Millennium Tower officials are assuring residents that work on the troubled “fix” for the leaning high-rise will restart soon, after project engineers refine construction methods so as to prevent future accelerated sinking and tilting of the luxury high-rise.
In a notice distributed over the Labor Day weekend, the Millennium Tower’s general manager briefs residents on the status of the currently stalled perimeter pile upgrade project – a 22-month, $100 million effort to install new piles to bedrock along the two sides sinking and tilting the most.
“We have been assured that the building remains safe, and we anticipate that construction with some modifications, coupled with daily monitoring, will resume shortly,” said tower general manager James Zaratin in the Sept. 5 bulletin.
Zaratin explained that the recently accelerated sinking “stopped almost immediately after construction was halted” last month. The current rate is equivalent to the rate before the work started, the notice says.
In early August, part of the project was halted to help understand what was causing the building to sink much more rapidly than before work began in May. But the tower continued to sink and tilt more dramatically as crews focused on the drilling needed to install two-foot wide casings down to bedrock.
All work was officially halted on Aug. 23, after monitoring data showed that in the three months since May, the building had settled an inch and shifted five additional inches at the top. Currently, the tower leans 22 inches toward Fremont Street.
Fix engineers tell city officials that part of the problem is that the holes crews drilled to install piles to bedrock were slightly too big around. Experts say surrounding soil likely shifted to fill the void created between the oversized hole and the pile. That “lost ground,” they say, likely destabilized the earth supporting the existing foundation.
Zaratin assured residents they’re working with the fix engineers and the city’s engineering design review panel to refine drilling methods to minimize the ground disturbance.
But San Francisco Supervisor Aaron Peskin is skeptical. He said Wednesday he will summon experts to assess the plight of the building during the as-yet unscheduled hearing that he called for Tuesday.
“There’s a lot under this rock and I’m about to shine some light on it,” Peskin said, adding that he no longer trusts the current engineering review panel. It was that panel that vouched for the fix back in 2019 and has continued to support the fix team’s efforts.
“I’m concerned that they are reviewing their own work,” Peskin said of the review panel. “We need third party, independent oversight.”
Peskin said he wants to hear from those outside experts before work resumes.
One of the experts the city has relied on the past – but did not heed in the case of the Millennium Tower fix — is veteran geotechnical engineer Robert Pyke.
“The overall fix that they’re engaged in is the problem — it’s not a satisfactory fix for the long term condition,” Pyke told our Investigative Unit.
Pyke was among a total of three engineers who objected to the proposed fix in July 2019. While records show the engineering review panel was briefed about those concerns, it approved the fix project a month later without directly consulting the engineers who raised them.
“At a minimum, I thought that the city’s Department of Building Inspection or the (engineering review) panel would want to talk to me,” Pyke recalled. “I was just blown off.”
So far, that design review panel has expressed full confidence in the fix team’s work. Meanwhile, the city has yet to release the data that has been collected since mid-August. Data that could confirm what the association told residents about building’s eased rate of sinking since pile installation work was suspended.
Source: NBC Bay Area