3 ms·

> The normal process is to drive piles down to bedrock. Citation needed. Friction piles are quite normal too. I've lived in buildings in SoMa that used frictio

> The normal process is to drive piles down to bedrock. Citation needed. Friction piles are quite normal too. I've lived in buildings in SoMa that used friction piles and none of them were tilting as much as this building. There's something more going on here (design or construction flaws), but it isn't as simple as "friction piles bad". https://sf.curbed.com/2016/9/15/12930402/millennium-towner-sinking-foundation-buildings https://sf.curbed.com/2016/9/15/12930402/millennium-towner-s...

dehrmann 5y ago
A few years ago, one of the theories was construction of the transbay terminal caused this, but I have no idea if that was actually the case.
- jeffbee 5y ago
  You can imagine why they floated that idea but the site is surrounded by other buildings which survived intact, including a 100-year-old unreinforced brick building.
throw03172019 5y ago
Is it normal for the size of the building + use of concrete over steel (increased load)?
- diebeforei485 5y ago
  In other parts of the world, far taller buildings are constructed using friction piles[1]. Again, friction piles are not unusual at all. Drilling into bedrock happens in parts of Manhattan[2] , but that's because the bedrock is generally close to the surface. Whatever's going on with Millennium Tower, it's not "friction piles bad". 1. https://youtu.be/N5i3UsiSoYY https://youtu.be/N5i3UsiSoYY 2. https://buildingtheskyline.org/bedrock-and-midtown-i/ https://buildingtheskyline.org/bedrock-and-midtown-i/
ylee 5y ago
>Friction piles are quite normal too. I've lived in buildings in SoMa that used friction piles and none of them were tilting as much as this building. A selling point for my old condo building in SoMa is that it's one of the few buildings there that is built on bedrock.
ericbarrett 5y ago
The piles they used for the Millennium Tower were the same length—80 feet[0]—as those they'd use for a 22-story highrise on, say, 6th St. Millennium Tower is 58 stories and right on the water. [0] (PDF, pg. 2) https://sfdbi.org/sites/default/files/Millennium%20Tower%20Safety%20Review%20Report%2007.28.17.pdf https://sfdbi.org/sites/default/files/Millennium%20Tower%20S...

dehrmann 5y ago

A few years ago, one of the theories was construction of the transbay terminal caused this, but I have no idea if that was actually the case.

jeffbee 5y ago
You can imagine why they floated that idea but the site is surrounded by other buildings which survived intact, including a 100-year-old unreinforced brick building.

throw03172019 5y ago

Is it normal for the size of the building + use of concrete over steel (increased load)?

diebeforei485 5y ago
In other parts of the world, far taller buildings are constructed using friction piles[1]. Again, friction piles are not unusual at all. Drilling into bedrock happens in parts of Manhattan[2] , but that's because the bedrock is generally close to the surface. Whatever's going on with Millennium Tower, it's not "friction piles bad". 1. https://youtu.be/N5i3UsiSoYY https://youtu.be/N5i3UsiSoYY 2. https://buildingtheskyline.org/bedrock-and-midtown-i/ https://buildingtheskyline.org/bedrock-and-midtown-i/

ylee 5y ago

>Friction piles are quite normal too. I've lived in buildings in SoMa that used friction piles and none of them were tilting as much as this building. A selling point for my old condo building in SoMa is that it's one of the few buildings there that is built on bedrock.

ericbarrett 5y ago

The piles they used for the Millennium Tower were the same length—80 feet[0]—as those they'd use for a 22-story highrise on, say, 6th St. Millennium Tower is 58 stories and right on the water. [0] (PDF, pg. 2) https://sfdbi.org/sites/default/files/Millennium%20Tower%20Safety%20Review%20Report%2007.28.17.pdf https://sfdbi.org/sites/default/files/Millennium%20Tower%20S...