Sinking tower’s solution
Proposed fix to stop luxury high-rise from going ever lower — drill new piles all the way to bedrock
A fix appears to be in the works for San Francisco’s sinking and tilting Millennium Tower — just as a new report estimates the 58-story luxury high-rise has sunk yet another inch in the past seven months.
City officials and other sources familiar with the situation tell us that the building has now dropped 17 inches since construction got under way in 2005 and continues to descend into the bay fill at Mission and Fremont streets. The sinkage is more pronounced on the northern side, the direction in which the tower is leaning, said the sources, who spoke on condition of anonymity because the Millennium’s problems are the subject of numerous lawsuits.
That lean is now up to nearly 14 inches at the building’s roof — an additional 2-plus inches more than the tilt measured in January.
The good news for the tower’s well-heeled residents, who paid from $1.6 million to $10 million for their condominiums, is that a pair of engineering firms hired by developer Millennium Partners and other parties involved in the dispute think they have a solution that will stabilize the tower and prop it back
upright.
The firms, Arup Group and LERA, say the problem can be remedied by drilling 50 to 100 new piles down to bedrock from the building’s basement. Each pile would be anywhere from 10 inches to a foot in diameter.
After we first reported the Millennium Tower’s problems in August, the developer insisted that its decision not to anchor the foundation to bedrock in the first place had nothing to do with the building’s sink and lean — and that the ground under the building had been destabilized by neighboring construction.
The high-rise’s 900 piles now descend 60 to 91 feet — well short of the 200 feet to bedrock.
The engineering firms estimate the fix will cost $100 million to $150 million — more than your average home foundation repair, but a lot less than the billion-dollar-plus price tag that some experts have feared.
Like so many other things involving the slow-motion fiasco, just who would pay the bill would be the subject of negotiation, and possibly litigation, involving Millennium Partners, the homeowners association and the public agency building the Transbay Transit Center next door, which the developer and condo owners insist bears some responsibility.
One source told us that residents would probably be able to stay in the building while the repairs were under way.
“Conceptually, it’s workable, but they need to vet it out,” the source said.
Another source told us the vetting needed to be done quickly. “There is a sense that we need to start doing something sooner rather than later because of the continuing sinkage,” the source said.
That sinkage shows no sign of easing up. The new engineering report by Arup shows that the rate of sinking remains steady. There is also evidence of continued cracking in the basement, according to the report we’ve obtained.
“It’s approximately the same rate of sinking and tilting as before,” said one of the sources.
P.J. Johnston, spokesman for Millennium Partners, declined to comment on the talks or the latest engineering report, but said, “Our highest priority has always been to fix the building.
“We’ve been working closely with the (homeowners association) throughout the mediation process, and we’re optimistic that we’ll reach an agreement on the fix,” Johnston said. “To do so, it’s imperative that we respect the confidentiality of the mediation process. Any proposed solutions are preliminary until an agreement is reached.”
Jack Gallagher, a spokesman for the San Francisco city administrator’s office, which is reviewing all downtown highrise construction in the wake of the Millennium Tower’s problems, said no repair plan has been submitted to the city for permits. “And since we haven’t seen any of their plans, we have nothing we can comment on,” he said.
Bill Strawn, spokesman for the Department of Building Inspection, said his office had just received the latest engi-