??? Haven’t you heard of seepage, ground water, aquifer ?
Haven’t you seen the results of a retaining wall at Manhatten being holed ? The streets were under water - the basements would all be waterproofed, but the street level wasn’t. What I am getting at is that the wall to the river was the wall of the basement of the building at the edge … and so the water went in through there and went from one buildings basement to the next. The wall holds the river out… Just like the wall/roof does in an underwater tunnel (which are often more of a pipe in the water than a tunnel through rock… there being all sorts of mixes of semiments and water… 1%,10%, 50%… eg Sydney Harbour Tunnel being a pipe dropped to the bottom. )
and anyway since the street level is at river level, the ground water will be just below… well above basement floor, (commonly 5 car park levels deep ? )… and thats just the usable levels.
So … yes the buildings would survive being in the canal area (Veniced)… OF course they would be able to wall in any city, and create dikes, walls, banks, drainage… as long as the pumps can pump out rain and sewerage, and the river/lake/sea/ocean stays below the walls.
The important difference to Venice is that Venice was built before electricity, gas, and sewers. By the time they arrived, the authorities were already aware of the problem.
Did you even read the OP? The part where he says “Assuming that water floods the underground and first floors of a skyscraper, what changes …”
He is explicitly NOT discussing the situation where we build dikes New Orleans-style to keep the bulk water out of the buildings. He want to know what happens after the lower floors have been fully undersea for years or decades.
They’re masonry, not concrete. And under constant maintenance. Any visitor to Venice could probably attest to one or more *palazzi *being hidden behind construction facades during their visit (they seem to have printed facade covers for all the major buildings on the Grand Canal for just such times)
Fire towers are like a building within a building. Frequently in the middle of a building with a horizontal hallway to an external exit door would need to be reconstructed to not exit underwater. Safety codes would at least require life jackets if not actual life boats so people fleeing the fire don’t drown. Storage space for these would require a wider hallway than current regulations require.
I picture something like New New York ala Futurama, where the new city is built above the old one. Once new utilities are built, new streets and sidewalks would also be built above the water, at today’s 3rd or 4th floors or whatever. However, floors don’t align between buildings, which makes setting the new street/sidewalk level difficult, but there’s no reason to believe they’d just leave the streets as canals. The city wouldn’t be able to function at all if everyone needed a boat, even a high-occupancy water taxi to get around, they’re just too slow and don’t have the capacity of the subways and people walking on the sidewalks (streets with motor vehicles have significantly less capacity to move people on a per square foot basis). We’d probably see more skywalks and other elevated connections between buildings, and perhaps the new streets are pontoons of some sort. I see a lot of creative opportunities here.
Back to shoring up existing buildings, the issues of mechanical systems, exits, elevators, and the like have been pretty well touched on already. Also, while salt water is quite corrosive, it’s salt water AND air that cause rust and deterioration. Objects that stay underwater, especially cold water, don’t deteriorate as much as you think. It’s the alternating wet/dry cycles caused by waves or tides that cause such severe corrosion. So it may be the case that existing foundations which are already underground wouldn’t be significantly impacted by having the ocean above them. Even exposed steel or reinforced concrete underwater may be ok for a good long while. It’s the stuff near the water line that needs most of the care and attention. Even if waves are blocked, the natural ebb and flow of the tides and even simply wicking action of concrete and the constantly wet environment in the floor of the building that’s only half flooded would be where the majority of problems arise. Do barnacles protect the substrate they’re attached to? They may act as a natural cement-like coating.
An admission of failure, here, but perhaps as a goad: I’m sure we’ve discussed precisely this in at least one thread on how versions of apocalypse might get played out in cities.
Perhaps prompted by that hodgepodge movie A.I., come to think of it, where such a scene (flooded contemporary city millennia hence) is front and center.
Yes, I tend to forget sea trade/ traffic. But since the OP was about skyscrapers, I thought “offices”, which can be anywhere.
Regarding docks and ports, the Netherlands are trying to build floating platforms. Since ships no longer use wind, how important is the position of the harbour?
In the Annotated Pratchett files, there is a remark that Seattle was built several times over flooded buildings, streets etc. But I have a hard time believing that means that the water floods and stays. Usually, the water floods, bringing mud etc, and then recedes again, and then the decision is made that it’s easer to build on top instead of clearing the muck out. (also, this was probably a time before proper building codes and static loads were known and calculated).
I think that building on top if the water is still there is quite different re the stability. If you use only girders sunk in to the bedrock, it might work, but I don’t know if all skyscrapers fit that.
Not too. But a harbor is useless unless it’s connected to the land-based logistic system.
Tankers can get away with mooring to a small man-made island thingy & connecting into an underwater pipeline network. Container vessels need to come alongside land and there needs to be truck, rail, and/or air transport available to haul the containers or their contents away.
The GW deniers will be amazed at the deadweight economic drag of replacing all this drowning/drowned infrastructure. It’ll be like the mother of all tax increases.
Wow did not even think about fire. Most high rises are relocation not evacuation incase of a fire above the 7th floor. But there is still the large number that be evacuating from the 1st 7th floors if the fire was on the lower level. This could get interesting to solve.
The idea that we’d continue to operate current cities as they go semi-underwater seems silly to me. We’ll dike what we can and abandon any other land the ocean occupies.
So there won’t be a mass sudden abandonment of, say, Manhattan. We’ll just slowly retreat inland to higher ground leaving a ecological and economic disaster area behind. Some areas, such as marinas and wharves may well be able to rise with the sea. Downtowns, residential districts, railways and airports: not so much.
It’s not like has never happened before … the final push out of Doggerland is documented in Roman archives … the Dutch got their “wake-up-call” in 1257 AD … I would venture to guess the pre-historic oral tradition is full of such tales … Atlantis, Noah’s flood, Oroville …
Another point is just how long will these skyscrapers last? … 'cause gee-whiz we should be able to recover the capital costs in the next 500 years … or maybe we’re spending too much money on these things … ten billion dollars doesn’t buy what it used to I guess …
Just how important is New York Harbor? … what is the total value of Manhattan Island? … if these places aren’t worth issuing 50 year bonds to protect, then just let them go like so much swampland … yeesh, in just a short 100,000 years from now it’ll all be under 2,000 feet of solid ice anyway …
Nothing in there about Doggerland whose last remnants were well north of the low countries and sank thousands of years before the Romans got to that part of the world.
This book has an interesting discussion of just how precarious the NYC underground infrastructure is, even now, given constant water seepage from the rivers: The World Without Us - Wikipedia. You’d have to spend many billions to preserve the city in anything like its current state if the sea keeps rising.
