San Francisco’s Millennium Tower, one of the city’s tallest buildings, is sinking faster than expected during the current modification plan, the Los Angeles Times reported on Wednesday.
The luxury residential tower, known as the city’s “leaning tower,” has reportedly “sunk since construction began in 2006 and is tilting.”
The close to $100 million retrofit project was underway when it was suspended on August 19 after crews made the discovery.
Millennium Tower versus Salesforce Tower.— Paul Kaihla (@PKaihla) August 9, 2021
DATELINE: San Francisco, Sunday August 8 pic.twitter.com/4EjvTHypw2
A spokesman for the building’s homeowner’s association said they are trying to “understand better the mechanisms associated with the increased settlement rate and available means of mitigating this,” adding that “there has been no material harm to the building, and it remains fully safe.”
Why Millennium Tower is leaning, sinking
A previous Los Angeles Times report said the problem with the Millennium Tower “is that its foundation reaches only to a layer of sand, just above a layer of clay, instead of farther down into bedrock,” citing structural engineers.
This type of construction was reportedly popular for San Francisco, but the LA Times other towers built using this method were “much shorter and lighter than Millennium Tower.”
The plan to fix the Millennium Tower
The building’s homeowners association, Millennium Tower Assn., had reportedly announced plans in October for “the engineered retrofit of Millennium Tower to ‘prevent any significant future settlement of the skyscraper.’”
There were plans to install 52 concrete piles — or columns — “that would anchor the building to bedrock, 250 feet below ground.”
During that same time, the association reportedly said that Millennium Tower’s “tilting and sinking had virtually halted over the prior two years,” according to the LA Times.
“The engineering retrofit will provide long-term assurance of the tower’s performance in the event of any future construction nearby and will potentially reverse a significant portion of its tilt,” the association reportedly said.