What are the limitations in building taller buildings?

[Darryl_Lict]

@Exapno_Mapcase

The practical limit for buildings pre-elevator was six or seven stories. The poor were the only people willing to walk up that many stairs to the top. (This model started in ancient Rome.)

Just for the record, Old Town Edinburgh was famous for having some of the earlier skyscrapers which were pretty damn tall.

@Wikipedia

An early modern example of high-rise housing was in 17th-century Edinburgh, Scotland, where a defensive city wall defined the boundaries of the city. Due to the restricted land area available for development, the houses increased in height instead. Buildings of 11 stories were common, and there are records of buildings as high as 14 stories.

That would’ve been a hell of a lot of stairs to climb. From what I was told, they actually chopped off the tops of these buildings when building New Town so that the sun wasn’t blocked so much.

[msmith537]

@Maggie_the_Ocelot

Also, there is the question of tectonic stability.* I personally don’t feel comfortable being up too high, because a small part of my brain is always aware of the possibility of The Big One hitting, and it tends to get noisy and panicky if I get too far above or below surface level. I know that seismic reinforcement technology has continued to improve, but still - given the option, I’d prefer to have as few floors above or below me as possible. I don’t think I’m alone, either. It’s part of why, despite the high real-estate prices, we don’t have many skyscrapers in L.A., nor do we have much subway. The fact that we literally cannot trust the ground we walk on has impacted local archetecture quite a bit.

Actually, I think tall skyscrapers are safer than smaller buildings when it comes to earthquakes. They are designed to flex and sway anyway and as long as the earth doesn’t shake at their resonance frequency, they are usually fine.
Another issue with tall buildings is traffic. How do 5000 people get to and from a single building every morning and evening? Where do they park?

[friedo]

@msmith537

Actually, I think tall skyscrapers are safer than smaller buildings when it comes to earthquakes. They are designed to flex and sway anyway and as long as the earth doesn’t shake at their resonance frequency, they are usually fine.

That’s true. Skyscrapers in LA are rarely damaged during earthquakes. It’s the smaller buildings made out of brittle stuff like concrete that get flattened.

Another issue with tall buildings is traffic. How do 5000 people get to and from a single building every morning and evening? Where do they park?

A lot of these super-building ideas envision people living in residences within the complex. I have to admit, it would be nice to take an elevator to work every morning.

I think if you are going to build a 200-story office tower, the only way to make it viable would be to have a bunch of residential buildings surrounding it, connected via bridges to the sky lobbies. Otherwise it would be impossible to get everyone in and out via the first floor.

[Elendil_s_Heir]

PBS had a very interesting program on supertall buildings a few years ago. It suggested that other than cost and the risk of a terrorist attack, there is no practical engineering upper limit to the height of a building nowadays. Although it would be grotesquely expensive and might never fill up with tenants, you could build Frank Lloyd Wright’s mile-high The Illinois if you were bound and determined to.

You can use a tuned mass damper to offset swaying, vibration and shaking in a very tall building: Tuned mass damper - Wikipedia

A fascinating New Yorker article about a guy stranded in an elevator for almost two days, and how architects plan for elevators in modern office towers: Up and Then Down | The New Yorker

[Maggie_the_Ocelot]

@msmith537

@Maggie_the_Ocelot

Also, there is the question of tectonic stability.* I personally don’t feel comfortable being up too high, because a small part of my brain is always aware of the possibility of The Big One hitting, and it tends to get noisy and panicky if I get too far above or below surface level. I know that seismic reinforcement technology has continued to improve, but still - given the option, I’d prefer to have as few floors above or below me as possible. I don’t think I’m alone, either. It’s part of why, despite the high real-estate prices, we don’t have many skyscrapers in L.A., nor do we have much subway. The fact that we literally cannot trust the ground we walk on has impacted local archetecture quite a bit.

Actually, I think tall skyscrapers are safer than smaller buildings when it comes to earthquakes. They are designed to flex and sway anyway and as long as the earth doesn’t shake at their resonance frequency, they are usually fine.

This is totally true, and even more so for buildings here in SoCal, where they take earthquakes into account whenever a new building of any height is constructed, and where older buildings are very often retrofitted to increase their earthquake tolerance. However, that doesn’t appease the small animal part of my mind. Once that part gets activated, it keeps sending my main brain images of the Northridge Meadows Apartments or the Bay Bridge.

[dracoi]

What about the rock underneath? I have always been told that Paris has no skyscrapers because the weaker limestone under that part of France simply won’t hold a building up.

In fact, this sort of thing was recently repeated in the History Channel’s “How the Earth was Made” series on the geological history of New York - that some parts of the city have taller skyscrapers because they have stronger bedrock, or at least bedrock closer to the surface.

Or is weak bedrock just something that increases the cost rather than being an absolute limit on size?

[yabob]

@Maggie_the_Ocelot

@msmith537

@Maggie_the_Ocelot

Also, there is the question of tectonic stability.* I personally don’t feel comfortable being up too high, because a small part of my brain is always aware of the possibility of The Big One hitting, and it tends to get noisy and panicky if I get too far above or below surface level. I know that seismic reinforcement technology has continued to improve, but still - given the option, I’d prefer to have as few floors above or below me as possible. I don’t think I’m alone, either. It’s part of why, despite the high real-estate prices, we don’t have many skyscrapers in L.A., nor do we have much subway. The fact that we literally cannot trust the ground we walk on has impacted local archetecture quite a bit.

Actually, I think tall skyscrapers are safer than smaller buildings when it comes to earthquakes. They are designed to flex and sway anyway and as long as the earth doesn’t shake at their resonance frequency, they are usually fine.

This is totally true, and even more so for buildings here in SoCal, where they take earthquakes into account whenever a new building of any height is constructed, and where older buildings are very often retrofitted to increase their earthquake tolerance. However, that doesn’t appease the small animal part of my mind. Once that part gets activated, it keeps sending my main brain images of the Northridge Meadows Apartments or the Bay Bridge.

Note - your “Bay Bridge” picture is the Cypress Structure which collapsed, not part of the Bay Bridge. That was actually my commute route at that time. After that, I had to detour through West Oakland surface streets to get to Alameda. The Bay Bridge had a section fall:

[Tim_T-Bonham.net]

@yabob

Note - your “Bay Bridge” picture is the Cypress Structure which collapsed, not part of the Bay Bridge.

And that collapse was mainly the result of a crooked contractor, who skimped on the construction to increase his profits. That structure was built in sections by 3 different contractors; almost all the collapse was in the one section he built. Note that even in the picture you link to, the bottom roadway (which was built at a different time by a different contractor) did not collapse. Even when the top level fell down onto it, is still held.

When a contractor cheats & builds a structure below accepted standards, it’s always at risk.

[Exapno_Mapcase]

@msmith537

Actually, I think tall skyscrapers are safer than smaller buildings when it comes to earthquakes. They are designed to flex and sway anyway and as long as the earth doesn’t shake at their resonance frequency, they are usually fine.

This may be true today, but it wasn’t true until relatively recently. Architects know a heck of a lot more about how to design tall earthquake-proof (or resistant) buildings today than just a few decades ago.