Comment on Would it be better to just have a lot of society be underground?
scarabic@lemmy.world 4 days agoeffectively 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?
iocase@lemmy.zip 4 days ago
scarabic@lemmy.world 3 days ago
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.
iocase@lemmy.zip 3 days ago
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?
WhyJiffie@sh.itjust.works 3 days ago
how do you replace viaducts? Would that need demolishing buildings on top?
grue@lemmy.world 4 days ago
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.
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.
scarabic@lemmy.world 3 days ago
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.
It were just talking purely theoreticals built on a tabula rasa, okay then. Like you said, everything can be hand waved away.