When news broke about Millennium Tower’s unprecedented sinking and tilting, due in part to the fact that the megastructure is not secured into bedrock, many people wondered: Who on earth doesn’t build into bedrock, especially in San Francisco?
Well, for starters, the Millennium Tower, one of the country’s most high luxury residential towers, clearly did not. But according to the Millennium Partners, they were neither required nor advised to do so.
Millennium Partners had this to say about bedrock drilling, "Contrary to TJPA’s assertions now, a decade later, 301 Mission St. was never designed, expected, advised or required to drill pilings ‘200 feet down to bedrock.’ "
The building reportedly met all city requirements and approvals. They still place blame on its neighbors, the in-progress Transbay Center.
301 Mission St., like virtually all other large buildings in that part of the city, has its foundations in layers of geological materials within the "Colma Formation," just like 350 Mission, the Marriott, the Meridian, the St. Regis, the Intercontinental, SFMOMA, even 101 California … and dozens of others.
The difference at 301 Mission: It exists in a location where [Transbay Joint Powers Authority’s] massive underground construction work was subsequently performed, by an agency that was obligated to monitor and protect existing structures, and to mitigate any impacts of its work. 301 Mission has settled more than originally anticipated because it was affected by this subsequent construction.
As Curbed SF reported yesterday, the Transbay Joint Powers Authority denied any responsibility with the Millennium Tower’s sinking/tilting issue.
As for other buildings in the area, 181 Fremont is secured into the bedrock. But as for the other buildings? We will update you as soon as they (Lumina, Infinity, et al.) get back to us.
- Salesforce Tower Begins Curtain Wall Installation [Curbed SF]
- Transbay Transit Center [Curbed SF]
- Millennium Tower is tilting, sinking [Curbed SF]
- Millennium Tower [Curbed SF]
- 181 Fremont issues statement in response to Millennium sinkage: ‘We’re drilled into bedrock’ [Curbed SF]