The 58-story Millenium Tower in San Francisco is sliding along its foundation, according to a report by KNTV. The high-rise, which is the tallest residential building in the city, has been sinking and titling for years and is undergoing a retrofit to fix the issues.
Ron Hamburger, one of the engineers working on the $100 million project, said that the building has shifted along its foundation by about an inch.
“Given the present westward tilt of the building, about 24 inches as measured at the roof, the gap between the two buildings in the east-west direction has widened by about 1 inch,” Hamburger said in a statement.
Hamburger said that the sliding does not impact the “structural safety” of the building.
“We have fully considered this in our evaluation of the building’s structural safety and determined that the building is not at risk due to this movement or any movement likely to occur before construction completion,” the statement continued.
Engineers are working to install 18 steel piles around the foundation to stop the building from sinking and tilting even further. Hamburger said that those piles could also reverse some of the sliding.
“Once the voluntary upgrade is complete, further settlement of the building at the northwest corner will be arrested, some rebound will occur, and slight additional settlement of the rest of the main tower will act to reverse the tilting that has occurred and close the gap between the elevator thresholds in the adjacent podium building that connects the main tower and mid-rise together,” Hamburger said.