re: San Francisco Landmark, Luxury High-Rise Millennium Tower Is Sinking Fast

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Seems odd that it would pass inspection.

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There are Kenny Matasa's all over the place. Slide a shitty politician a few hundred thousand and you could build the empire state building in the Atchafalaya on top of a few pontoons.

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In fact, the Millennium Tower sits on an area of mud-fill. It is not steel-framed, and instead relies on shear walls, columns and beams. The building is anchored over a thick concrete slab and its pilings extend about 80 feet into dense sand, not into the bedrock which lies about 200 feet below street level.

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Seems real safe in an area that has earthquakes quite frequently.

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I read somewhere that engineers that design buildings in earthquake prone areas, actually use this technique so if an earthquake does strike, the building 'rolls' with it, for lack of a better word. Steel fails in earthquakes.

A high rise building is the last place I would live in a city like San Francisco... Especially knowing the foundation was not drilled into bedrock.

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actually use this technique so if an earthquake does strike, the building 'rolls' with it,

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I'm no engineer and its been a while since I've stayed in a Holiday Inn Express but I was thinking the same thing. Bedrock moves during an earthquake so drilling pilings to sit on a bedrock in a fault zone seems unwise....but I really have no clue what I'm talking about.

So they literally built a 58-story hi-rise on sand?

I'm no engineer, but even I know you have to get to bedrock for a building that size.

Question: if that building has sunk 16 inches, how has that not broken utility service into the building? I don't know of a lot of pipes/cables/wires that go into buildings with that much slack for 'settling'.

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Millennium Tower officials say the sinking was triggered by excavation work for the nearby Transbay Terminal. But Transbay officials point out that the tower had already sunk by ten inches before the Transbay dig began. They blame the problems on the way the high-rise was built.

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a lawyer's delight!

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So they literally built a 58-story hi-rise on sand?

I'm no engineer, but even I know you have to get to bedrock for a building that size.

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Many many high rises are on mat foundations, especially in cities where bedrock cannot realistically be reached (Houston, Chicago).

They key word that should have been redflagged is "fill"

Yep, "fill"

I grew up in a Bay Area house built on fill. Stuff was like jello. The driveways, sidewalks and foundations cracked with quickness. That's a real problem with radiant heating!

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sanctuary city ran by democrats.

They got what they asked for imo.

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Building codes? We don't need no stinking building codes? Cash please.

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Very odd. Seems downright criminal to build a high rise in San Francisco fill without anchoring it into the bedrock.

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That's a purely design call. Depending on high it is two inches leaning in any direction isn't that big of a deal. There are high rises in NYC which drift far more than that. The bigger issue is the soil failing beneath the structure. They are lucky it's sand and not clay which suffer from liquefaction during earthquakes.

To give some comparison the Shell building in NOLa doesn't go all the way down to bedrock, and it faces considerable lateral winds (but not seismic loads). I could see this being justified on paper (for the piles not going to bedrock) depending in how the math played out. As always it comes down to money. Excavating and driving piles an additional 200 feet likely would have busted the construction budget.