SF’s Millennium Tower has yet another problem
Building is undergoing a $100 million repair to mitigate sinking, tilting
San Francisco’s sinking, tilting Millennium Tower has yet another problem.
A one-inch gap has formed between the 58-story main tower at 301 Mission Street and the smaller 12-story structure, NBC Bay Area reported, citing Ron Hamburger of Simpson Gumpertz & Heger, the project engineer. The gap doesn’t put the building at risk, he said.
“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 to the outlet.
Completed in 2009, the Millennium Tower ran into problems five years later when engineers discovered the building was sinking. That led to a class-action lawsuit between its residents and Millennium Partners, the building’s developer, which was settled in 2018.
The tower has sunk about 18 inches and tilts 22.5 inches to the west and nine inches to the north. Construction to fix the building came to halt over the summer when more sinking was detected.
Now, engineers are moving forward with a $100-million dollar plan to install 18 piles, fewer than 52 piles originally planned, to relieve weight on the building’s foundation and help with the gap between the structures.
The abutting building contains 52 condo units and is atop of a five-level underground parking lot. In 2019, inspectors prohibited use of an elevator that connected the tower because of a widening gap, which has since been fixed. City officials and engineers have said the tower remains habitable and secure even during an earthquake.
[NBC Bay Area] — Gabriel Poblete