoyable inside when weather hell broke loose, but in general, no. – phresnel Aug 26 '15 at 9:19
• Maybe this "dirt scraper" would be built if/when climate conditions get bad enough that the weather is generally hell. – Deolater Aug 26 '15 at 17:46

Significant factor influencing "format" of building is what is natural for species which is supposed to inhabit it.

For example with humans, there are many actual biological limitations overlooked in daily life and each of them needs special dealing if going underground. Just name two:

• air – for optimum health, an adult needs 50 m3 of fresh air per hour
• sunshine

• we require exposure for 15 mins a day for vitamine D production needed for basic body functions
• needed for good mental condition, lack of sunshine for couple of months is starter of depressions even for healthy people

Although these CAN be supplied artifically, there is no natural thinking in human species to go underground. We naturally feel best at ground level, with home surrounded by nature area (e.g. garden, lake, sea, etc.). Most of people can easily verify it on themselves by imagining "where I would live if I had \$100M". I doubt that popular answer will be "in dream appartment 25 floors underground".

Of course, in your world you can always stylise people living underground if

• conditions on the surface are no more suitable for healthy living
• surface is overcrowded – living above the ground has became privilege only for richer people, where workers, or various poor people are pushed into underground buildings (with many homes there not in good condition), which often provide unhealthy but affordable living for lower classes

Yes. There are already very deep mines. There are also liveable military bunkers and even self sustained nuclear fallout shelters built under ground.

The main problem is that these buildings are More expensive per square meter of floor space than an above ground building. The reason being that before they can be constructed, the earth needs to be trucked away and dumped somewhere. You are not going to find enough land to dump all that dirt within 100 km radius of a major CBD. Notice that that in the examples above people are trying to build on top of an existing mine out in the wilderness somewhere, not build a high rise office building in the city.

In the anime Neon Genesis Evangelion Tokyo 3 is built on top of a "cave" (not the right term probably, it's bigger than the city).

When the enemies attack the city's skyscrapers retract underground, sticking out in the empty cave. There is artificial light (as bright as daylight) and the bottom of the cave is like a big garden (well, more like a forest).

• Unfortunately NGE is an anime which doesn't put much thought into plausible physics. – Philipp Mar 22 '17 at 15:47