Underground housing, underground businesses, etc. Would that be better for the environment + possibly save on energy costs? Also possibly safer in certain scenarios like tornadoes etc.
Potential issues that immediately come to mind are ventilation, earthquakes, and flooding. But it’s not like underground dwellings/basements/etc. aren’t a thing, so maybe those issues have been addressed in ways I’m not familiar with.
There are several underground spaces where people work, and live. Chicago, Toronto both have underground systems. There is a town in Australia that half the people live underground because it’s so hot.
Some issues with underground spaces; it can be expensive to dig the proper tunnels, you have to make sure the geological make up of the area will support the structure, water draining down from above after rain storms can cause issues, and the big one is ventilation, you have to be able to move air through out the entire system.
Coober Pedy in South Australia
Everything you think would be good about underground would be more easily and cheaply accomplished by building aboveground buildings that connect. (Or said another way, by effectively raising ground level to roof level without the expense of digging.)
Underground Atlanta is like this, BTW: they didn’t dig below original ground level; they raised the street grid up on viaducts.
The irony is if you designed a city with viaducts, the savings on ground disturbance and the extension in life for utilities (now high and dry instead of rotting in the dirt and corroding, being hit by fiber-seeking backhoes) pays for the viaduct system itself even if it costs tens of billions for a city.
When your domestic water system now lasts a century instead of 40 years, and leaks can be spotted and repaired from a catwalk, the savings compound over that same century. Apply that to power, gas, heating, cooling, telecom… Plus they stop hitting each other any time you need to dig more than a foot. Now telecom will stop hitting water lines when they go to repair broken fiber that was hit by a new construction excavating a foundation.
A 40 year buried power lifespan that cost $5 billion to install for a city means each year you need to replace 1/40th or your power cables and would annually spend 1/40th of $5 billion, or 125 million.
Those same cables in a utilities rack within a city viaduct system might last 2-3X as long since they’re dry, don’t move with frost heave, don’t experience being driven over by fully loaded semis, aren’t at risk of being hit while repairing something else… They also cost a fraction due to no ground disturbance being needed. It’s the same cost as installing power around an industrial plant in cable trays.
effectively raising ground level
I can’t say I follow what this means. Moving everything we have at ground level up? I understand that this kind of thing has happened historically but only in periods where we barely built a couple of stories high.
I’m looking out over the Tokyo skyline right now and there’s every level of building. How do you get everyone to agree on the one right height?
Consider the following scenarios:
-
You start with a hill, then dig down into it and build a building such that it has a flat green (vegetated) roof at the original ground level.
-
You start with flat ground, build the same building on top of it, then mound dirt up around the sides to form a hill.
Two methods to the same result, right?
But now, imagine that instead of one building, you’ve got an entire city worth of buildings like that bunched up touching each other (no roads between them, just interior corridors). With scenario #1, you’ve still got to do a bunch of excavation for each and every building. But with scenario #2, you only need to do earth-moving around the perimeter of the city (if you even bother). Still the same result, but now method #2 is much, much cheaper.
I’m looking out over the Tokyo skyline right now and there’s every level of building. How do you get everyone to agree on the one right height?
This is a very hypothetical thread, so that’s the kind of issue that could just be hand-waved away as part of the initial premise. But if you want a real answer, that’s easy: “zoning codes.” Cities have absolutely no trouble exercising their authority to regulate building height.
Both of your scenarios seem to start with an empty landscape. When I heard “move the ground level up” I took that to mean that we are starting with an existing cityscape that has a ground level, and everything must be elevated.
If we’re just talking pure theoreticals built on a tabula rasa, okay then. Like you said, everything can be hand waved away.
-
I’ve actually been there. Like I said, it’s a gallery with little depth and does not answer how this would be applied to modern architecture n any kind of scale.
The city burned down which allowed these sweeping changes to happen. The minimum height is set by preventing yearly flooding due to heavy rains and strong tides since the area was filled in tidelands. The maximum was set by the rest of the city and its Hills. This is an engineering problem so you solve it the way an engineer would.
The way you would do this for a modern city is by first considering geography and your design requirements. “How much do we need to raise it and why?” If you only need to fit utilities in there and nothing else your necessary lift isn’t that high. Maybe a few meters. If you want to also cram cars or trains down there so you can build to viaduct top lighter by mandating no cars, and to make it a walkable city, you can set a higher requirement. You’re basically building a bridge that spans the entire city and the same calculus works for a viaduct city as it does for designing a bridge. Your biggest expenses are regrading, foundations, redoing drainage, and routing utilities into the viaduct passageways and abandoning existing utilities in the ground from the old city. That’s all if you can avoid eminent domain or conflicts with property owners.
All of this is obviously way easier to do with a newly built city from day 0, or a city that burned down. The reason it happened in Seattle is because residents were sick of yearly flooding and they needed to rebuild with fireproof materials anyways. So why not solve both?
how do you replace viaducts? Would that need demolishing buildings on top?
Afaik you build buildings on raised foundations and the viaduct decks span the gap between buildings creating a raised “ground floor” above the actual dirt. They eventually do wear out given enough loading cycles accumulating fatigue in the metal reinforcement, but can last a hell of a long time if you keep heavy vehicles off of them.
In an ideal world the viaduct top is for pedestrians or bicycles only, and there’s enough space underneath for logistics to supply businesses from loading docks at their basement. Overhead LRTs would be a natural pair with viaducts since you can just build the LRT piers to put their load path into the viaduct columns (which you also engineer to be larger.) that way you can separate all traffic types by verticality instead of all sharing the same grade.
The big benefit there is the viaduct deck doesn’t fatigue hardly at all. Maybe emergency vehicles allowed up on the deck? Otherwise it’s just bicycles or pedestrian traffic.
It’s much more expensive to build underground.
Yes, but “expensive” depends on what and how you measure.
Do you want to suggest a measurement scheme in which underground building is cheaper? As is I don’t understand your point.
For a single family dwelling (or any structure that isn’t too deep), reduced heating a cooling costs could make building underground cheaper in the long run.
For a large structure that goes deep, I doubt if it could ever be cheaper to building underground.
Do you consider lifetime costs? Do you consider the value of biological services of an undisdturbed land surface and habitat? Do you consider the value of a lifetime of energy savings for heating and cooling? Do we factor climate change opportunity costs? Do you consider the disaster resilience of a subterranian building built once vs the multiple constructions of a tornado or hurricane built and rebuilt?
Sometime what seems cheapest can be the most expensive.
deleted by creator
It works, when designed well enough. The problem is how do you continue to support the above ground structures, if you aren’t as lucky as Chongqing geographically. You have to essentially plan not only all the weight of the structures of each underground level, but also above ground level. That takes lots of highly specialized engineering teams to figure out, which is a huge upfront investment.
Which brings another major problem: Cost. Creating underground structures requires massive mining rigs and blasting and getting rid of the material that comes out and constant review of any potential damage that does when further expanding the city out; all of that costs just so much money compared to normal buildings. If your goal is for-profit development, you’ll never break even.
And of course the most obvious problem, most humans are not mole people and do not want to be underground. Sun-deprivation and outdoors-deprivation have serious mental and physical health issues attached, which are not solved by artificial UV-producing lights or indoor plants.
Not really, no. This is the same kind of silver-bullet thinking as self-driving cars, it may feel cool but in reality the best way to improve things are boring and have been known for centuries if not millennia.
Some things absolutely benefit from being underground, like railways in dense urban areas, but for most things it’s just a ton of effort for not much benefit and introducing a bunch of problems (flooding is only going to become more common in the future).What we should be doing is returning to everything being designed for the specific local environment, stop building everything identically all over the world.
Look at traditional construction and you’ll find tons of small features that together make a HUGE difference, a prime example is how hot places had walled backyard gardens with a fountain in the middle, which basically turns the garden into a swamp cooler.Underground is not necessarily better for the environment. I think if we compared the ideal underground build to the ideal above ground build, underground would actually be worse for the environment.
Think about it this way: The advantages you might get from underground are related to reclaiming ground and comprehensive city planning. But you can reclaim roof space to make up for the ground, and you can get the same benefits from city planning building above ground.
The idea that you’d just leave pure wilderness on the ground level when you build underground is not realistic. You could grow the crops you need right there above it, instead, for example. A certain amount of land is needed to support each person. But either way, people would be going to the surface every day. If you build underground, you’ll also be building above ground.
Meanwhile, underground requires quite a bit more stuff. You have to plan more to manage heat and ventilation. It’s difficult to increase density underground because you can build higher more easily than you can dig deeper.
Think of how energy efficient your HVAC would be, though. Especially once the planet really starts cooking.
AC sure, but not ventilation or heating, unless there’s geothermal energy available. And geothermal sites tend to correlate with low safety underground because of geological activity and nasty gases.
Scarcity of livable land isn’t exactly an issue at this point in time to heavily warrant it.
The tradeoff for resilience in emergencies is that the if the ventilation fails hard enough, everyone who can’t get out suffocates. Flooding, as you guessed, is also a serious probelm. Everything that can flood a basement now floods a living space.
Heat and AC are normally going to cost less, but the cost of construction, maintenance, and modification of the structure are way higher and generally kinda dangerous. Not worth it.
You are not a fan of nature and sunlight, are you?
i am but a humble underground goblin
Mold and humidity, look at people who do that and they have to run a heater and dehumidifier to keep the moisture down. Now you could colocate a nuclear reactor and have built in heating and large scale forced air and that would solve it.
There are indeed places where large amounts of human activity takes place underground, often being metro systems and their associated retail spaces; Tokyo Station in Japan comes to mind as having an underground mall attached to it.
But the same caveats for underground construction of transportation systems also apply to all other underground structures that humans would like to build. Consider the differences between ground conditions in: the San Francisco Bay Area, Denver, and New York City.
The Bay Area is the outlet for major rivers in northern California, bounded by mountain ranges on virtually all sides. The surface is either a thin covering of soil atop this mountain rock, or is a layer of looser soil or mud, made from the sediments carried in by those rivers. This makes for fantastic agricultural conditions but presents a real risk of liquifaction when there’s an earthquake. While an underground structure wouldn’t fall over – because it’s within the ground – it could certainly lose its supports unless it has piles all the way down to the rock. And that’s only buildable on the narrow shoreline region where there’s sufficient depth before hitting the rock layer.
With Denver, it’s basically all rock, so to build within the rock would require blasting it away and building within the hole, or to build normally then bury the structure in fill, so that it’s below grade.
With NYC, it’s a different story because the ground conditions make it fairly easy to dig tunnels and drive piles, and the bedrock layer beneath Manhattan is strong enough to support the weight of supertall-class skyscrapers. On this point, the New York Fed’s Gold Vault is in the basement in Manhattan, precisely because the volume of gold inside would be a serious strain on any foundation and the geology beneath.
All that said, the surface conditions in some extreme climates may warrant building underground, or avoiding the underground outright. Burying a dwelling in New Mexico would make a lot of sense, due to the hot and dry Southwestern climate. But in Alaska, an underground dwelling would cause melting of the permafrost layer below, resulting in a similar situation to liquefaction. I suppose this can be mitigated, but it would be a monumental effort, akin to Camp Century in Greenland. That project was abandoned due to changing ice geology.
Morlocks
I certainly enjoy my pandemics trapped in a network of caves full of infected people.
Digging more than a few meters for a building is not only expensive, it can be very difficult and dangerous for the buildings a few hundred meters away, depending on the nature of the soil.
There is a certain cursed railstation project in germany, where the nee railstation is build underground. Though the soil is a specific type, which sucks up any water it gets in contact with and then expands. If there is a significant leakage, we are talking about half a meter difference at ground level for the complete neighbourhood, probably very inconsistent. Building typically don’t like the ground moving that much. So you start investing billions more into the project to make it water tight and still fail to do so.
And after many years you are still not finished and the project seems to be a coup by the car lobby to discredit travel by rail.
Halfing the number of platforms certainly doesn’t help either.
There’s currently a lot of support to finish building the station and keep the old station open anyway. Traffic has increased after all. But they already sold the land the railway switches of the station sit on.
