Millennium Partners, builders of the Millennium Towers at 301 Mission Street in the City by the Bay, have been taking heat from the city and condo owners as their 45-story building has sunk 16 inches and leans 2 inches to the northwest. The 301 Mission building was designed with no support piles and instead rests on a four-level basement garage with a bowl shaped concrete slab that is 12 feet think in the center and 5 feet thick at the edges. The 'bowl' rests on fill from the San Francisco Bay, with nary a bedrock in site.
As the developers face lawsuits and bad publicity, they have decided to redesign the foundation of their newest45-story condo building already under construction at 706 Mission Street. Millennium Partners did another existing soil sample analysis earlier this month.
“We decided to install an additional boring in early October to sample and further analyze the existing soil conditions at very low below-grade depths — up to about 300 feet below the surface,” Millennium Partners spokesman P.J. Johnston said in a statement. “Any foundation design elements that are recommended by the 706 Mission St. engineers and consultants, and that we ultimately pursue, must account for the unique soil conditions at this specific site, as would be appropriate for any building anywhere in the city.”
Debra Walker, a member of the San Francisco Building Inspection Commission, called the developer’s decision to consider going down to bedrock “prudent.”
Read more about the developer's about face here: